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Safa BT, Rosenbohm J, Esfahani AM, Minnick G, Moghaddam AO, Lavrik NV, Huang C, Charras G, Kabla A, Yang R. Sustained Strain Applied at High Rates Drives Dynamic Tensioning in Epithelial Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.31.606021. [PMID: 39131373 PMCID: PMC11312595 DOI: 10.1101/2024.07.31.606021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Epithelial cells experience long lasting loads of different magnitudes and rates. How they adapt to these loads strongly impacts tissue health. Yet, much remains unknown about their stress evolution under sustained strain. Here, by subjecting cell pairs to sustained strain, we report a bimodal stress response, where in addition to the typically observed stress relaxation, a subset of cells exhibits a dynamic tensioning process with significant elevation in stress within 100s, resembling active pulling-back in muscle fibers. Strikingly, the fraction of cells exhibiting tensioning increases with increasing strain rate. The tensioning response is accompanied by actin remodeling, and perturbation to actin abrogates it, supporting cell contractility's role in the response. Collectively, our data show that epithelial cells adjust their tensional states over short timescales in a strain-rate dependent manner to adapt to sustained strains, demonstrating that the active pulling-back behavior could be a common protective mechanism against environmental stress.
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Affiliation(s)
- Bahareh Tajvidi Safa
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jordan Rosenbohm
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Amir Monemian Esfahani
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Grayson Minnick
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Amir Ostadi Moghaddam
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Nickolay V. Lavrik
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Changjin Huang
- School of Mechanical & Aerospace Engineering, Nanyang Technological University, Singapore, Republic of Singapore
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, London, UK
- Department of Cell and Developmental Biology, University College London, London, UK
- Institute for the Physics of Living Systems, University College London, London, UK
| | - Alexandre Kabla
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Ruiguo Yang
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
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Cho H, Dohi T, Wakai H, Quong WL, Linh NDT, Usami S, Ogawa R. In the face and neck, keloid scar distribution is related to skin thickness and stiffness changes associated with movement. Wound Repair Regen 2024; 32:419-428. [PMID: 38602106 DOI: 10.1111/wrr.13180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 02/25/2024] [Accepted: 04/01/2024] [Indexed: 04/12/2024]
Abstract
Keloid scars tend to occur in high-tension sites due to mechanical stimuli that are involved in their development. To date, a detailed analysis of keloid distribution focused specifically on facial and neck areas has not been reported, and limited literature exists as to the related mechanical factors. To rectify this deficiency of knowledge, we first quantified the facial and neck keloid distribution observed clinically in 113 patients. Subsequently, we performed a rigorous investigation into the mechanical factors and their associated changes at these anatomic sites in healthy volunteers without a history of pathologic scarring. The association between keloid-predilection sites and sebaceous gland-dense and acne-prone sites was also examined. To assess skin stretch, thickness and stiffness, VECTRA, ultrasound and indentometer were utilised. Baseline skin stiffness and thickness were measured, as well as the magnitude of change in these values associated with facial expression and postural changes. Within the face and neck, keloids were most common near the mandibular angle (41.3%) and lateral submental (20.0%) regions. These areas of increased keloid incidence were not associated with areas more dense in sebaceous glands, nor linked consistently with acne-susceptible regions. Binomial logistic regression revealed that changes in skin stiffness and thickness related to postural changes significantly predicted keloid distribution. Skin stiffness and thickness changes related to prolonged mechanical forces (postural changes) are most pronounced at sites of high keloid predilection. This finding further elucidates the means by which skin stretch and tension are related to keloid development. As a more detailed analysis of mechanical forces on facial and neck skin, this study evaluates the nuances of multiple skin-mechanical properties, and their changes in a three-dimensional framework. Such factors may be critical to better understanding keloid progression and development in the face and neck.
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Affiliation(s)
- Hoyu Cho
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
| | - Teruyuki Dohi
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
| | - Hanae Wakai
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
| | - Whitney Laurel Quong
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
- Department of Plastic, Reconstructive, and Aesthetic Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Nguyen Doan Tien Linh
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
| | - Satoshi Usami
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
- Graduate School of Education, The University of Tokyo, Tokyo, Japan
| | - Rei Ogawa
- Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Tokyo, Japan
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3
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Chaturvedi P, Kroon W, Zanelli G, Worsley PR. An exploratory study of structural and microvascular changes in the skin following electrical shaving using optical coherence topography. Skin Res Technol 2024; 30:e13830. [PMID: 38951871 PMCID: PMC11217022 DOI: 10.1111/srt.13830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 06/11/2024] [Indexed: 07/03/2024]
Abstract
BACKGROUND Consumer products such as electrical shavers exert a combination of dynamic loading in the form of pressure and shear on the skin. This mechanical stimulus can lead to discomfort and skin tissue responses characterised as "Skin Sensitivity". To minimise discomfort following shaving, there is a need to establish specific stimulus-response relationships using advanced tools such as optical coherence tomography (OCT). OBJECTIVE To explore the spatial and temporal changes in skin morphology and microvascular function following an electrical shaving stimulus. METHODS Ten healthy male volunteers were recruited. The study included a 60-s electrical shaving stimulus on the forearm, cheek and neck. Skin parameters were recorded at baseline, 20 min post stimulus and 24 h post stimulus. Structural and dynamic skin parameters were estimated using OCT, while transepidermal water loss (TEWL) was recorded to provide reference values for skin barrier function. RESULTS At baseline, six of the eight parameters revealed statistically significant differences between the forearm and the facial sites, while only surface roughness (Rq) and reflectivity were statistically different (p < 0.05) between the cheek and neck. At 20 min post shaving, there was a significant increase in the TEWL values accompanied by increased blood perfusion, with varying magnitude of change dependent on the anatomical site. Recovery characteristics were observed 24 h post stimulus with most parameters returning to basal values, highlighting the transient influence of the stimulus. CONCLUSIONS OCT parameters revealed spatial and temporal differences in the skin tissue response to electrical shaving. This approach could inform shaver design and prevent skin sensitivity.
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Affiliation(s)
- Pakhi Chaturvedi
- Skin Sensing Research GroupSchool of Health Sciences, University of SouthamptonSouthamptonUK
- Philips Consumer Lifestyle B.V.DrachtenThe Netherlands
| | - Wilco Kroon
- Philips Consumer Lifestyle B.V.DrachtenThe Netherlands
| | | | - Peter R. Worsley
- Skin Sensing Research GroupSchool of Health Sciences, University of SouthamptonSouthamptonUK
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4
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Morecroft R, Tomlinson K, Lewis R, Carré M. Friction between human skin and incontinence pads in the presence of barrier protection products. Proc Inst Mech Eng H 2024; 238:644-654. [PMID: 37300487 PMCID: PMC11318204 DOI: 10.1177/09544119231178477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/10/2023] [Indexed: 06/12/2023]
Abstract
This novel experimental work aims to bring further knowledge of frictional performance of common barrier products used in the treatment of incontinence-associated dermatitis and determine how the skin-pad interface changes when a treatment is applied to the skin. Key data is reported and there is an in-depth analysis into friction profiles which reveals great differences between how different skin-pad tribosystems operate when exposed to commercially available barrier treatments. In a wet-pad state Barrier cream A (3M™ Cavilon™ Barrier cream) reduced friction and had much lower dynamic and static coefficients of friction than the other barrier treatments (Barrier cream B (Sorbaderm Barrier cream) and the Barrier spray C (Sorbaderm Barrier spray)). Barrier cream A provided stable friction coefficients in reciprocating sliding, whereas the other treatments, and untreated skin, did not display this unique characteristic. The barrier spray gave rise to high static friction coefficients and exhibited the most stick-slip. All three candidate barrier protection products were found to reduce directional differences in the static coefficient of friction: indicative of reduced shear loading. Knowledge of the desirable frictional properties would drive innovation in product development, and benefit companies, clinicians and users.
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Affiliation(s)
- Rachel Morecroft
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
| | - Katherine Tomlinson
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
| | - Roger Lewis
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
| | - Matt Carré
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
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Chen B, Zhang P, Tan K, Zhu H, Li Z, Li C, Wang Z. Characterization of human skin under tension using terahertz time domain spectroscopy. JOURNAL OF BIOPHOTONICS 2024; 17:e202400003. [PMID: 38651304 DOI: 10.1002/jbio.202400003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/16/2024] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
This paper introduces a spectral analysis method for monitoring the human skin in vivo based on a combination of terahertz time-domain spectroscopy (THz-TDS) and optical coherence tomography (OCT). The method can quantitatively measure the refractive index, thickness and transmission coefficient of epidermis, and the refractive index of dermis in natural, as well as the tension condition of the skin. An optically reflective model for the multilayer structure of the skin is first established. The initial thickness of the epidermis is then measured by OCT as a known quantity for the established model. By fitting the established model to the experimentally obtained THz-TDS signals, the above parameters of the skin can be calibrated. Furthermore, the dependence of these skin parameters on the tension status are investigated. This study provides a means for terahertz technology to measure the skin in vivo.
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Affiliation(s)
- Baitong Chen
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Pengyan Zhang
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Keyu Tan
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Hengxin Zhu
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Zixuan Li
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Chuanwei Li
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Zhiyong Wang
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, China
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6
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Su R, Wang L, Han F, Bian S, Meng F, Qi W, Zhai X, Li H, Wu J, Pan X, Pan H, Guo P, Lu WW, Liu Z, Zhao X. A highly stretchable smart dressing for wound infection monitoring and treatment. Mater Today Bio 2024; 26:101107. [PMID: 38952538 PMCID: PMC11216007 DOI: 10.1016/j.mtbio.2024.101107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 05/23/2024] [Accepted: 05/31/2024] [Indexed: 07/03/2024] Open
Abstract
Smart dressings integrated with bioelectronics have attracted considerable attention and become promising solutions for skin wound management. However, due to the mechanical distinction between human body and the interface of electronics, previous smart dressings often suffered obvious degradation in electrical performance when attached to the soft and curvilinear wound sites. Here, we report a stretchable dressing integrated with temperature and pH sensor for wound status monitoring, as well as an electrically controlled drug delivery system for infection treatment. The wound dressing was featured with the deployment of liquid metal for seamless connection between rigid electrical components and gold particle-based electrodes, achieving a stretchable soft-hard interface. Stretching tests showed that both the sensing system and drug delivery system exhibited good stretchability and long-term stable conductivity with the resistance change rate less than 6 % under 50 % strain. Animal experiments demonstrated that the smart dressing was capable of detecting bacterial infection via the biomarkers of temperature and pH value and the infection factors of wound were significantly improved with therapy through electrically controlled antibiotics releasing. This proof-of-concept prototype has potential to significantly improve management of the wound, especially those with dynamic strain.
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Affiliation(s)
- Rui Su
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Institute of Materials for Energy and Environment, State Key Laboratory of Bio-fibers and Eco-textiles, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Liangliang Wang
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Fei Han
- Neural Engineering Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China
| | - Shaoquan Bian
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Fengzhen Meng
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Weichen Qi
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong 999077, China
| | - Xinyun Zhai
- Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China
| | - Hanfei Li
- Neural Engineering Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China
| | - Jun Wu
- Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong-Shenzhen Hospital, Shenzhen 518053, China
| | - Xiaohua Pan
- Southern Medical University, Shenzhen Bao'an People's Hospital, Dept Orthoped & Traumatol, Shenzhen 518101, China
| | - Haobo Pan
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Peizhi Guo
- Institute of Materials for Energy and Environment, State Key Laboratory of Bio-fibers and Eco-textiles, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - William W. Lu
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong 999077, China
- Department of Pharmaceutical Materials and Translational Medicine, Faculty of Pharmaceutical Sciences, Shenzhen University of Advanced Technology, Shenzhen 518083, China
| | - Zhiyuan Liu
- Neural Engineering Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China
- Standard Robots Co.,Ltd, Room 405, Building D, Huafeng International Robot Fusen Industrial Park, Hangcheng Avenue, Guxing Community, Xixiang Street, Baoan District, Shenzhen, 518055, China
| | - Xiaoli Zhao
- Research Center for Human Tissue and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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7
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Gao Y, Li B, Zhang L, Zhang X, Xin X, Xie S, Lee RA, Li K, Zhao W, Cheng H. Ultraconformal Skin-Interfaced Sensing Platform for Motion Artifact-Free Monitoring. ACS APPLIED MATERIALS & INTERFACES 2024; 16:27952-27960. [PMID: 38808703 DOI: 10.1021/acsami.4c04357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Capable of directly capturing various physiological signals from human skin, skin-interfaced bioelectronics has emerged as a promising option for human health monitoring. However, the accuracy and reliability of the measured signals can be greatly affected by body movements or skin deformations (e.g., stretching, wrinkling, and compression). This study presents an ultraconformal, motion artifact-free, and multifunctional skin bioelectronic sensing platform fabricated by a simple and user-friendly laser patterning approach for sensing high-quality human physiological data. The highly conductive membrane based on the room-temperature coalesced Ag/Cu@Cu core-shell nanoparticles in a mixed solution of polymers can partially dissolve and locally deform in the presence of water to form conformal contact with the skin. The resulting sensors to capture improved electrophysiological signals upon various skin deformations and other biophysical signals provide an effective means to monitor health conditions and create human-machine interfaces. The highly conductive and stretchable membrane can also be used as interconnects to connect commercial off-the-shelf chips to allow extended functionalities, and the proof-of-concept demonstration is highlighted in an integrated pulse oximeter. The easy-to-remove feature of the resulting device with water further allows the device to be applied on delicate skin, such as the infant and elderly.
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Affiliation(s)
- Yuyan Gao
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Bowen Li
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Ling Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, Guangdong, China
| | - Xianzhe Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Xin Xin
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Senpei Xie
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, Guangdong, China
| | - Ryan Allen Lee
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kang Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, Guangdong, China
| | - Weiwei Zhao
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, Guangdong, China
| | - Huanyu Cheng
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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8
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Zhang F, Zhang Y, Qian S, Qian X, Jiao J, Ma B, Chen J, Cheng H, Li X, Lin Y, Li H, Cui C, Chen M. Injectable and Conductive Nanomicelle Hydrogel with α-Tocopherol Encapsulation for Enhanced Myocardial Infarction Repair. ACS NANO 2024; 18:10216-10229. [PMID: 38436241 DOI: 10.1021/acsnano.4c00509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Substantial advancements have been achieved in the realm of cardiac tissue repair utilizing functional hydrogel materials. Additionally, drug-loaded hydrogels have emerged as a research hotspot for modulating adverse microenvironments and preventing left ventricular remodeling after myocardial infarction (MI), thereby fostering improved reparative outcomes. In this study, diacrylated Pluronic F127 micelles were used as macro-cross-linkers for the hydrogel, and the hydrophobic drug α-tocopherol (α-TOH) was loaded. Through the in situ synthesis of polydopamine (PDA) and the incorporation of conductive components, an injectable and highly compliant antioxidant/conductive composite FPDA hydrogel was constructed. The hydrogel exhibited exceptional stretchability, high toughness, good conductivity, cell affinity, and tissue adhesion. In a rabbit model, the material was surgically implanted onto the myocardial tissue, subsequent to the ligation of the left anterior descending coronary artery. Four weeks postimplantation, there was discernible functional recovery, manifesting as augmented fractional shortening and ejection fraction, alongside reduced infarcted areas. The findings of this investigation underscore the substantial utility of FPDA hydrogels given their proactive capacity to modulate the post-MI infarct microenvironment and thereby enhance the therapeutic outcomes of myocardial infarction.
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Affiliation(s)
- Feng Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Yike Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Sichong Qian
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Beijing 100029, China
| | - Xuetian Qian
- Department of Gastroenterology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Jincheng Jiao
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Biao Ma
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Jiuzhou Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Hongyi Cheng
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Xiaopei Li
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Yongping Lin
- Department of Cardiology, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou 225300, China
| | - Haiyang Li
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Beijing 100029, China
| | - Chang Cui
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
| | - Minglong Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, China
- Department of Cardiology, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou 225300, China
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9
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Huo Z, Wang S, Wei H, Cheng X, Li L, Li C, Wang Z. Dynamic model for the strain-modulated spectral reflectance of the human skin in vivo. BIOMEDICAL OPTICS EXPRESS 2024; 15:2238-2250. [PMID: 38633061 PMCID: PMC11019687 DOI: 10.1364/boe.507361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 04/19/2024]
Abstract
Hyperspectral imaging (HSI) offers a wealth of information regarding human skin. In this study, we established a dynamic skin spectral reflectance model (DSSR) relating the reflectance to skin surface strain, considering multi physiological and physical parameters of the skin. Experimentally, by HSI, we measured the reflectance variance of the forearm skin in vivo caused by the surface strain, and assessed these key parameters. For the human skin in vivo, within the strain range covered in this paper, stretching increases spectral reflectance, while compression decreases it. Our proposed model provides a possibility for non-contact strain measurement and health monitoring on the skin in vivo based on HSI.
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Affiliation(s)
- Zongze Huo
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Shibin Wang
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Huixin Wei
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Xuanshi Cheng
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Linan Li
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Chuanwei Li
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Zhiyong Wang
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
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10
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Fu X, Taghizadeh A, Taghizadeh M, Li CJ, Lim NK, Lee J, Kim HS, Kim H. Targeting Nuclear Mechanics Mitigates the Fibroblast Invasiveness in Pathological Dermal Scars Induced by Matrix Stiffening. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308253. [PMID: 38353381 PMCID: PMC11022731 DOI: 10.1002/advs.202308253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/04/2024] [Indexed: 04/18/2024]
Abstract
Pathological dermal scars such as keloids present significant clinical challenges lacking effective treatment options. Given the distinctive feature of highly stiffened scar tissues, deciphering how matrix mechanics regulate pathological progression can inform new therapeutic strategies. Here, it is shown that pathological dermal scar keloid fibroblasts display unique metamorphoses to stiffened matrix. Compared to normal fibroblasts, keloid fibroblasts show high sensitivity to stiffness rather than biochemical stimulation, activating cytoskeletal-to-nuclear mechanosensing molecules. Notably, keloid fibroblasts on stiff matrices exhibit nuclear softening, concomitant with reduced lamin A/C expression, and disrupted anchoring of lamina-associated chromatin. This nuclear softening, combined with weak adhesion and high contractility, facilitates the invasive migration of keloid fibroblasts through confining matrices. Inhibiting lamin A/C-driven nuclear softening, via lamin A/C overexpression or actin disruption, mitigates such invasiveness of keloid fibroblasts. These findings highlight the significance of the nuclear mechanics of keloid fibroblasts in scar pathogenesis and propose lamin A/C as a potential therapeutic target for managing pathological scars.
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Affiliation(s)
- Xiangting Fu
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
| | - Ali Taghizadeh
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
| | - Mohsen Taghizadeh
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
| | - Cheng Ji Li
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
| | - Nam Kyu Lim
- Department of Plastic and Reconstructive SurgeryDankook University Hospital (DKUH)Cheonan31116Republic of Korea
- Dankook Physician Scientist Research CenterDankook University Hospital (DKUH)Cheonan31116Republic of Korea
| | - Jung‐Hwan Lee
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
- Department of Biomaterials Science, College of DentistryDankook UniversityCheonan31116Republic of Korea
- Cell & Matter InstituteDankook UniversityCheonan31116Republic of Korea
- Mechanobiology Dental Medicine Research CenterDankook UniversityCheonan31116Republic of Korea
| | - Hye Sung Kim
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
- Mechanobiology Dental Medicine Research CenterDankook UniversityCheonan31116Republic of Korea
| | - Hae‐Won Kim
- Institute of Tissue Regeneration Engineering (ITREN)Dankook UniversityCheonan31116Republic of Korea
- Department of Nanobiomedical Science and BK21 Global Research Center for Regeneration MedicineDankook UniversityCheonan31116Republic of Korea
- Department of Biomaterials Science, College of DentistryDankook UniversityCheonan31116Republic of Korea
- Cell & Matter InstituteDankook UniversityCheonan31116Republic of Korea
- Mechanobiology Dental Medicine Research CenterDankook UniversityCheonan31116Republic of Korea
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11
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Kim H, Lee J, Heo U, Jayashankar DK, Agno KC, Kim Y, Kim CY, Oh Y, Byun SH, Choi B, Jeong H, Yeo WH, Li Z, Park S, Xiao J, Kim J, Jeong JW. Skin preparation-free, stretchable microneedle adhesive patches for reliable electrophysiological sensing and exoskeleton robot control. SCIENCE ADVANCES 2024; 10:eadk5260. [PMID: 38232166 DOI: 10.1126/sciadv.adk5260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/18/2023] [Indexed: 01/19/2024]
Abstract
High-fidelity and comfortable recording of electrophysiological (EP) signals with on-the-fly setup is essential for health care and human-machine interfaces (HMIs). Microneedle electrodes allow direct access to the epidermis and eliminate time-consuming skin preparation. However, existing microneedle electrodes lack elasticity and reliability required for robust skin interfacing, thereby making long-term, high-quality EP sensing challenging during body movement. Here, we introduce a stretchable microneedle adhesive patch (SNAP) providing excellent skin penetrability and a robust electromechanical skin interface for prolonged and reliable EP monitoring under varying skin conditions. Results demonstrate that the SNAP can substantially reduce skin contact impedance under skin contamination and enhance wearing comfort during motion, outperforming gel and flexible microneedle electrodes. Our wireless SNAP demonstration for exoskeleton robot control shows its potential for highly reliable HMIs, even under time-dynamic skin conditions. We envision that the SNAP will open new opportunities for wearable EP sensing and its real-world applications in HMIs.
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Affiliation(s)
- Heesoo Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Juhyun Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ung Heo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | | | - Karen-Christian Agno
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Yeji Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Choong Yeon Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Youngjun Oh
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sang-Hyuk Byun
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Bohyung Choi
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hwayeong Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Woon-Hong Yeo
- IEN Center for Wearable Intelligent Systems and Healthcare at the Institute for Electronics and Nanotechnology, Georgia Institute of Technology, Atlanta, GA 30332, USA
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, GA 30332, USA
- Parker H. Petit Institute for Bioengineering and Biosciences, Institute for Materials, Neural Engineering Center, Institute for Robotics and Intelligent Machines, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Zhuo Li
- Department of Material Science, Fudan University, Shanghai 200433, China
| | - Seongjun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jianliang Xiao
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Jung Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jae-Woong Jeong
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- KAIST Institute for Health Science and Technology, Daejeon 34141, Republic of Korea
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12
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Golparvar A, Thenot L, Boukhayma A, Carrara S. Soft Epidermal Paperfluidics for Sweat Analysis by Ratiometric Raman Spectroscopy. BIOSENSORS 2023; 14:12. [PMID: 38248389 PMCID: PMC10812966 DOI: 10.3390/bios14010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/11/2023] [Accepted: 12/19/2023] [Indexed: 01/23/2024]
Abstract
The expanding interest in digital biomarker analysis focused on non-invasive human bodily fluids, such as sweat, highlights the pressing need for easily manufactured and highly efficient soft lab-on-skin solutions. Here, we report, for the first time, the integration of microfluidic paper-based devices (μPAD) and non-enhanced Raman-scattering-enabled optical biochemical sensing (Raman biosensing). Their integration merges the enormous benefits of μPAD, with high potential for commercialization and use in resource-limited settings, with biorecognition-element-free (but highly selective) optical Raman biosensing. The introduced thin (0.36 mm), ultra-lightweight (0.19 g), and compact footprint (3 cm2) opto-paperfluidic sweat patch is flexible, stretchable, and conforms, irritation-free, to hairless or minimally haired body regions to enable swift sweat collection. As a great advantage, this new bio-chemical sensory system excels through its absence of onboard biorecognition elements (bioreceptor-free) and omission of plasmonic nanomaterials. The proposed easy fabrication process is adaptable to mass production by following a fully sustainable and cost-effective process utilizing only basic tools by avoiding typically employed printing or laser patterning. Furthermore, efficient collection and transportation of precise sweat volumes, driven exclusively by the wicking properties of porous materials, shows high efficiency in liquid transportation and reduces biosensing latency by a factor of 5 compared to state-of-the-art epidermal microfluidics. The proposed unit enables electronic chip-free and imaging-less visual sweat loss quantification as well as optical biochemical analysis when coupled with Raman spectroscopy. We investigated the multimodal quantification of sweat urea and lactate levels ex vivo (with syntactic sweat including +30 sweat analytes on porcine skin) and achieved a linear dynamic range from 0 to 100 mmol/L during fully dynamic continuous flow characterization.
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Affiliation(s)
- Ata Golparvar
- Bio/CMOS Interfaces (BCI) Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2000 Neuchatel, Switzerland
| | - Lucie Thenot
- Bio/CMOS Interfaces (BCI) Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2000 Neuchatel, Switzerland
| | | | - Sandro Carrara
- Bio/CMOS Interfaces (BCI) Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2000 Neuchatel, Switzerland
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13
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Luo H, Jin T, Zhang Y, Tian B, Zhang Y, Wang D. A skin-integrated device for neck posture monitoring and correction. MICROSYSTEMS & NANOENGINEERING 2023; 9:150. [PMID: 38033991 PMCID: PMC10682425 DOI: 10.1038/s41378-023-00613-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/19/2023] [Accepted: 09/26/2023] [Indexed: 12/02/2023]
Abstract
Cervical spondylosis is a common disease that is often caused by long-term abnormal cervical curvature due to activities such as reading books and using computers or smartphones. This paper explores building an untethered and skin-integrated device in an e-skin form factor to monitor and haptically correct neck posture. The proposed design features a multilayered structure that integrates all flexible electronic circuits and components into a compact skin space while being untethered and skin conformal. An accelerometer in the e-skin attaches to the neck for posture sensing, while four vibration actuators closely touch the neck skin to provide localized vibrotactile stimuli that encode four-direction correction cues of neck flexion ± α and lateral bending ± β . To ensure the reliability of posture sensing and vibrotactile rendering during neck movement, it is necessary to prevent the e-skin device from shifting position. Thus, a hollow structure-based method is implemented for stably attaching the e-skin to the neck skin. Experiments validated the e-skin device's sensing precision, skin-conformal compliance, stickiness, stability and effectiveness during the motion of neck postures, including its discrimination of localized four-direction vibrotactile cues. A user study verified the device's performance for sensing and correcting different abnormal neck postures during activities such as using smartphones, reading books, and processing computer files. The proposed e-skin device may create opportunities for more convenient cervical spondylosis prevention and rehabilitation.
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Affiliation(s)
- Hu Luo
- State Key Lab of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, 100191 Beijing, China
| | - Tianhao Jin
- State Key Lab of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, 100191 Beijing, China
| | - Yu Zhang
- School of General Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, China
| | - Bohao Tian
- State Key Lab of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, 100191 Beijing, China
| | - Yuru Zhang
- State Key Lab of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, 100191 Beijing, China
| | - Dangxiao Wang
- State Key Lab of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, 100191 Beijing, China
- Peng Cheng Laboratory, Shenzhen, 518055 China
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14
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Bril M, Saberi A, Jorba I, van Turnhout MC, Sahlgren CM, Bouten CV, Schenning AP, Kurniawan NA. Shape-Morphing Photoresponsive Hydrogels Reveal Dynamic Topographical Conditioning of Fibroblasts. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303136. [PMID: 37740666 PMCID: PMC10625123 DOI: 10.1002/advs.202303136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/22/2023] [Indexed: 09/25/2023]
Abstract
The extracellular environment defines a physical boundary condition with which cells interact. However, to date, cell response to geometrical environmental cues is largely studied in static settings, which fails to capture the spatiotemporally varying cues cells receive in native tissues. Here, a photoresponsive spiropyran-based hydrogel is presented as a dynamic, cell-compatible, and reconfigurable substrate. Local stimulation with blue light (455 nm) alters hydrogel swelling, resulting in on-demand reversible micrometer-scale changes in surface topography within 15 min, allowing investigation into cell response to controlled geometry actuations. At short term (1 h after actuation), fibroblasts respond to multiple rounds of recurring topographical changes by reorganizing their nucleus and focal adhesions (FA). FAs form primarily at the dynamic regions of the hydrogel; however, this propensity is abolished when the topography is reconfigured from grooves to pits, demonstrating that topographical changes dynamically condition fibroblasts. Further, this dynamic conditioning is found to be associated with long-term (72 h) maintenance of focal adhesions and epigenetic modifications. Overall, this study offers a new approach to dissect the dynamic interplay between cells and their microenvironment and shines a new light on the cell's ability to adapt to topographical changes through FA-based mechanotransduction.
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Affiliation(s)
- Maaike Bril
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
| | - Aref Saberi
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
| | - Ignasi Jorba
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
| | - Mark C. van Turnhout
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
| | - Cecilia M. Sahlgren
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Faculty of Science and EngineeringÅbo Akademi UniversityTurkuFI‐20520Finland
| | - Carlijn V.C. Bouten
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
| | - Albert P.H.J. Schenning
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Department of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5612 AEThe Netherlands
| | - Nicholas A. Kurniawan
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhoven5600 MBThe Netherlands
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15
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Kho ASK, Béguin S, O'Cearbhaill ED, Ní Annaidh A. Mechanical characterisation of commercial artificial skin models. J Mech Behav Biomed Mater 2023; 147:106090. [PMID: 37717289 DOI: 10.1016/j.jmbbm.2023.106090] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/19/2023] [Accepted: 08/23/2023] [Indexed: 09/19/2023]
Abstract
Understanding of the mechanical properties of skin is crucial in evaluating the performance of skin-interfacing medical devices. Artificial skin models (ASMs) have rapidly gained attention as they are able to overcome the challenges in ethically sourcing consistent and representative ex vivo animal or human tissue models. Although some ASMs have become commercialised, a thorough understanding of the mechanical properties of the skin models is crucial to ensure that they are suitable for the purpose of the study. In the present study, skin and fat layers of ASMs (Simulab®, LifeLike®, SynDaver® and Parafilm®) were mechanically characterised through hardness, needle insertion, tensile and compression testing. Different boundary constraint conditions (minimally and highly constrained) were investigated for needle insertion testing, while anisotropic properties of the skin models were investigated through different specimen orientations during tensile testing. Analysis of variance (ANOVA) tests were performed to compare the mechanical properties between the skin models. Properties of the skin models were compared against literature to determine the suitability of the skin models based on the material property of interest. All skin models offer relatively consistent mechanical performance, providing a solid basis for benchtop evaluation of skin-interfacing medical device performance. Through prioritising models with mechanical properties that are consistent with human skin data, and with limited variance, researchers can use the data presented here as a toolbox to select the most appropriate ASM for their particular application.
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Affiliation(s)
- Antony S K Kho
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; I-Form Advanced Manufacturing Research Centre, School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland; BD Research Centre Ireland Ltd, Carysfort Avenue, Blackrock, Ireland
| | - Steve Béguin
- BD Research Centre Ireland Ltd, Carysfort Avenue, Blackrock, Ireland
| | - Eoin D O'Cearbhaill
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; I-Form Advanced Manufacturing Research Centre, School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland; UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland; The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Aisling Ní Annaidh
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; I-Form Advanced Manufacturing Research Centre, School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland; UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland.
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16
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Li J, Carlos C, Zhou H, Sui J, Wang Y, Silva-Pedraza Z, Yang F, Dong Y, Zhang Z, Hacker TA, Liu B, Mao Y, Wang X. Stretchable piezoelectric biocrystal thin films. Nat Commun 2023; 14:6562. [PMID: 37848410 PMCID: PMC10582159 DOI: 10.1038/s41467-023-42184-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/02/2023] [Indexed: 10/19/2023] Open
Abstract
Stretchability is an essential property for wearable devices to match varying strains when interfacing with soft tissues or organs. While piezoelectricity has broad application potentials as tactile sensors, artificial skins, or nanogenerators, enabling tissue-comparable stretchability is a main roadblock due to the intrinsic rigidity and hardness of the crystalline phase. Here, an amino acid-based piezoelectric biocrystal thin film that offers tissue-compatible omnidirectional stretchability with unimpaired piezoelectricity is reported. The stretchability was enabled by a truss-like microstructure that was self-assembled under controlled molecule-solvent interaction and interface tension. Through the open and close of truss meshes, this large scale biocrystal microstructure was able to endure up to 40% tensile strain along different directions while retained both structural integrity and piezoelectric performance. Built on this structure, a tissue-compatible stretchable piezoelectric nanogenerator was developed, which could conform to various tissue surfaces, and exhibited stable functions under multidimensional large strains. In this work, we presented a promising solution that integrates piezoelectricity, stretchability and biocompatibility in one material system, a critical step toward tissue-compatible biomedical devices.
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Affiliation(s)
- Jun Li
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Corey Carlos
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Hao Zhou
- Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, China
| | - Jiajie Sui
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Yikai Wang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Zulmari Silva-Pedraza
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Fan Yang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, Shanghai, 200025, China
| | - Yutao Dong
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ziyi Zhang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Timothy A Hacker
- Cardiovascular Research Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Bo Liu
- Department of Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Yanchao Mao
- Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, China.
| | - Xudong Wang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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17
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Kao AR, Landsman ZT, Gerling GJ, Loghmani MT. Optical Measurements of the Skin Surface to Infer Bilateral Distinctions in Myofascial Tissue Stiffness. WORLD HAPTICS CONFERENCE. WORLD HAPTICS CONFERENCE 2023; 2023:244-251. [PMID: 38618515 PMCID: PMC11016193 DOI: 10.1109/whc56415.2023.10224420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
About half the U.S. adult population suffers from chronic neuromusculoskeletal pain. While its evaluation and treatment are widely addressed by therapies using soft tissue manipulation (STM), their efficacy is based upon clinician judgment. Robust biomarkers are needed to quantify the effects of STM on patient outcomes. Among noninvasive methods to quantify the mechanics of myofascial tissue, most are limited to small (<10 mm2), localized regions of interest. In contrast, we develop an approach to optically simultaneously measure a larger (~100 cm2) field of deformation at the skin surface. Biomarkers based on skin lateral mobility are derived to infer distinctions in myofascial tissue stiffness. In specific, three cameras track ink speckles whose fields of deformation and stretch are resolved with digital image correlation. Their ability to differentiate bilateral distinctions of the cervicothoracic region is evaluated with four participants, as a licensed clinician performs STM. The results indicate that the optically derived surface biomarkers can differentiate bilateral differences in skin mobility, with trend directions within a participant similar to measurements with an instrumented force probe. These findings preliminarily suggest skin surface measurements are capable of inferring underlying myofascial tissue stiffness, although further confirmation will require a larger, more diverse group of participants.
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Affiliation(s)
- Anika R Kao
- University of Virginia, Charlottesville, USA
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18
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Moonen EJM, Ul Islam T, van Kemenade S, Pelssers E, Heikenfeld J, den Toonder JMJ. A versatile artificial skin platform for sweat sensor development. LAB ON A CHIP 2023; 23:2268-2275. [PMID: 37043225 DOI: 10.1039/d3lc00109a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Research targeting the development of on-body sensors has been significantly growing in recent years - an example is on-skin sweat sensing. However, the wide inter and intra person variability of skin characteristics make in vivo testing of these sensors and included materials such as skin adhesives difficult, which hampers especially the initial development phase of such wearables. Besides the development of wearable sweat sensors, companies developing deodorants, cosmetics, medical adhesives and wearable textiles now need to perform expensive human subjects testing with little control over the exact sweat mechanisms. Hence, there is a need for a realistic, adaptable and stable test platform, or artificial skin. We present a versatile artificial skin platform that faithfully recapitulates skin topography, active sweat pores, skin wetting behaviour and sweat rate, and that can be tuned to mimic the specifications of the targeted body location and sweating characteristics. The developed artificial skin is capable of generating sweat rates as low as 0.1 nL min-1 pore-1 and as high as 100 nL min-1 pore-1, spanning the whole range of physiological sweat rates. Specifically, the platform can be used for the development of sweat sensors for sedentary persons whose sweat rates are commonly lower than currently delivered by any other artificial skin platform.
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Affiliation(s)
- Emma J M Moonen
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Tanveer Ul Islam
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Sebastiaan van Kemenade
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
| | - Eduard Pelssers
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
- Philips Research, Royal Philips, High Tech Campus, 5656 AE Eindhoven, The Netherlands
| | - Jason Heikenfeld
- Novel Devices Laboratory, Biomedical Engineering Dept., Univ. of Cincinnati, Cincinnati, Ohio 45221, USA
| | - Jaap M J den Toonder
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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19
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Ayadh M, Guillermin A, Abellan MA, Bigouret A, Zahouani H. The assessment of natural human skin tension orientation and its variation according to age for two body areas: Forearm and thigh. J Mech Behav Biomed Mater 2023; 141:105798. [PMID: 36996528 DOI: 10.1016/j.jmbbm.2023.105798] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/23/2022] [Accepted: 03/23/2023] [Indexed: 03/30/2023]
Abstract
Human skin has a complex multilayer structure consisting of non-homogeneous, non-linear, viscoelastic and anisotropic materials subjected to in vivo natural pre-tension. This natural tension stems from networks of collagen and elastin fibers. The 3D organization of the collagen and elastin fibers underpins the multidirectional natural tensions in the skin volume while the state of the networks formed influences the surface topography of the skin. This topography depends on the area of the body and on the age of the person. Experiments reported in the literature have been performed ex vivo or on cadavers. By contrast, this work proposes the characterization of the anisotropic natural tension of the human skin in vivo. Experimental tests were performed on the forearms and thighs of 42 female volunteers representing two age groups [20 - 30] and [45-55] years old. Non-contact impact tests and skin-folding tests were conducted using devices developed at the LTDS (Lyon, France). The impact test generated a Rayleigh wave that spread in the skin. The speed of this wave was measured in 7 directions to study the anisotropy of the skin tension. The image of the skin relief at rest and during the skin folding test was reconstructed by optical confocal microscopy and provided the density of the skin lines printed on the outer surface of the skin. Skin folding test enables the clinician's manual procedure to be instrumented to identify tension lines i.e., Langer lines, for better healing during a surgical procedure. The main directions of natural skin tension deduced from the measured wave speed and the densities of skin lines were [40°-60°] for the forearm and [0°-20°] for the thigh, considering that the longitudinal axis of the body is situated at 90° and the transversal axis at 0°. This method shows the remarkable effect of age and body area on the mechanical behavior of human skin in vivo. The elastic properties and natural tension of the skin decrease with age. This decrease is greater in the directions orthogonal to the skin's tension lines, leading to the accentuation of the anisotropic behavior of the cutaneous tissue. The main direction of skin tension is highly dependent on the area of the body and is directed towards a preferred direction which corresponds to the main direction of skin tension.
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20
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Single and multi-dose drug loaded electrospun fiber mats for wound healing applications. J Drug Deliv Sci Technol 2023. [DOI: 10.1016/j.jddst.2023.104168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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21
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Parsa S, Wamsley C, Kim P, Kenkel J, Akgul Y. Use of Optical Coherence Tomography (OCT) in Assessment of Diabetic Skin Wound Characteristics and Blood Flow. J Foot Ankle Surg 2022; 62:407-412. [PMID: 36328918 DOI: 10.1053/j.jfas.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 09/23/2022] [Accepted: 10/01/2022] [Indexed: 11/11/2022]
Abstract
Optical coherence tomography allows for various measurements of skin but the utility of the device in determining properties of normal and wounded skin in diabetic patients is unknown. This single-site, non-randomized, observational study used an optical coherence tomography device to acquire skin images at 1305 nm, creating real-time image of 17 patient's skin and wounds 1 to 2 mm under the skin surface. Vertical B-scan, en-face and 3-D images were produced to calculate surface and dermal-epidermal junction roughness, the optical attenuation coefficient, a measure of light absorption and scattering, and blood flow metrics. In subjects with diabetes there was an increase in both the Ra (p < .02) and Rz (p < .001) of the wounded versus the control skin. In subjects without diabetes, there was an increase in both the Ra (p < .001) and Rz (p < .03) values of the wounded versus the control skin. At a depth of 0.6 mm across all subjects, there was an average decrease in blood flow of 63% from control to wounded skin. In subjects with diabetes, this decrease was 76%. In subjects without diabetes the decrease was 55%. The change in vasculature between control and wounded skin was associated with a p < .005. There was an increase in the Ra and Rz values and a decrease in blood flow between the wounded skin and control. The device determined a difference in the Ra and Rz values of both diabetic and healthy subjects' skin and a more pronounced decrease in blood flow in the wounds of patients with diabetes as opposed to those without.
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Affiliation(s)
- Shyon Parsa
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX
| | - Christine Wamsley
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX
| | - Paul Kim
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX.
| | - Jeffrey Kenkel
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX
| | - Yucel Akgul
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX
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22
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Chen K, Henn D, Sivaraj D, Bonham CA, Griffin M, Kussie HC, Padmanabhan J, Trotsyuk AA, Wan DC, Januszyk M, Longaker MT, Gurtner GC. Mechanical Strain Drives Myeloid Cell Differentiation Toward Proinflammatory Subpopulations. Adv Wound Care (New Rochelle) 2022; 11:466-478. [PMID: 34278820 PMCID: PMC9805866 DOI: 10.1089/wound.2021.0036] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 06/27/2021] [Indexed: 01/13/2023] Open
Abstract
Objective: After injury, humans and other mammals heal by forming fibrotic scar tissue with diminished function, and this healing process involves the dynamic interplay between resident cells within the skin and cells recruited from the circulation. Recent studies have provided mounting evidence that external mechanical forces stimulate intracellular signaling pathways to drive fibrotic processes. Innovation: While most studies have focused on studying mechanotransduction in fibroblasts, recent data suggest that mechanical stimulation may also shape the behavior of immune cells, referred to as "mechano-immunomodulation." However, the effect of mechanical strain on myeloid cell recruitment and differentiation remains poorly understood and has never been investigated at the single-cell level. Approach: In this study, we utilized a three-dimensional (3D) in vitro culture system that permits the precise manipulation of mechanical strain applied to cells. We cultured myeloid cells and used single-cell RNA-sequencing to interrogate the effects of strain on myeloid differentiation and transcriptional programming. Results: Our data indicate that myeloid cells are indeed mechanoresponsive, with mechanical stress influencing myeloid differentiation. Mechanical strain also upregulated a cascade of inflammatory chemokines, most notably from the Ccl family. Conclusion: Further understanding of how mechanical stress affects myeloid cells in conjunction with other cell types in the complicated, multicellular milieu of wound healing may lead to novel insights and therapies for the treatment of fibrosis.
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Affiliation(s)
- Kellen Chen
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Dominic Henn
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Dharshan Sivaraj
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Clark A. Bonham
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Michelle Griffin
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Hudson C. Kussie
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Jagannath Padmanabhan
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Artem A. Trotsyuk
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Derrick C. Wan
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Michael Januszyk
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Michael T. Longaker
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Palo Alto, California, USA
| | - Geoffrey C. Gurtner
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
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23
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Ullah H, Wahab MA, Will G, Karim MR, Pan T, Gao M, Lai D, Lin Y, Miraz MH. Recent Advances in Stretchable and Wearable Capacitive Electrophysiological Sensors for Long-Term Health Monitoring. BIOSENSORS 2022; 12:bios12080630. [PMID: 36005025 PMCID: PMC9406032 DOI: 10.3390/bios12080630] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/22/2022] [Accepted: 07/27/2022] [Indexed: 05/27/2023]
Abstract
Over the past several years, wearable electrophysiological sensors with stretchability have received significant research attention because of their capability to continuously monitor electrophysiological signals from the human body with minimal body motion artifacts, long-term tracking, and comfort for real-time health monitoring. Among the four different sensors, i.e., piezoresistive, piezoelectric, iontronic, and capacitive, capacitive sensors are the most advantageous owing to their reusability, high durability, device sterilization ability, and minimum leakage currents between the electrode and the body to reduce the health risk arising from any short circuit. This review focuses on the development of wearable, flexible capacitive sensors for monitoring electrophysiological conditions, including the electrode materials and configuration, the sensing mechanisms, and the fabrication strategies. In addition, several design strategies of flexible/stretchable electrodes, body-to-electrode signal transduction, and measurements have been critically evaluated. We have also highlighted the gaps and opportunities needed for enhancing the suitability and practical applicability of wearable capacitive sensors. Finally, the potential applications, research challenges, and future research directions on stretchable and wearable capacitive sensors are outlined in this review.
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Affiliation(s)
- Hadaate Ullah
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Md A. Wahab
- Institute for Advanced Study, Chengdu University, Chengdu 610106, China
- School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, George St Brisbane, GPO Box 2434, Brisbane, QLD 4001, Australia
| | - Geoffrey Will
- School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, George St Brisbane, GPO Box 2434, Brisbane, QLD 4001, Australia
| | - Mohammad R. Karim
- Center of Excellence for Research in Engineering Materials (CEREM), Deanship of Scientific Research (DSR), King Saud University, Riyadh 11421, Saudi Arabia
- K.A. CARE Energy Research and Innovation Center, Riyadh 11451, Saudi Arabia
| | - Taisong Pan
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Min Gao
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Dakun Lai
- Biomedical Imaging and Electrophysiology Laboratory, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yuan Lin
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
- Medico-Engineering Corporation on Applied Medicine Research Center, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Mahdi H. Miraz
- School of Computing and Data Science, Xiamen University Malaysia, Bandar Sunsuria, Sepang 43900, Malaysia
- School of Computing, Faculty of Arts, Science and Technology, Wrexham Glyndŵr University, Wrexham LL112AW, UK
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24
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de Bengy AF, Lamartine J, Sigaudo-Roussel D, Fromy B. Newborn and elderly skin: two fragile skins at higher risk of pressure injury. Biol Rev Camb Philos Soc 2022; 97:874-895. [PMID: 34913582 DOI: 10.1111/brv.12827] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023]
Abstract
Skin is a key organ maintaining internal homeostasis by performing many functions such as water loss prevention, body temperature regulation and protection from noxious substance absorption, microorganism intrusion and physical trauma. Skin ageing has been well studied and it is well known that physiological changes in the elderly result in higher skin fragility favouring the onset of skin diseases. For example, prolonged and/or high-intensity pressure may suppress local blood flow more easily, disturbing cell metabolism and inducing pressure injury (PI) formation. Pressure injuries (PIs) represent a significant problem worldwide and their prevalence remains too high. A higher PI prevalence is correlated with an elderly population. Newborn skin evolution has been less studied, but some data also report a higher PI prevalence in this population compared to older children, and several authors also consider this skin as physiologically fragile. In this review, we compare the characteristics of newborn and elderly skin in order to determine common features that may explain their fragility, especially regarding PI risk. We show that, despite differences in appearance, they share many common features leading to higher fragility to shear and pressure forces, not only at the structural level but also at the cellular and molecular level and in terms of physiology. Both newborn and elderly skin have: (i) a thinner epidermis; (ii) a thinner dermis containing a less-resistant collagen network, a higher collagen III:collagen I ratio and less elastin; (iii) a flatter dermal-epidermal junction (DEJ) with lower anchoring systems; and (iv) a thinner hypodermis, resulting in lower mechanical resistance to skin damage when pressure or shear forces are applied. At the molecular level, reduced expression of transforming growth factor β (TGFβ) and its receptor TGFβ receptor II (TβRII) is involved in the decreased production and/or increased degradation of various dermal extracellular matrix (ECM) components. Epidermal fragility also involves a higher skin pH which decreases the activity of key enzymes inducing ceramide deficiency and reduced barrier protection. This seems to be correlated with higher PI prevalence in some situations. Some data also suggest that stratum corneum (SC) dryness, which may disturb cell metabolism, also increases the risk of PI formation. Besides this structural fragility, several skin functions are also less efficient. Low applied pressures induce skin vessel vasodilation via a mechanism called pressure-induced vasodilation (PIV). Individuals lacking a normal PIV response show an early decrease in cutaneous blood flow in response to the application of very low pressures, reflecting vascular fragility of the skin that increases the risk of ulceration. Due to changes in endothelial function, skin PIV ability decreases during skin ageing, putting it at higher risk of PI formation. In newborns, some data lead us to hypothesize that the nitric oxide (NO) pathway is not fully functional at birth, which may partly explain the higher risk of PI formation in newborns. In the elderly, a lower PIV ability results from impaired functionality of skin innervation, in particular that of C-fibres which are involved in both touch and pain sensation and the PIV mechanism. In newborns, skin sensitivity differs from adults due to nerve system immaturity, but the role of this in PIV remains to be determined.
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Affiliation(s)
| | - Jérôme Lamartine
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, LBTI UMR5305, 7 Passage du Vercors, Lyon Cedex 7, F- 69367, France
| | - Dominique Sigaudo-Roussel
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, LBTI UMR5305, 7 Passage du Vercors, Lyon Cedex 7, F- 69367, France
| | - Bérengère Fromy
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, LBTI UMR5305, 7 Passage du Vercors, Lyon Cedex 7, F- 69367, France
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25
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Chen K, Henn D, Januszyk M, Barrera JA, Noishiki C, Bonham CA, Griffin M, Tevlin R, Carlomagno T, Shannon T, Fehlmann T, Trotsyuk AA, Padmanabhan J, Sivaraj D, Perrault DP, Zamaleeva AI, Mays CJ, Greco AH, Kwon SH, Leeolou MC, Huskins SL, Steele SR, Fischer KS, Kussie HC, Mittal S, Mermin-Bunnell AM, Diaz Deleon NM, Lavin C, Keller A, Longaker MT, Gurtner GC. Disrupting mechanotransduction decreases fibrosis and contracture in split-thickness skin grafting. Sci Transl Med 2022; 14:eabj9152. [PMID: 35584231 DOI: 10.1126/scitranslmed.abj9152] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Burns and other traumatic injuries represent a substantial biomedical burden. The current standard of care for deep injuries is autologous split-thickness skin grafting (STSG), which frequently results in contractures, abnormal pigmentation, and loss of biomechanical function. Currently, there are no effective therapies that can prevent fibrosis and contracture after STSG. Here, we have developed a clinically relevant porcine model of STSG and comprehensively characterized porcine cell populations involved in healing with single-cell resolution. We identified an up-regulation of proinflammatory and mechanotransduction signaling pathways in standard STSGs. Blocking mechanotransduction with a small-molecule focal adhesion kinase (FAK) inhibitor promoted healing, reduced contracture, mitigated scar formation, restored collagen architecture, and ultimately improved graft biomechanical properties. Acute mechanotransduction blockade up-regulated myeloid CXCL10-mediated anti-inflammation with decreased CXCL14-mediated myeloid and fibroblast recruitment. At later time points, mechanical signaling shifted fibroblasts toward profibrotic differentiation fates, and disruption of mechanotransduction modulated mesenchymal fibroblast differentiation states to block those responses, instead driving fibroblasts toward proregenerative, adipogenic states similar to unwounded skin. We then confirmed these two diverging fibroblast transcriptional trajectories in human skin, human scar, and a three-dimensional organotypic model of human skin. Together, pharmacological blockade of mechanotransduction markedly improved large animal healing after STSG by promoting both early, anti-inflammatory and late, regenerative transcriptional programs, resulting in healed tissue similar to unwounded skin. FAK inhibition could therefore supplement the current standard of care for traumatic and burn injuries.
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Affiliation(s)
- Kellen Chen
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Surgery, University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Dominic Henn
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael Januszyk
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Janos A Barrera
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Chikage Noishiki
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Clark A Bonham
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michelle Griffin
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ruth Tevlin
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Theresa Carlomagno
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tara Shannon
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tobias Fehlmann
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | - Artem A Trotsyuk
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jagannath Padmanabhan
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Dharshan Sivaraj
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David P Perrault
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alsu I Zamaleeva
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Chyna J Mays
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Autumn H Greco
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sun Hyung Kwon
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Melissa C Leeolou
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Savana L Huskins
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sydney R Steele
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Katharina S Fischer
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hudson C Kussie
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Smiti Mittal
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alana M Mermin-Bunnell
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nestor M Diaz Deleon
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Christopher Lavin
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Andreas Keller
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany.,Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Michael T Longaker
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Geoffrey C Gurtner
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Surgery, University of Arizona College of Medicine, Tucson, AZ 85724, USA
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26
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Qin K, Pereira RFP, Coradin T, de Zea Bermudez V, Fernandes FM. Biomimetic Silk Macroporous Materials for Drug Delivery Obtained via Ice-Templating. ACS APPLIED BIO MATERIALS 2022; 5:2556-2566. [PMID: 35537179 DOI: 10.1021/acsabm.2c00020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Silk from Bombyx mori is one of the most exciting materials in nature. The apparently simple arrangement of its two major components─two parallel filaments of silk fibroin (SF) coated by a common sericin (SS) sheath─provides a combination of mechanical and surface properties that can protect the moth during its most vulnerable phase, the pupal stage. Here, we recapitulate the topology of native silk fibers but shape them into three-dimensional porous constructs using an unprecedented design strategy. We demonstrate, for the first time, the potential of these macroporous silk foams as dermal patches for wound protection and for the controlled delivery of Rifamycin (Rif), a model antibiotic. The method implies (i) removing SS from silk fibers; (ii) shaping SF solutions into macroporous foams via ice-templating; (iii) stabilizing the SF macroporous foam in a methanolic solution of Rif; and (iv) coating Rif-loaded SF foams with a SS sheath. The resulting SS@SF foams exhibit water wicking capacity and accommodate up to ∼20% deformation without detaching from a skin model. The antibacterial behavior of Rif-loaded SS@SF foams against Staphylococcus aureus on agar plates outperforms that of SF foams (>1 week and 4 days, respectively). The reassembly of natural materials as macroporous foams─illustrated here for the reconstruction of silk-based materials─can be extended to other multicomponent natural materials and may play an important role in applications where controlled release of molecules and fluid transport are pivotal.
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Affiliation(s)
- Kankan Qin
- Sorbonne Université, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, F-75005 Paris, France
| | - Rui F P Pereira
- Chemistry Center and Chemistry Department, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Thibaud Coradin
- Sorbonne Université, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, F-75005 Paris, France
| | - Verónica de Zea Bermudez
- Chemistry Department and CQ-VR, University of Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real, Portugal
| | - Francisco M Fernandes
- Sorbonne Université, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, F-75005 Paris, France
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27
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Béduer A, Genta M, Kunz N, Verheyen C, Martins M, Brefie-Guth J, Braschler T. Design of an elastic porous injectable biomaterial for tissue regeneration and volume retention. Acta Biomater 2022; 142:73-84. [PMID: 35101581 DOI: 10.1016/j.actbio.2022.01.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 01/01/2022] [Accepted: 01/24/2022] [Indexed: 11/01/2022]
Abstract
Soft tissue reconstruction currently relies on two main approaches, one involving the implantation of external biomaterials and the second one exploiting surgical autologous tissue displacement. While both methods have different advantages and disadvantages, successful long-term solutions for soft tissue repair are still limited. Specifically, volume retention over time and local tissue regeneration are the main challenges in the field. In this study the performance of a recently developed elastic porous injectable (EPI) biomaterial based on crosslinked carboxymethylcellulose is analyzed. Nearly quantitative volumetric stability, with over 90% volume retention at 6 months, is observed, and the pore space of the material is effectively colonized with autologous fibrovascular tissue. A comparative analysis with hyaluronic acid and collagen-based clinical reference materials is also performed. Mechanical stability, evidenced by a low-strain elastic storage modulus (G') approaching 1kPa and a yield strain of several tens of percent, is required for volume retention in-vivo. Macroporosity, along with in-vivo persistence of at least several months, is instead needed for successful host tissue colonization. This study demonstrates the importance of understanding material design criteria and defines the biomaterial requirements for volume retention and tissue colonization in soft tissue regeneration. STATEMENT OF SIGNIFICANCE: We present the design of an elastic, porous, injectable (EPI) scaffold suspension capable of inducing a precisely defined, stable volume of autologous connective tissue in situ. It combines volume stability and vascularized tissue induction capacity known from bulk scaffolds with the ease of injection in shear yielding materials. By comparative study with a series of clinically established biomaterials including a wound healing matrix and dermal fillers, we establish design rules regarding rheological and compressive mechanical properties as well as degradation characteristics that rationally underpin the volume stability and tissue induction in a high-performance biomaterial. These design rules should allow to streamline the development of new colonizable injectables.
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28
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Mogera U, Guo H, Namkoong M, Rahman MS, Nguyen T, Tian L. Wearable plasmonic paper-based microfluidics for continuous sweat analysis. SCIENCE ADVANCES 2022; 8:eabn1736. [PMID: 35319971 PMCID: PMC8942375 DOI: 10.1126/sciadv.abn1736] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/31/2022] [Indexed: 05/24/2023]
Abstract
Wearable sweat sensors have the potential to provide clinically meaningful information associated with the health and disease states of individuals. Current sensors mainly rely on enzymes and antibodies as biorecognition elements to achieve specific quantification of metabolite and stress biomarkers in sweat. However, enzymes and antibodies are prone to degrade over time, compromising the sensor performance. Here, we introduce a wearable plasmonic paper-based microfluidic system for continuous and simultaneous quantitative analysis of sweat loss, sweat rate, and metabolites in sweat. Plasmonic sensors based on label-free surface-enhanced Raman spectroscopy (SERS) can provide chemical "fingerprint" information for analyte identification. We demonstrate the sensitive detection and quantification of uric acid in sweat at physiological and pathological concentrations. The well-defined flow characteristics of paper microfluidic devices enable accurate quantification of sweat loss and sweat rate. The wearable plasmonic device is soft, flexible, and stretchable, which can robustly interface with the skin without inducing chemical or physical irritation.
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29
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Teng ZL, Yang XG, Geng X, Gu YJ, Huang R, Chen WM, Wang C, Chen L, Zhang C, Helili M, Huang JZ, Wang X, Ma X. Effect of loading history on material properties of human heel pad: an in-vivo pilot investigation during gait. BMC Musculoskelet Disord 2022; 23:254. [PMID: 35292004 PMCID: PMC8925218 DOI: 10.1186/s12891-022-05197-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 03/06/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study was aimed to develop a novel dynamic measurement technique for testing the material properties and investigating the effect of continuous compression load on the structural and mechanical properties of human heel pad during actual gait. METHODS The dual fluoroscopic imaging system (DFIS) and dynamic foot-ground contact pressure-test plate were used for measuring the material properties, including primary thickness, peak strain, peak stress, elastic modulus, viscous modulus and energy dissipation rate (EDR), both at time zero and following continuous loading. Ten healthy pilot subjects, aged from 23 to 72 (average: 46.5 ± 17.6), were enrolled. A "three-step gait cycle" is performed for all subjects, with the second step striking at a marked position on the force plate with the heel to maintain the location of the tested foot to be in the view of fluoroscopes. The subjects were measured at both relaxed (time-zero group) and fatigue (continuous-loading group) statuses, and the left and right heels were measured using the identical procedures. RESULTS The peak strain, peak stress, elastic modulus, and EDR are similar before and after continuous load, while the viscous modulus was significantly decreased (median: 43.9 vs. 20.37 kPa•s; p < 0.001) as well as primary thicknesses (median: 15.99 vs. 15.72 mm; p < 0.001). Age is demonstrated to be moderately correlated with the primary thicknesses both at time zero (R = -0.507) and following continuous load (R = -0.607). The peak stress was significantly correlated with the elastic modulus before (R = 0.741) and after continuous load (R = 0.802). The peak strain was correlated with the elastic modulus before (R = -0.765) and after continuous load (R = -0.801). The correlations between the viscous modulus and peak stress/ peak strain are similar to above(R = 0.643, 0.577, - 0.586 and - 0.717 respectively). The viscous modulus is positively correlated with the elastic modulus before (R = 0.821) and after continuous load (R = 0.784). CONCLUSIONS By using dynamic fluoroscopy combined with the plantar pressure plate, the in vivo viscoelastic properties and other data of the heel pad in the actual gait can be obtained. Age was negatively correlated with the primary thickness of heel pad and peak strain, and was positively correlated with viscous modulus. Repetitive loading could decrease the primary thickness of heel pad and viscous modulus.
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Affiliation(s)
- Zhao-Lin Teng
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Xiong-Gang Yang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Xiang Geng
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China.
| | - Yan-Jie Gu
- Academy for Engineering & Technology, Fudan University, No.220 Handan Road, Shanghai, 200438, China
| | - Ran Huang
- Academy for Engineering & Technology, Fudan University, No.220 Handan Road, Shanghai, 200438, China
| | - Wen-Ming Chen
- Academy for Engineering & Technology, Fudan University, No.220 Handan Road, Shanghai, 200438, China
| | - Chen Wang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Li Chen
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Chao Zhang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Maimaitirexiati Helili
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Jia-Zhang Huang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Xu Wang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China
| | - Xin Ma
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, No.12 Wulumuqi Middle Road, Shanghai, 200040, China.
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Effect of seasonal change on the biomechanical and physical properties of the human skin. J Mech Behav Biomed Mater 2022; 127:105058. [DOI: 10.1016/j.jmbbm.2021.105058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 12/06/2021] [Accepted: 12/19/2021] [Indexed: 11/17/2022]
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A new device for the combined measurement of friction and through-thickness deformation on ex vivo skin samples. J Mech Behav Biomed Mater 2022; 130:105141. [PMID: 35318168 DOI: 10.1016/j.jmbbm.2022.105141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/08/2022] [Accepted: 02/19/2022] [Indexed: 11/20/2022]
Abstract
Skin irritation is a common phenomenon that becomes a real concern when caused by the use of medical devices. Because the materials used for the design of these devices are usually carefully selected for chemical compatibility with the skin, it is reasonable to assume that the irritations result from the mechanical interaction between the devices and the skin. The aim of this work was to develop a new device to study both the shear strains in the layers of the skin, using Digital Image Correlation (DIC), and the friction behaviour of ex vivo skin interacting with objects. Pig skin samples with various surface preparations were tested in friction experiments involving different contacting materials encountered in the conception of medical devices. The measure of the static and dynamic coefficients of friction as well as the length of adhesion has highlighted the great influence of skin surface conditioning on friction properties. Strain maps obtained through DIC provided insights into the impact of friction and adhesion effects on shear strain distribution in the skin as a function of depth beneath its surface.
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Chen Y, Gao Q, Li J, Mao F, Tang R, Jiang H. Activation of Topological Defects Induces a Brittle-to-Ductile Transition in Epithelial Monolayers. PHYSICAL REVIEW LETTERS 2022; 128:018101. [PMID: 35061486 DOI: 10.1103/physrevlett.128.018101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Epithelial monolayers are subjected to various mechanical forces, such as stretching, shearing, and compression. Thus, its mechanical response to external loadings is essential for its biological functions. However, the mechanism of the fracture failure of the epithelial monolayer remains poorly understood. Here, by introducing a new type of topological transition, i.e., detach transition or T4 transition, we develop a modified cellular vertex model to investigate the rupture of the cell monolayer. Interestingly, we find a brittle-to-ductile transition in epithelial monolayers, which is controlled by the mechanical properties of single cells and cell-cell contacts. We reveal that the external loadings can activate cell rearrangement in ductile cell monolayers. The plastic deformation results from the nucleation and propagation of "pentagon-heptagon defects" in analogy with the topological defects commonly seen in 2D materials. By using a simplified four-cell model, we further demonstrate that the brittle-to-ductile transition is induced by the competition between cell rearrangement and cell detachment. Our work provides a new theoretical framework to study the rupture of living tissues and may have important implications for many other biological processes, such as wound healing and tissue morphogenesis.
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Affiliation(s)
- Yixia Chen
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qigan Gao
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jingchen Li
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fangtao Mao
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ruowen Tang
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hongyuan Jiang
- Hefei National Laboratory for Physical Science at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, CAS Center for Excellence in Complex System Mechanics, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China
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Yang XG, Teng ZL, Zhang ZM, Wang K, Huang R, Chen WM, Wang C, Chen L, Zhang C, Huang JZ, Wang X, Ma X, Geng X. Comparison of material properties of heel pad between adults with and without type 2 diabetes history: An in-vivo investigation during gait. Front Endocrinol (Lausanne) 2022; 13:894383. [PMID: 36060939 PMCID: PMC9428762 DOI: 10.3389/fendo.2022.894383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE This study was aimed to compare the material properties of heel pad between diabetes patients and healthy adults, and investigate the impact of compressive loading history and length of diabetes course on the material properties of heel pad. METHODS The dual fluoroscopic imaging system (DFIS) and dynamic foot-ground contact pressure-test plate were used for measuring the material properties, including primary thickness, peak strain, peak stress, stiffness, viscous modulus and energy dissipation ratio (EDR), both at time zero and following continuous loading. Material properties between healthy adults and DM patients were compared both at time zero and following continuous weight bearing. After then, comparison between time-zero material properties and properties following continuous loading was performed to identify the loading history-dependent biomechanical behaviour of heel pad. Subgroup-based sensitivity analysis was then conducted to investigate the diabetes course (<10 years vs. ≥10 years) on the material properties of heel pad. RESULTS Ten type II DM subjects (20 legs), aged from 59 to 73 (average: 67.8 ± 4.9), and 10 age-matched healthy adults (20 legs), aged from 59 to 72 (average: 64.4 ± 3.4), were enrolled. Diabetes history was demonstrated to be associated with significantly lower primary thickness (t=3.18, p=0.003**), higher peak strain (t=2.41, p=0.021*), lower stiffness (w=283, p=0.024*) and lower viscous modulus (w=331, p<0.001***) at time zero, and significantly lower primary thickness (t=3.30, p=0.002**), higher peak strain (w=120, p=0.031*) and lower viscous modulus (t=3.42, p=0.002**) following continuous loading. The continuous loading was found to be associated with significantly lower primary thickness (paired-w=204, p<0.001***) and viscous modulus (paired-t=5.45, p<0.001***) in healthy adults, and significantly lower primary thickness (paired-w=206, p<0.001***) and viscous modulus (paired-t=7.47, p<0.001***) in diabetes group. No any significant difference was found when conducting the subgroup analysis based on length of diabetes course (<10 years vs. ≥10 years), but the regression analysis showed that the length of diabetes history was positively associated with the peak strain, at time zero (r=0.506, p<0.050) and following continuous loading (r=0.584, p<0.010). CONCLUSIONS Diabetes patients were found to be associated with decreased primary thickness and viscous modulus, and increased peak strain, which may contribute to the vulnerability of heel pad to injury and ulceration. Pre-compression history-dependent behaviour is observable in soft tissue of heel pad, with lowered primary thickness and viscous modulus.
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Affiliation(s)
- Xiong-gang Yang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhao-lin Teng
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhen-ming Zhang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Kan Wang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Ran Huang
- Academy for Engineering & Technology, Fudan University, Shanghai, China
| | - Wen-ming Chen
- Academy for Engineering & Technology, Fudan University, Shanghai, China
| | - Chen Wang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Li Chen
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Chao Zhang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jia-zhang Huang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Xu Wang
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Xin Ma
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Xiang Geng, ; Xin Ma,
| | - Xiang Geng
- Department of Orthopedic Surgery, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Xiang Geng, ; Xin Ma,
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Xu W, Chen S, Yao M, Lu Q. Mechanical Behavior of Biomimetic Oriented Cell Sheets from a Perspective of Living Materials. Biomater Sci 2022; 10:3099-3109. [DOI: 10.1039/d2bm00302c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
When compared to random cell organization, cell sheets with well-organized cell orientation are similar to natural tissues exhibiting better mechanical strength. Furthermore, as living materials, the mechanical strength of cell...
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36
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Kao AR, Xu C, Gerling GJ. Using Digital Image Correlation to Quantify Skin Deformation With Von Frey Monofilaments. IEEE TRANSACTIONS ON HAPTICS 2022; 15:26-31. [PMID: 34951855 PMCID: PMC9006180 DOI: 10.1109/toh.2021.3138350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Thin von Frey monofilaments are a clinical tool used worldwide to assess touch deficits. One's ability to perceive touch with low-force monofilaments (0.008 - 0.07 g) establishes an absolute threshold and thereby the extent of impairment. While individual monofilaments bend at defined forces, there are no empirical measurements of the skin surface's response. In this work, we measure skin surface deformation at light-touch perceptual limits, by adopting an imaging approach using 3D digital image correlation (DIC). Generating point cloud data from three cameras surveilling the index finger pad, we reassemble and stitch together multiple 3D surfaces. Then, in response to each monofilament's indentation over time, we quantify strain across the skin surface, radial deformation emanating from the contact point, penetration depth into the surface, and area between 2D cross-sections. The results show that the monofilaments create distinct states of skin deformation, which align closely with just noticeable percepts at absolute detection and discrimination thresholds, even amidst variance between individuals and trials. In particular, the resolution of the DIC imaging approach captures sufficient differences in skin deformation at threshold, offering promise in understanding the skin's role in perception.
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Zhong J, Chen S, Zhao Y, Yin J, Wang Y, Gong H, Zhang X, Wang J, Wu Y, Huang W. Shape Optimization of Costal Cartilage Framework Fabrication Based on Finite Element Analysis for Reducing Incidence of Auricular Reconstruction Complications. Front Bioeng Biotechnol 2021; 9:766599. [PMID: 34966727 PMCID: PMC8711272 DOI: 10.3389/fbioe.2021.766599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022] Open
Abstract
Skin necrosis is the most common complication in total auricular reconstruction, which is mainly induced by vascular compromise and local stress concentration of the overlying skin. Previous studies generally emphasized the increase in the skin flap blood supply, while few reports considered the mechanical factors. However, skin injury is inevitable due to uneasily altered loads generated by the intraoperative continuous negative suction and uneven cartilage framework structure. Herein, this study aims to attain the stable design protocol of the ear cartilage framework to decrease mechanical damage and the incidence of skin necrosis. Finite element analysis was initially utilized to simulate the reconstructive process while the shape optimization technique was then adopted to optimize the three-pretested shape of the hollows inside the scapha and fossa triangularis under negative suction pressure. Finally, the optimal results would be output automatically to meet clinical requirement. Guided by the results of FE-based shape optimization, the optimum framework with the smallest holes inside the scapha and fossa triangularis was derived. Subsequent finite element analysis results also demonstrated the displacement and stress of the post-optimized model were declined 64.9 and 40.1%, respectively. The following clinical study was performed to reveal that this new design reported lower rates of skin necrosis decrease to 5.08%, as well as the cartilage disclosure decreased sharply from 14.2 to 3.39% compared to the conventional method. Both the biomechanical analysis and the clinical study confirmed that the novel design framework could effectively reduce the rates of skin necrosis, which shows important clinical significance for protecting against skin necrosis.
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Affiliation(s)
- Jing Zhong
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Suijun Chen
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanyan Zhao
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Junfeiyang Yin
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yilin Wang
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Haihuan Gong
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xueyuan Zhang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jiejie Wang
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yaobin Wu
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Wenhua Huang
- Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Guangdong Provincial Key Laboratory of Medical Biomechanics, National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
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Chaturvedi P, Worsley PR, Zanelli G, Kroon W, Bader DL. Quantifying skin sensitivity caused by mechanical insults: A review. Skin Res Technol 2021; 28:187-199. [PMID: 34708455 PMCID: PMC9298205 DOI: 10.1111/srt.13104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/21/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Skin sensitivity (SS) is a commonly occurring response to a range of stimuli, including environmental conditions (e.g., sun exposure), chemical irritants (e.g., soaps and cosmetics), and mechanical forces (e.g., while shaving). From both industry and academia, many efforts have been taken to quantify the characteristics of SS in a standardised manner, but the study is hindered by the lack of an objective definition. METHODS A review of the scientific literature regarding different parameters attributed to the loss of skin integrity and linked with exhibition of SS was conducted. Articles included were screened for mechanical stimulation of the skin, with objective quantification of tissue responses using biophysical or imaging techniques. Additionally, studies where cohorts of SS and non-SS individuals were reported have been critiqued. RESULTS The findings identified that the structure and function of the stratum corneum and its effective barrier properties are closely associated with SS. Thus, an array of skin tissue responses has been selected for characterization of SS due to mechanical stimuli, including: transepidermal water loss, hydration, redness, temperature, and sebum index. Additionally, certain imaging tools allow quantification of the superficial skin layers, providing structural characteristics underlying SS. CONCLUSION This review proposes a multimodal approach for identification of SS, providing a means to characterise skin tissue responses objectively. Optical coherence tomography (OCT) has been suggested as a suitable tool for dermatological research with clinical applications. Such an approach would enhance the knowledge underlying the multifactorial nature of SS and aid the development of personalised solutions in medical and consumer devices.
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Affiliation(s)
- Pakhi Chaturvedi
- Philips Consumer Lifestyle B.V., Drachten, The Netherlands.,School of Health Sciences, University of Southampton, Southampton, UK
| | - Peter R Worsley
- School of Health Sciences, University of Southampton, Southampton, UK
| | - Giulia Zanelli
- Philips Consumer Lifestyle B.V., Drachten, The Netherlands
| | - Wilco Kroon
- Philips Consumer Lifestyle B.V., Drachten, The Netherlands
| | - Dan L Bader
- School of Health Sciences, University of Southampton, Southampton, UK
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Béduer A, Bonini F, Verheyen CA, Genta M, Martins M, Brefie-Guth J, Tratwal J, Filippova A, Burch P, Naveiras O, Braschler T. An Injectable Meta-Biomaterial: From Design and Simulation to In Vivo Shaping and Tissue Induction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102350. [PMID: 34449109 DOI: 10.1002/adma.202102350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/14/2021] [Indexed: 06/13/2023]
Abstract
A novel type of injectable biomaterial with an elastic softening transition is described. The material enables in vivo shaping, followed by induction of 3D stable vascularized tissue. The synthesis of the injectable meta-biomaterial is instructed by extensive numerical simulation as a suspension of irregularly fragmented, highly porous sponge-like microgels. The irregular particle shape dramatically enhances yield strain for in vivo stability against deformation. Porosity of the particles, along with friction between internal surfaces, provides the elastic softening transition. This emergent metamaterial property enables the material to reversibly change stiffness during deformation, allowing native tissue properties to be matched over a wide range of deformation amplitudes. After subcutaneous injection in mice, predetermined shapes can be sculpted manually. The 3D shape is maintained during excellent host tissue integration, with induction of vascular connective tissue that persists to the end of one-year follow-up. The geometrical design is compatible with many hydrogel materials, including cell-adhesion motives for cell transplantation. The injectable meta-biomaterial therefore provides new perspectives in soft tissue engineering and regenerative medicine.
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Affiliation(s)
- Amélie Béduer
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), LMIS4. BM, Station 17, Lausanne, CH-1015, Switzerland
| | - Fabien Bonini
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
| | - Connor A Verheyen
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), LMIS4. BM, Station 17, Lausanne, CH-1015, Switzerland
| | - Martina Genta
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), LMIS4. BM, Station 17, Lausanne, CH-1015, Switzerland
| | - Mariana Martins
- Volumina-Medical SA, Route de la Corniche 5, Epalinges, CH-1066, Switzerland
| | - Joé Brefie-Guth
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
| | - Josefine Tratwal
- Department of Biomedical Sciences, Laboratory of Regenerative Hematopoiesis, University of Lausanne, Rue du Bugnon 27, Lausanne, CH-1011, Switzerland
| | - Aleksandra Filippova
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
| | - Patrick Burch
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), LMIS4. BM, Station 17, Lausanne, CH-1015, Switzerland
- Volumina-Medical SA, Route de la Corniche 5, Epalinges, CH-1066, Switzerland
| | - Olaia Naveiras
- Department of Biomedical Sciences, Laboratory of Regenerative Hematopoiesis, University of Lausanne, Rue du Bugnon 27, Lausanne, CH-1011, Switzerland
- CHUV, Hematology Service, Department of Oncology, Rue du Bugnon 46, Lausanne, CH-1011, Switzerland
| | - Thomas Braschler
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
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Montazerian H, Baidya A, Haghniaz R, Davoodi E, Ahadian S, Annabi N, Khademhosseini A, Weiss PS. Stretchable and Bioadhesive Gelatin Methacryloyl-Based Hydrogels Enabled by in Situ Dopamine Polymerization. ACS APPLIED MATERIALS & INTERFACES 2021; 13:40290-40301. [PMID: 34410697 DOI: 10.1021/acsami.1c10048] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Hydrogel patches with high toughness, stretchability, and adhesive properties are critical to healthcare applications including wound dressings and wearable devices. Gelatin methacryloyl (GelMA) provides a highly biocompatible and accessible hydrogel platform. However, low tissue adhesion and poor mechanical properties of cross-linked GelMA patches (i.e., brittleness and low stretchability) have been major obstacles to their application for sealing and repair of wounds. Here, we show that adding dopamine (DA) moieties in larger quantities than those of conjugated counterparts to the GelMA prepolymer solution followed by alkaline DA oxidation could result in robust mechanical and adhesive properties in GelMA-based hydrogels. In this way, cross-linked patches with ∼140% stretchability and ∼19 000 J/m3 toughness, which correspond to ∼5.7 and ∼3.3× improvement, respectively, compared to that of GelMA controls, were obtained. The DA oxidization in the prepolymer solution was found to play an important role in activating adhesive properties of cross-linked GelMA patches (∼4.0 and ∼6.9× increase in adhesion force under tensile and shear modes, respectively) due to the presence of reactive oxidized quinone species. We further conducted a parametric study on the factors such as UV light parameters, the photoinitiator type (i.e., lithium phenyl-2,4,6-trimethylbenzoylphosphinate, LAP, versus 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, Irgacure 2959), and alkaline DA oxidation to tune the cross-linking density and thereby hydrogel compliance for better adhesive properties. The superior adhesion performance of the resulting hydrogel along with in vitro cytocompatibility demonstrated its potential for use in skin-attachable substrates.
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Affiliation(s)
- Hossein Montazerian
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Terasaki Institute for Biomedical Innovation, Los Angeles, California 90024, United States
| | - Avijit Baidya
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Reihaneh Haghniaz
- Terasaki Institute for Biomedical Innovation, Los Angeles, California 90024, United States
| | - Elham Davoodi
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Terasaki Institute for Biomedical Innovation, Los Angeles, California 90024, United States
- Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Samad Ahadian
- Terasaki Institute for Biomedical Innovation, Los Angeles, California 90024, United States
| | - Nasim Annabi
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Ali Khademhosseini
- Terasaki Institute for Biomedical Innovation, Los Angeles, California 90024, United States
| | - Paul S Weiss
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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Jo YK, Heo SJ, Peredo AP, Mauck RL, Dodge GR, Lee D. Stretch-responsive adhesive microcapsules for strain-regulated antibiotic release from fabric wound dressings. Biomater Sci 2021; 9:5136-5143. [PMID: 34223592 DOI: 10.1039/d1bm00628b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial infection of a wound is a major complication that can significantly delay proper healing and even necessitate surgical debridement. Conventional non-woven fabric dressings, including gauzes, bandages and cotton wools, often fail in treating wound infections in a timely manner due to their passive release mechanism of antibiotics. Here, we propose adhesive mechanically-activated microcapsules (MAMCs) capable of strongly adhering to a fibrous matrix to achieve a self-regulated release of antibiotics upon uniaxial stretching of non-woven fabric dressings. To achieve this, a uniform population of polydopamine (PDA)-coated MAMCs (PDA-MAMCs) are prepared using a microfluidics technique and subsequent oxidative dopamine polymerization. The PDA-MAMC allows for robust mechano-activation within the fibrous network through high retention and effective transmission of mechanical force under stretching. By validating the potential of a PDA-MAMCs-laden gauze to release antibiotics in a tensile strain-dependent manner, we demonstrate that PDA-MAMCs can be successfully incorporated into a woven material and create a smart wound dressing for control of bacterial infections. This new mechano-activatable delivery approach will open up a new avenue for a stretch-triggered, on-demand release of therapeutic cargos in skin-mountable or wearable biomedical devices.
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Affiliation(s)
- Yun Kee Jo
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Moreira Lana G, Sorg K, Wenzel GI, Hecker D, Hensel R, Schick B, Kruttwig K, Arzt E. Self‐Adhesive Silicone Microstructures for the Treatment of Tympanic Membrane Perforations. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Gabriela Moreira Lana
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
- Department of Materials Science and Engineering Saarland University Campus D2 2 Saarbrücken 66123 Germany
| | - Katharina Sorg
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Gentiana Ioana Wenzel
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Dietmar Hecker
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - René Hensel
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Klaus Kruttwig
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
| | - Eduard Arzt
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
- Department of Materials Science and Engineering Saarland University Campus D2 2 Saarbrücken 66123 Germany
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Characterization of the strain-rate-dependent mechanical response of single cell-cell junctions. Proc Natl Acad Sci U S A 2021; 118:2019347118. [PMID: 33531347 DOI: 10.1073/pnas.2019347118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cell-cell adhesions are often subjected to mechanical strains of different rates and magnitudes in normal tissue function. However, the rate-dependent mechanical behavior of individual cell-cell adhesions has not been fully characterized due to the lack of proper experimental techniques and therefore remains elusive. This is particularly true under large strain conditions, which may potentially lead to cell-cell adhesion dissociation and ultimately tissue fracture. In this study, we designed and fabricated a single-cell adhesion micro tensile tester (SCAµTT) using two-photon polymerization and performed displacement-controlled tensile tests of individual pairs of adherent epithelial cells with a mature cell-cell adhesion. Straining the cytoskeleton-cell adhesion complex system reveals a passive shear-thinning viscoelastic behavior and a rate-dependent active stress-relaxation mechanism mediated by cytoskeleton growth. Under low strain rates, stress relaxation mediated by the cytoskeleton can effectively relax junctional stress buildup and prevent adhesion bond rupture. Cadherin bond dissociation also exhibits rate-dependent strengthening, in which increased strain rate results in elevated stress levels at which cadherin bonds fail. This bond dissociation becomes a synchronized catastrophic event that leads to junction fracture at high strain rates. Even at high strain rates, a single cell-cell junction displays a remarkable tensile strength to sustain a strain as much as 200% before complete junction rupture. Collectively, the platform and the biophysical understandings in this study are expected to build a foundation for the mechanistic investigation of the adaptive viscoelasticity of the cell-cell junction.
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Persons AK, Ball JE, Freeman C, Macias DM, Simpson CL, Smith BK, Burch V. RF. Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4070. [PMID: 34361264 PMCID: PMC8347841 DOI: 10.3390/ma14154070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/09/2021] [Accepted: 07/16/2021] [Indexed: 12/23/2022]
Abstract
Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from "bench to bedside", fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.
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Affiliation(s)
- Andrea Karen Persons
- Department of Agricultural and Biological Engineering, Mississippi State University, 130 Creelman Street, Starkville, MS 39762, USA; (A.K.P.); (C.L.S.)
- Human Factors and Athlete Engineering, Center for Advanced Vehicular Systems, Mississippi State University, 200 Research Boulevard, Starkville, MS 39759, USA;
| | - John E. Ball
- Human Factors and Athlete Engineering, Center for Advanced Vehicular Systems, Mississippi State University, 200 Research Boulevard, Starkville, MS 39759, USA;
- Department of Electrical and Computer Engineering, Mississippi State University, 406 Hardy Road, Starkville, MS 39762, USA
| | - Charles Freeman
- School of Human Sciences, Mississippi State University, 255 Tracy Drive, Starkville, MS 39762, USA;
| | - David M. Macias
- Department of Kinesiology, Mississippi State University, P.O. Box 6186, Starkville, MS 39762, USA;
- Columbus Orthopaedic Clinic, 670 Leigh Drive, Columbus, MS 39705, USA
| | - Chartrisa LaShan Simpson
- Department of Agricultural and Biological Engineering, Mississippi State University, 130 Creelman Street, Starkville, MS 39762, USA; (A.K.P.); (C.L.S.)
| | - Brian K. Smith
- Department of Industrial and Systems Engineering, Mississippi State University, 479-2 Hardy Road, Starkville, MS 39762, USA;
| | - Reuben F. Burch V.
- Human Factors and Athlete Engineering, Center for Advanced Vehicular Systems, Mississippi State University, 200 Research Boulevard, Starkville, MS 39759, USA;
- Department of Industrial and Systems Engineering, Mississippi State University, 479-2 Hardy Road, Starkville, MS 39762, USA;
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Liu X, Chuchvara N, Liu Y, Rao B. Real-time deep learning assisted skin layer delineation in dermal optical coherence tomography. OSA CONTINUUM 2021; 4:2008-2023. [PMID: 35822177 PMCID: PMC9273005 DOI: 10.1364/osac.426962] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We present deep learning assisted optical coherence tomography (OCT) imaging for quantitative tissue characterization and differentiation in dermatology. We utilize a manually scanned single fiber OCT (sfOCT) instrument to acquire OCT images from the skin. The focus of this study is to train a U-Net for automatic skin layer delineation. We demonstrate that U-Net allows quantitative assessment of epidermal thickness automatically. U-Net segmentation achieves high accuracy for epidermal thickness estimation for normal skin and leads to a clear differentiation between normal skin and skin lesions. Our results suggest that a single fiber OCT instrument with AI assisted skin delineation capability has the potential to become a cost-effective tool in clinical dermatology, for diagnosis and tumor margin detection.
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Affiliation(s)
- Xuan Liu
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
| | - Nadiya Chuchvara
- Center for Dermatology, Rutgers Robert Wood Johnson Medical School, 1 Worlds Fair Drive, Somerset, NJ 08873, USA
| | - Yuwei Liu
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
| | - Babar Rao
- Center for Dermatology, Rutgers Robert Wood Johnson Medical School, 1 Worlds Fair Drive, Somerset, NJ 08873, USA
- Rao Dermatology, 95 First Avenue, Atlantic Highlands, NJ 07716, USA
- Department of Dermatology, Weill Cornell Medicine, 1305 York Ave 9th Floor, New York, NY 10021, USA
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Ma Z, Bao G, Li J. Multifaceted Design and Emerging Applications of Tissue Adhesives. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007663. [PMID: 33956371 DOI: 10.1002/adma.202007663] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/04/2020] [Indexed: 05/24/2023]
Abstract
Tissue adhesives can form appreciable adhesion with tissues and have found clinical use in a variety of medical settings such as wound closure, surgical sealants, regenerative medicine, and device attachment. The advantages of tissue adhesives include ease of implementation, rapid application, mitigation of tissue damage, and compatibility with minimally invasive procedures. The field of tissue adhesives is rapidly evolving, leading to tissue adhesives with superior mechanical properties and advanced functionality. Such adhesives enable new applications ranging from mobile health to cancer treatment. To provide guidelines for the rational design of tissue adhesives, here, existing strategies for tissue adhesives are synthesized into a multifaceted design, which comprises three design elements: the tissue, the adhesive surface, and the adhesive matrix. The mechanical, chemical, and biological considerations associated with each design element are reviewed. Throughout the report, the limitations of existing tissue adhesives and immediate opportunities for improvement are discussed. The recent progress of tissue adhesives in topical and implantable applications is highlighted, and then future directions toward next-generation tissue adhesives are outlined. The development of tissue adhesives will fuse disciplines and make broad impacts in engineering and medicine.
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Affiliation(s)
- Zhenwei Ma
- Department of Mechanical Engineering, McGill University, Montréal, QC, H3A 0C3, Canada
| | - Guangyu Bao
- Department of Mechanical Engineering, McGill University, Montréal, QC, H3A 0C3, Canada
| | - Jianyu Li
- Department of Mechanical Engineering, McGill University, Montréal, QC, H3A 0C3, Canada
- Department of Biomedical Engineering, McGill University, Montréal, QC, H3A 2B4, Canada
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Witte M, Rübhausen M, Jaspers S, Wenck H, Fischer F. A method to analyze the influence of mechanical strain on dermal collagen morphologies. Sci Rep 2021; 11:7565. [PMID: 33828115 PMCID: PMC8027212 DOI: 10.1038/s41598-021-86907-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 02/17/2021] [Indexed: 11/09/2022] Open
Abstract
Collagen fibers and their orientation play a major role in the mechanical behavior of soft biological tissue such as skin. Here, we present a proof-of-principle study correlating mechanical properties with collagen fiber network morphologies. A dedicated multiphoton stretching device allows for mechanical deformations in combination with a simultaneous analysis of its collagen fiber network by second harmonic generation imaging (SHG). The recently introduced Fiber Image Network Evaluation (FINE) algorithm is used to obtain detailed information about the morphology with regard to fiber families in collagen network images. To demonstrate the potential of our method, we investigate an isotropic and an anisotropic ex-vivo dorsal pig skin sample under quasi-static cyclic stretching and relaxation sequences. Families of collagen fibers are found to form a partially aligned collagen network under strain. We find that the relative force uptake is accomplished in two steps. Firstly, fibers align within their fiber families and, secondly, fiber families orient in the direction of force. The maximum alignment of the collagen fiber network is found to be determined by the largest strain. Isotropic and anisotropic samples reveal a different micro structural behavior under repeated deformation leading to a similar force uptake after two stretching cycles. Our method correlates mechanical properties with morphologies in collagen fiber networks.
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Affiliation(s)
- Maximilian Witte
- Center for Free-Electron Laser Science (CFEL), University of Hamburg, Hamburg, 22607, Germany.,Beiersdorf AG, Hamburg, 20245, Germany
| | - Michael Rübhausen
- Center for Free-Electron Laser Science (CFEL), University of Hamburg, Hamburg, 22607, Germany
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Sato ET, Machado N, Araújo DR, Paulino LC, Martinho H. Fourier transform infrared absorption (FTIR) on dry stratum corneum, corneocyte-lipid interfaces: experimental and vibrational spectroscopy calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 249:119218. [PMID: 33341746 DOI: 10.1016/j.saa.2020.119218] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/13/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
Many questions concerning the biophysical and physiological properties of skin are still open. Skin aging, permeability, dermal absorption, hydration, and drug transdermal delivery, are few examples of processes with unveiled underlying mechanisms. In this work, it is presented a comparison between Fourier transform infrared absorption (FTIR) of dry stratum corneum and stratum corneum under lipase action supported by first-principles density functional vibrational calculations. The molecular structure of stratum corneum was modeled by an archetype of its hygroscopic proteic portion inside the corneocytes, the natural moisturizing factor, coupled to glycerol molecules which represent the lipid fraction of stratum corneum. Vibrational spectra were calculated and compared to experimental data obtained on the animal model of stratum corneum. The experimental results indicated prominent spectral differences between dry and lipase-treated stratum corneum. Principal components analysis and hyerarchical clustering indicated that 1200, 1650, and 1695 cm-1 bands are the most influential on the discrimination. It is noticed that bands in the fingerprint region (800-1800 cm-1) were correctly assigned. Moreover, the calculations revealed the existence of two coupled vibration between the hydroxyl group of lipid and methylene (1120 and 1160 cm-1), which are of special interest since they probe the lipid-amino acid coupling. The model was also able to predict the shear modulus of dry stratum corneum in excellent agreement with the reported values from the literature. Other physical/chemical properties could be calculated exploring the chemical accuracy and molecular resolution of this model. Research in dermatology, cosmetology, and biomedical engineering in the specific topics of drug delivery and/or mechanical properties of skin are examples of fields that would potentially take advantage of this approach.
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Affiliation(s)
- Erika T Sato
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP 09210-580, Brazil
| | - Neila Machado
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP 09210-580, Brazil
| | - Daniele R Araújo
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP 09210-580, Brazil
| | - Luciana C Paulino
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP 09210-580, Brazil
| | - Herculano Martinho
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP 09210-580, Brazil.
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Sachs D, Wahlsten A, Kozerke S, Restivo G, Mazza E. A biphasic multilayer computational model of human skin. Biomech Model Mechanobiol 2021; 20:969-982. [PMID: 33566274 PMCID: PMC8154831 DOI: 10.1007/s10237-021-01424-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 01/12/2021] [Indexed: 11/26/2022]
Abstract
The present study investigates the layer-specific mechanical behavior of human skin. Motivated by skin’s histology, a biphasic model is proposed which differentiates between epidermis, papillary and reticular dermis, and hypodermis. Inverse analysis of ex vivo tensile and in vivo suction experiments yields mechanical parameters for each layer and predicts a stiff reticular dermis and successively softer papillary dermis, epidermis and hypodermis. Layer-specific analysis of simulations underlines the dominating role of the reticular dermis in tensile loading. Furthermore, it shows that the observed out-of-plane deflection in ex vivo tensile tests is a direct consequence of the layered structure of skin. In in vivo suction experiments, the softer upper layers strongly influence the mechanical response, whose dissipative part is determined by interstitial fluid redistribution within the tissue. Magnetic resonance imaging-based visualization of skin deformation in suction experiments confirms the deformation pattern predicted by the multilayer model, showing a consistent decrease in dermal thickness for large probe opening diameters.
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Affiliation(s)
- David Sachs
- ETH Zurich, Institute for Mechanical Systems, Zürich, Switzerland
| | - Adam Wahlsten
- ETH Zurich, Institute for Mechanical Systems, Zürich, Switzerland
| | - Sebastian Kozerke
- University and ETH Zurich, Institute for Biomedical Engineering, Zürich, Switzerland
| | - Gaetana Restivo
- Department of Dermatology, University Hospital Zürich, Zürich, Switzerland
| | - Edoardo Mazza
- ETH Zurich, Institute for Mechanical Systems, Zürich, Switzerland
- EMPA, Swiss Federal Laboratories for Materials Science and Technology, Experimental Continuum Mechanics, Dübendorf, Switzerland
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Mondésert H, Bossard F, Favier D. Anisotropic electrospun honeycomb polycaprolactone scaffolds: Elaboration, morphological and mechanical properties. J Mech Behav Biomed Mater 2020; 113:104124. [PMID: 33091720 DOI: 10.1016/j.jmbbm.2020.104124] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/01/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022]
Abstract
Tissue engineering technology requires porous scaffolds, based on biomaterials, which have to mimic as closely as possible the morphological and anisotropic mechanical properties of the native tissue to substitute. Anisotropic fibrous scaffolds fabricated by template-assisted electrospinning are investigated in this study. Fibers of electrospun Polycaprolactone (PCL) were successfully arranged spatially into honeycomb structures by using well-shaped 3D micro-architected metal collectors. Fibrous scaffolds present 2 × 4 mm2 wide elementary patterns with low and high fiber density areas. Distinct regions of the honeycomb patterns were analyzed through SEM images revealing different fiber diameters with specific fiber orientation depending on the regions of interest. Tensile test experiments were carried out with an optical observation of the local deformation at the pattern scale, allowing the determination and analysis, at small and large deformation, of the axial and transverse local strains. The honeycomb patterned mats showed significantly different mechanical properties along the two orthogonal directions probing an anisotropic ratio of 4.2. Stress relaxation test was performed on scaffolds at 15% of strain. This measurement pointed out the low contribution of the viscosity of about 20% in the mechanical response of the scaffold. An orthotropic linear elastic model was consequently proposed to characterize the anisotropic behavior of the produced patterned membranes. This new versatile method to produce architected porous materials, adjustable to several polymers and structures, will provide appealing benefits for soft regenerative medicine application and the development of custom-made scaffolds.
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Affiliation(s)
- Hugues Mondésert
- Univ. Grenoble Alpes, CNRS, Grenoble INP(1), LRP, Grenoble, 38000, France; Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP(1), TIMC-IMAG, Grenoble, 38000, France
| | - Frédéric Bossard
- Univ. Grenoble Alpes, CNRS, Grenoble INP(1), LRP, Grenoble, 38000, France.
| | - Denis Favier
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP(1), TIMC-IMAG, Grenoble, 38000, France
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