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Huang J, Jia M, Li Y, Yan M, Wang K, Li X. Finite element simulation and experimental validation of thermal damage to isolated porcine skin tissue by femtosecond laser welding. JOURNAL OF BIOPHOTONICS 2024:e202400224. [PMID: 39049557 DOI: 10.1002/jbio.202400224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/12/2024] [Accepted: 07/05/2024] [Indexed: 07/27/2024]
Abstract
The welding effect of the laser on skin tissue is reduced by thermal damage to skin tissue, and greater thermal damage to skin tissue caused by the laser is prevented by predicting thermal damage. In this paper, a finite element model is established for the temperature field of skin tissue scanned by a femtosecond laser to obtain the influence of laser process parameters and scanning path on the thermal damage parameters of skin tissue and the thermal damage area, and verified experimentally. The results show that the established finite element model is accurate and can accurately reflect the temperature distribution during the process of femtosecond laser welding of porcine skin tissues; used to predict the thermal damage parameters of the skin tissues and the thermal damage area; and provide guidance for the study of the femtosecond laser welding of the skin tissues process to obtain the optimal process parameters.
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Affiliation(s)
- Jun Huang
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Mengshi Jia
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Yanyu Li
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Mintao Yan
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Kehong Wang
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Xiaopeng Li
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
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2
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Huang J, Jia M, Xia S, Chen Y, Xu T, Wu J, Li X, Wang K, Rui Y. Effect of femtosecond laser process parameters on the thermal denaturation degree of skin tissue. JOURNAL OF BIOPHOTONICS 2024; 17:e202300497. [PMID: 38282467 DOI: 10.1002/jbio.202300497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/30/2024]
Abstract
The influence of femtosecond laser parameters on the degree of thermal denaturation was studied experimentally. The relationship between the degree of thermal denaturation and the characteristic parameters of skin microstructure and the secondary structure of skin tissue proteins in characterizing the degree of thermal damage was analyzed. The results showed the interaction of laser power, laser power, and scanning speed had a significant effect on the degree of thermal denaturation; greater degrees of thermal denaturation were associated with larger second-order moments of the texture angle of the skin microtissue and smaller entropy values and contrast, indicating a greater degree of thermal damage; and higher peak temperature, the lower peak intensity of Raman spectra, decrease in the percentage area of α-helix fitted curves and increase in the percentage area of β-sheet and β-turn fitted curves indicate that the protein is denatured to a large extent that means thermal damage is large.
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Affiliation(s)
- Jun Huang
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Mengshi Jia
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Shengnan Xia
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Yuxin Chen
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Tongyu Xu
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Jinjin Wu
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Xiaopeng Li
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Kehong Wang
- School of Material Science and Technology, Nanjing University of Science and Technology, Nanjing, China
| | - Yunfeng Rui
- Zhongda Hospital·Department of Orthopedics, Southeast University, Nanjing, China
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3
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Nomura K, Fiala T, Wennemers H. Carbohydrate Co-Solutes Stabilize Collagen Triple Helices. Chembiochem 2024; 25:e202300860. [PMID: 38233350 DOI: 10.1002/cbic.202300860] [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: 12/21/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
Carbohydrates are common co-solutes for the stabilization of proteins. The effect of carbohydrate solutions on the stability of collagen, the most abundant protein in mammals, is, however, underexplored. In this work, we studied the thermal stability of collagen triple helices derived from a molecularly defined collagen model peptide (CMP), Ac-(Pro-Hyp-Gly)7 -NH2 , in solutions of six common mono- and disaccharides. We show that the carbohydrates stabilize the collagen triple helix in a concentration-dependent manner, with an increase of the melting temperature of up to 17 °C. In addition, we show that the stabilizing effect is similar for all studied sugars, including trehalose, which is otherwise considered a privileged bioprotectant. The results provided insight into the effects of sugar co-solutes on collagen triple helices and can aid the selection of storage environments for collagen-based materials and probes.
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Affiliation(s)
- Kota Nomura
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Tomas Fiala
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Helma Wennemers
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
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4
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Griebel M, Vasan A, Chen C, Eyckmans J. Fibroblast clearance of damaged tissue following laser ablation in engineered microtissues. APL Bioeng 2023; 7:016112. [PMID: 36938481 PMCID: PMC10017124 DOI: 10.1063/5.0133478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/06/2023] [Indexed: 03/15/2023] Open
Abstract
Although the mechanisms underlying wound healing are largely preserved across wound types, the method of injury can affect the healing process. For example, burn wounds are more likely to undergo hypertrophic scarring than are lacerations, perhaps due to the increased underlying damage that needs to be cleared. This tissue clearance is thought to be mainly managed by immune cells, but it is unclear if fibroblasts contribute to this process. Herein, we utilize a 3D in vitro model of stromal wound healing to investigate the differences between two modes of injury: laceration and laser ablation. We demonstrate that laser ablation creates a ring of damaged tissue around the wound that is cleared by fibroblasts prior to wound closure. This process is dependent on ROCK and dynamin activity, suggesting a phagocytic or endocytic process. Transmission electron microscopy of fibroblasts that have entered the wound area reveals large intracellular vacuoles containing fibrillar extracellular matrix. These results demonstrate a new model to study matrix clearance by fibroblasts in a 3D soft tissue. Because aberrant wound healing is thought to be caused by an imbalance between matrix degradation and production, this model, which captures both aspects, will be a valuable addition to the study of wound healing.
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Affiliation(s)
- Megan Griebel
- Department of Biomedical Engineering and the Biological Design Center, Boston University, Boston, Massachusetts 02215, USA
| | - Anish Vasan
- Department of Biomedical Engineering and the Biological Design Center, Boston University, Boston, Massachusetts 02215, USA
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5
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Fiala T, Barros EP, Heeb R, Riniker S, Wennemers H. Predicting Collagen Triple Helix Stability through Additive Effects of Terminal Residues and Caps. Angew Chem Int Ed Engl 2023; 62:e202214728. [PMID: 36409045 PMCID: PMC10108146 DOI: 10.1002/anie.202214728] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/23/2022]
Abstract
Collagen model peptides (CMPs) consisting of proline-(2S,4R)-hydroxyproline-glycine (POG) repeats have provided a breadth of knowledge of the triple helical structure of collagen, the most abundant protein in mammals. Predictive tools for triple helix stability have, however, lagged behind since the effect of CMPs with different frames ([POG]n , [OGP]n , or [GPO]n ) and capped or uncapped termini have so far been underestimated. Here, we elucidated the impact of the frame, terminal functional group and its charge on the stability of collagen triple helices. Combined experimental and theoretical studies with frame-shifted, capped and uncapped CMPs revealed that electrostatic interactions, strand preorganization, interstrand H-bonding, and steric repulsion at the termini contribute to triple helix stability. We show that these individual contributions are additive and allow for the prediction of the melting temperatures of CMP trimers.
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Affiliation(s)
- Tomas Fiala
- Laboratory of Organic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Emilia P Barros
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Rahel Heeb
- Laboratory of Organic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Helma Wennemers
- Laboratory of Organic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
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6
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Nelson MS, Liu Y, Wilson HM, Li B, Rosado-Mendez IM, Rogers JD, Block WF, Eliceiri KW. Multiscale Label-Free Imaging of Fibrillar Collagen in the Tumor Microenvironment. Methods Mol Biol 2023; 2614:187-235. [PMID: 36587127 DOI: 10.1007/978-1-0716-2914-7_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
With recent advances in cancer therapeutics, there is a great need for improved imaging methods for characterizing cancer onset and progression in a quantitative and actionable way. Collagen, the most abundant extracellular matrix protein in the tumor microenvironment (and the body in general), plays a multifaceted role, both hindering and promoting cancer invasion and progression. Collagen deposition can defend the tumor with immunosuppressive effects, while aligned collagen fiber structures can enable tumor cell migration, aiding invasion and metastasis. Given the complex role of collagen fiber organization and topology, imaging has been a tool of choice to characterize these changes on multiple spatial scales, from the organ and tumor scale to cellular and subcellular level. Macroscale density already aids in the detection and diagnosis of solid cancers, but progress is being made to integrate finer microscale features into the process. Here we review imaging modalities ranging from optical methods of second harmonic generation (SHG), polarized light microscopy (PLM), and optical coherence tomography (OCT) to the medical imaging approaches of ultrasound and magnetic resonance imaging (MRI). These methods have enabled scientists and clinicians to better understand the impact collagen structure has on the tumor environment, at both the bulk scale (density) and microscale (fibrillar structure) levels. We focus on imaging methods with the potential to both examine the collagen structure in as natural a state as possible and still be clinically amenable, with an emphasis on label-free strategies, exploiting intrinsic optical properties of collagen fibers.
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Affiliation(s)
- Michael S Nelson
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Yuming Liu
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI, USA
| | - Helen M Wilson
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Bin Li
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.,Morgridge Institute for Research, Madison, WI, USA
| | - Ivan M Rosado-Mendez
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Jeremy D Rogers
- Morgridge Institute for Research, Madison, WI, USA.,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Walter F Block
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Kevin W Eliceiri
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI, USA. .,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA. .,Morgridge Institute for Research, Madison, WI, USA. .,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA. .,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA.
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7
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Fiala T, Barros EP, Ebert MO, Ruijsenaars E, Riniker S, Wennemers H. Frame Shifts Affect the Stability of Collagen Triple Helices. J Am Chem Soc 2022; 144:18642-18649. [PMID: 36179150 DOI: 10.1021/jacs.2c08727] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Collagen model peptides (CMPs), composed of proline-(2S,4R)-hydroxyproline-glycine (POG) repeat units, have been extensively used to study the structure and stability of triple-helical collagen─the dominant structural protein in mammals─at the molecular level. Despite the more than 50-year history of CMPs and numerous studies on the relationship between the composition of single-stranded CMPs and the thermal stability of the assembled triple helices, little attention has been paid to the effects arising from their terminal residues. Here, we show that frame-shifted CMPs, which share POG repeat units but terminate with P, O, or G, form triple helices with vastly different thermal stabilities. A melting temperature difference as high as 16 °C was found for triple helices from 20-mers Ac-OG[POG]6-NH2 and Ac-[POG]6PO-NH2, and triple helices of the constitutional isomers Ac-[POG]7-NH2 and Ac-[GPO]7-NH2 melt 10 °C apart. A combination of thermal denaturation, circular dichroism and NMR spectroscopic studies, and molecular dynamics simulations revealed that the stability differences originate from the propensity of the peptide termini to preorganize into a polyproline-II helical structure. Our results advise that care must be taken when designing peptide mimics of structural proteins, as subtle changes in the terminal residues can significantly affect their properties. Our findings also provide a general and straightforward tool for tuning the stability of CMPs for applications as synthetic materials and biological probes.
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Affiliation(s)
- Tomas Fiala
- Laboratory of Organic Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 3, Zurich 8093, Switzerland
| | - Emilia P Barros
- Laboratory of Physical Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
| | - Marc-Olivier Ebert
- Laboratory of Organic Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 3, Zurich 8093, Switzerland
| | - Enrico Ruijsenaars
- Laboratory of Physical Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
| | - Helma Wennemers
- Laboratory of Organic Chemistry, ETH Zurich, D-CHAB, Vladimir-Prelog-Weg 3, Zurich 8093, Switzerland
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8
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Wang Y, Ma Y, Jiang Z, Hu H, Wang S, Chi J, Qiao J, Zhang W, Wang Z, Liu W, Han B. Multifunctional effects of wound dressing based on chitosan-coordinated argentum with resistant bacterial penetration. Carbohydr Polym 2022; 288:119329. [PMID: 35450618 DOI: 10.1016/j.carbpol.2022.119329] [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] [Received: 08/09/2021] [Revised: 02/21/2022] [Accepted: 03/06/2022] [Indexed: 11/30/2022]
Abstract
Third-degree scald, causing serious tissue destruction with continuous pain, easily leads to microbial infections and delayed wound healing. Therefore, a multifunctional treatment is attractive for seriously damaged tissue. Herein, carboxymethyl chitosan-coordinated argentum (Ag-CMC) was synthesized via a complexation method, and then the Ag+ release, antibacterial activity, biocompatibility, pain relief and wound healing properties of Ag-CMC were investigated in vitro and in vivo. The results revealed that Ag+ had interacted with carboxymethyl chitosan, containing approximately 1.2% of silver. The Ag-CMC (50-200 μg/mL) with Ag+ sustained release exhibited significant antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, drug-resistant E. coli, PA, MRSA and good biocompatibility with L929 cells. Furthermore, antibacterial and wound healing experiments demonstrated that Ag-CMC achieved an effective contraction rate of 90% after 28 days by accelerating re-epithelialization, regulating inflammation response, relieving pain and infections. Therefore, Ag-CMC is a safe multifunctional treatment for wound healing and infections.
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Affiliation(s)
- Yanting Wang
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Yanhui Ma
- Department of Laboratory Medicine, Qingdao Central Hospital, Second Affiliated Hospital of Qingdao University, Qingdao 266042, PR China
| | - Zhiwen Jiang
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Pilot National Laboratory for Marine Science and Technology, Qingdao 266235, PR China
| | - Huiwen Hu
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Shuo Wang
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Jinhua Chi
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Jing Qiao
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Wei Zhang
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Zheng Wang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao 266071, PR China; Department of Reproductive Medicine, the Affiliated Hospital of Qingdao University, Qingdao 266003, PR China
| | - Wanshun Liu
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Baoqin Han
- Laboratory of Biochemistry and Biomedical Materials, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Pilot National Laboratory for Marine Science and Technology, Qingdao 266235, PR China.
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9
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Chattopadhyay S, Teixeira LBC, Kiessling LL, McAnulty JF, Raines RT. Bifunctional Peptide that Anneals to Damaged Collagen and Clusters TGF-β Receptors Enhances Wound Healing. ACS Chem Biol 2022; 17:314-321. [PMID: 35084170 DOI: 10.1021/acschembio.1c00745] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transforming growth factor-β (TGF-β) plays important roles in wound healing. The activity of TGF-β is initiated upon the binding of the growth factor to the extracellular domains of its receptors. We sought to facilitate the activation by clustering these extracellular domains. To do so, we used a known peptide that binds to TGF-β receptors without diminishing their affinity for TGF-β. We conjugated this peptide to a collagen-mimetic peptide that can anneal to the damaged collagen in a wound bed. We find that the conjugate enhances collagen deposition and wound closure in mice in a manner consistent with the clustering of TGF-β receptors. This strategy provides a means to upregulate the TGF-β signaling pathway without adding exogenous TGF-β and could inspire means to treat severe wounds.
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Affiliation(s)
- Sayani Chattopadhyay
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Leandro B. C. Teixeira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Laura L. Kiessling
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Department of Biochemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jonathan F. McAnulty
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Ronald T. Raines
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Department of Biochemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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10
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Liu Z, Chiang CY, Nip J, Feng L, Zhang Y, Rocha S, Georgakoudi I. Nicotinamide effects on the metabolism of human fibroblasts and keratinocytes assessed by quantitative, label-free fluorescence imaging. BIOMEDICAL OPTICS EXPRESS 2021; 12:6375-6390. [PMID: 34745743 PMCID: PMC8548000 DOI: 10.1364/boe.432561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/28/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Alterations in metabolism are central to the aging process. Therefore, understanding the subcellular functional and structural changes associated with metabolic aging is critical. Current established methods for exploring cell metabolism either require the use of exogenous agents or are destructive to the tissue or cells. Two-photon excited fluorescence (TPEF) imaging has emerged as a method for monitoring subtle metabolic changes non-invasively. In this study, we use TPEF imaging to acquire high-resolution fluorescence images from two coenzymes, NAD(P)H (reduced form of nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), within human fibroblasts and keratinocytes in response to B3 (a nicotinamide precursor) supplementation and/or UV irradiation, without addition of exogenous labels. In addition, multi-parametric analysis methods are used to extract functional information of cellular metabolism, including cellular redox state, NAD(P)H fluorescence lifetime, and mitochondrial organization. Our results demonstrate that such optical metabolic assessments can serve as sensitive, label-free, non-destructive reporters of known effects of B3 to maintain and in some cases even enhance the respiratory function of mitochondria, while lowering oxidative damage. Thus, TPEF imaging, supported by highly-quantitative analysis, can serve as a tool to understand aging-dependent metabolic changes as well as the effect of actives on human epidermal and dermal cells.
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Affiliation(s)
- Zhiyi Liu
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
- Currently with the State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering; International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | | | - John Nip
- Unilever Research and Development, Trumbull, CT 06611, USA
| | - Lin Feng
- Unilever Research and Development, Trumbull, CT 06611, USA
| | - Yang Zhang
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Sheila Rocha
- Unilever Research and Development, Trumbull, CT 06611, USA
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
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11
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Phelan HA, Holmes Iv JH, Hickerson WL, Cockerell CJ, Shupp JW, Carter JE. Use of 816 consecutive burn wound biopsies to inform a histologic algorithm for burn depth categorization. J Burn Care Res 2021; 42:1162-1167. [PMID: 34387313 DOI: 10.1093/jbcr/irab158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Burn experts are only 77% accurate when subjectively assessing burn depth, leaving almost a quarter of patients to undergo unnecessary surgery or conversely suffer a delay in treatment. To aid clinicians in burn depth assessment (BDA), new technologies are being studied with machine learning algorithms calibrated to histologic standards. Our group has iteratively created a theoretical burn biopsy algorithm (BBA) based on histologic analysis, and subsequently informed it with the largest burn wound biopsy repository in the literature. Here, we sought to report that process. METHODS The was an IRB-approved, prospective, multicenter study. A BBA was created a priori and refined in an iterative manner. Patients with burn wounds assessed by burn experts as requiring excision and autograft underwent 4mm biopsies procured every 25cm 2. Serial still photos were obtained at enrollment and at excision intraoperatively. Burn biopsies were histologically assessed for presence/absence of epidermis, papillary dermis, reticular dermis, and proportion of necrotic adnexal structures by a dermatopathologist using H&E with whole slide scanning. First degree and superficial 2 nd degree were considered to be burn wounds likely to have healed without surgery, while deep 2 nd and 3 rd degree burns were considered unlikely to heal by 21 days. Biopsy pathology results were correlated with still photos by five burn experts for consensus of final burn depth diagnosis. RESULTS Sixty-six subjects were enrolled with 117 wounds and 816 biopsies. The BBA was used to categorize subjects' wounds into 4 categories: 7% of burns were categorized as 1 st degree, 13% as superficial 2 nd degree, 43% as deep 2 nd degree, and 37% as 3 rd degree. Therefore 20% of burn wounds were incorrectly judged as needing excision and grafting by the clinical team as per the BBA. As H&E is unable to assess the viability of papillary and reticular dermis, with time our team came to appreciate the greater importance of adnexal structure necrosis over dermal appearance in assessing healing potential. CONCLUSIONS Our study demonstrates that a BBA with objective histologic criteria can be used to categorize BDA with clinical misclassification rates consistent with past literature. This study serves as the largest analysis of burn biopsies by modern day burn experts and the first to define histologic parameters for BDA.
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Affiliation(s)
- Herb A Phelan
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
| | - James H Holmes Iv
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
| | - William L Hickerson
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
| | - Clay J Cockerell
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
| | - Jeffrey W Shupp
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
| | - Jeffrey E Carter
- LSUHSC-New Orleans, Department of Surgery, University Medical Center-New Orleans Burn Program, 2000 Canal Street, Tower 1, Floor 3, New Orleans, LA
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12
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Li H, Cheng F, Orgill DP, Yao J, Zhang YS. Handheld bioprinting strategies for in situ wound dressing. Essays Biochem 2021; 65:533-543. [PMID: 34028545 PMCID: PMC8720383 DOI: 10.1042/ebc20200098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 01/06/2023]
Abstract
Handheld bioprinting has recently attracted considerable attention as a technology to deliver biomaterials and/or cells to injury sites by using freeform, user-instructed deposition approaches, specifically targeted towards in situ wound dressing and healing. In this review, we present a concise introduction of handheld bioprinting, and a thorough discussion on design and manufacture of handheld bioprinters and choice over bioinks. Finally, the advantages, challenges, and prospective of the said technologies are elaborated. It is believed that handheld bioprinting will play an essential role in the field of in situ wound healing mainly due to its excellent portability, user-friendliness, cost-effectiveness, and amenability to various wound needs.
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Affiliation(s)
- Hongbin Li
- Division of Engineering in Medicine, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Cambridge, MA 02139, U.S.A
- College of Light Industry and Textile, Qiqihar University, Qiqihar, Heilongjiang 161000, P.R. China
| | - Feng Cheng
- Division of Engineering in Medicine, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Cambridge, MA 02139, U.S.A
| | - Dennis P. Orgill
- Department of Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, U.S.A
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, U.S.A
| | - Yu Shrike Zhang
- Division of Engineering in Medicine, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Cambridge, MA 02139, U.S.A
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Xu Y, Kirchner M. Collagen Mimetic Peptides. Bioengineering (Basel) 2021; 8:5. [PMID: 33466358 PMCID: PMC7824840 DOI: 10.3390/bioengineering8010005] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/24/2020] [Accepted: 12/31/2020] [Indexed: 12/20/2022] Open
Abstract
Since their first synthesis in the late 1960s, collagen mimetic peptides (CMPs) have been used as a molecular tool to study collagen, and as an approach to develop novel collagen mimetic biomaterials. Collagen, a major extracellular matrix (ECM) protein, plays vital roles in many physiological and pathogenic processes. Applications of CMPs have advanced our understanding of the structure and molecular properties of a collagen triple helix-the building block of collagen-and the interactions of collagen with important molecular ligands. The accumulating knowledge is also paving the way for developing novel CMPs for biomedical applications. Indeed, for the past 50 years, CMP research has been a fast-growing, far-reaching interdisciplinary field. The major development and achievement of CMPs were documented in a few detailed reviews around 2010. Here, we provided a brief overview of what we have learned about CMPs-their potential and their limitations. We focused on more recent developments in producing heterotrimeric CMPs, and CMPs that can form collagen-like higher order molecular assemblies. We also expanded the traditional view of CMPs to include larger designed peptides produced using recombinant systems. Studies using recombinant peptides have provided new insights on collagens and promoted progress in the development of collagen mimetic fibrillar self-assemblies.
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Affiliation(s)
- Yujia Xu
- Department of Chemistry, Hunter College of the City University of New York, 695 Park Ave., New York, NY 10065, USA;
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