1
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Dvorak N, Liu Z, Mouthuy PA. Soft bioreactor systems: a necessary step toward engineered MSK soft tissue? Front Robot AI 2024; 11:1287446. [PMID: 38711813 PMCID: PMC11070535 DOI: 10.3389/frobt.2024.1287446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/12/2024] [Indexed: 05/08/2024] Open
Abstract
A key objective of tissue engineering (TE) is to produce in vitro funcional grafts that can replace damaged tissues or organs in patients. TE uses bioreactors, which are controlled environments, allowing the application of physical and biochemical cues to relevant cells growing in biomaterials. For soft musculoskeletal (MSK) tissues such as tendons, ligaments and cartilage, it is now well established that applied mechanical stresses can be incorporated into those bioreactor systems to support tissue growth and maturation via activation of mechanotransduction pathways. However, mechanical stresses applied in the laboratory are often oversimplified compared to those found physiologically and may be a factor in the slow progression of engineered MSK grafts towards the clinic. In recent years, an increasing number of studies have focused on the application of complex loading conditions, applying stresses of different types and direction on tissue constructs, in order to better mimic the cellular environment experienced in vivo. Such studies have highlighted the need to improve upon traditional rigid bioreactors, which are often limited to uniaxial loading, to apply physiologically relevant multiaxial stresses and elucidate their influence on tissue maturation. To address this need, soft bioreactors have emerged. They employ one or more soft components, such as flexible soft chambers that can twist and bend with actuation, soft compliant actuators that can bend with the construct, and soft sensors which record measurements in situ. This review examines types of traditional rigid bioreactors and their shortcomings, and highlights recent advances of soft bioreactors in MSK TE. Challenges and future applications of such systems are discussed, drawing attention to the exciting prospect of these platforms and their ability to aid development of functional soft tissue engineered grafts.
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Affiliation(s)
| | | | - Pierre-Alexis Mouthuy
- Botnar Institute of Musculoskeletal Sciences, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
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2
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Sasso G, Pugno N, Busfield JJC, Carpi F. Soft robotic patterning of liquids. Sci Rep 2023; 13:15739. [PMID: 37735476 PMCID: PMC10514051 DOI: 10.1038/s41598-023-41755-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 08/31/2023] [Indexed: 09/23/2023] Open
Abstract
Patterning of two or more liquids, either homogeneous in each phase or mixed with particles (including biological matter, such as cells and proteins), by controlling their flow dynamics, is relevant to several applications. Examples include dynamic spatial confinement of liquids in microfluidic systems (such as lab-on-a-chip and organ-on-a-chip devices) or structuring of polymers to modulate various properties (such as strength, conductivity, transparency and surface finishing). State-of-the-art strategies use various technologies, including positioners, shakers and acoustic actuators, which often combine limited versatility of mixing with significant inefficiency, energy consumption, and noise, as well as tendency to increase the temperature of the liquids. Here, we describe a new kind of robotic mixers of liquids, based on electro-responsive smart materials (dielectric elastomer actuators). We show for the first time how an efficient soft robotic device can be used to produce, via combinations of rotations and translations, various spatial patterns in liquids and maintain them stable for a few minutes. Moreover, we show that, as compared to a conventional orbital shaker, the new type of robotic device can mix liquids with a higher efficacy (~ 94% relative to ~ 80%, after 8 min of mixing) and with a significantly lower increase of the liquids' temperature (+ 1 °C relative to + 5 °C, after 6 h of mixing). This is especially beneficial when mixing should occur according to controllable spatial features and should involve temperature-sensitive matter (such as biological cells, proteins, pre-polymers and other thermolabile molecules).
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Affiliation(s)
- Giacomo Sasso
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Rd, London, E1 4NS, UK
| | - Nicola Pugno
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Rd, London, E1 4NS, UK
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy
| | - James J C Busfield
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Rd, London, E1 4NS, UK.
| | - Federico Carpi
- Department of Industrial Engineering, University of Florence, Via di Santa Marta 3, 50139, Florence, Italy.
- IRCCS Fondazione don Carlo Gnocchi ONLUS, Via di Scandicci 269, 50143, Florence, Italy.
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3
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Wu YH, Park TIH, Kwon E, Feng S, Schweder P, Dragunow M, Shim V, Rosset S. Analyzing pericytes under mild traumatic brain injury using 3D cultures and dielectric elastomer actuators. Front Neurosci 2022; 16:994251. [DOI: 10.3389/fnins.2022.994251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022] Open
Abstract
Traumatic brain injury (TBI) is defined as brain damage due to an external force that negatively impacts brain function. Up to 90% of all TBI are considered in the mild severity range (mTBI) but there is still no therapeutic solution available. Therefore, further understanding of the mTBI pathology is required. To assist with this understanding, we developed a cell injury device (CID) based on a dielectric elastomer actuator (DEA), which is capable of modeling mTBI via injuring cultured cells with mechanical stretching. Our injury model is the first to use patient-derived brain pericyte cells, which are ubiquitous cells in the brain involved in injury response. Pericytes were cultured in our CIDs and mechanically strained up to 40%, and by at least 20%, prior to gene expression analysis. Our injury model is a platform capable of culturing and stretching primary human brain pericytes. The heterogeneous response in gene expression changes in our result may suggest that the genes implicated in pathological changes after mTBI could be a patient-dependent response, but requires further validation. The results of this study demonstrate that our CID is a suitable tool for simulating mTBI as an in vitro stretch injury model, that is sensitive enough to induce responses from primary human brain pericytes due to mechanical impacts.
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4
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Imboden M, Chen S, Gudozhnik O, Pollock C, Javor J, Bishop D, Shea H, Rosset S. The Integration of Optical Stimulation in a Mechanically Dynamic Cell Culture Substrate. Front Bioeng Biotechnol 2022; 10:934756. [PMID: 35928941 PMCID: PMC9344002 DOI: 10.3389/fbioe.2022.934756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 05/30/2022] [Indexed: 12/14/2022] Open
Abstract
A cell culture well with integrated mechanical and optical stimulation is presented. This is achieved by combining dielectric elastomer soft actuators, also known as artificial muscles, and a varifocal micro-electromechanical mirror that couples light from an optical fiber and focuses it onto the transparent cell substrate. The device enables unprecedented control of in vitro cell cultures by allowing the experimenter to tune and synchronize mechanical and optical stimuli, thereby enabling new experimental assays in optogenetics, fluorescent microscopy, or laser stimulation that include dynamic mechanical strain as a controlled input parameter.
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Affiliation(s)
- Matthias Imboden
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Sophia Chen
- Biomimetics Laboratory, Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Olexandr Gudozhnik
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Corey Pollock
- Department of Mechanical Engineering, Boston University, Boston, MA, United States
| | - Josh Javor
- Department of Mechanical Engineering, Boston University, Boston, MA, United States
| | - David Bishop
- Department of Mechanical Engineering, Boston University, Boston, MA, United States
| | - Herbert Shea
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Samuel Rosset
- Biomimetics Laboratory, Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- *Correspondence: Samuel Rosset,
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5
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He Q, Lin J, Zhou F, Cai D, Yan Y, Shan Y, Zhang S, Li T, Yao X, Ouyang H. “Musical dish” efficiently induces osteogenic differentiation of mesenchymal stem cells through music derived micro‐stretch with variable frequency. Bioeng Transl Med 2022; 7:e10291. [PMID: 35600662 PMCID: PMC9115692 DOI: 10.1002/btm2.10291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/01/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022] Open
Abstract
Nonuniform microstretching (NUMS) naturally occurs in real bone tissues in vivo, but its profound effects have not been identified yet. In order to explore the biological effects of NUMS and static stretch (uniform stretch [US]) on cells, a new “musical dish” device was developed. Musical signal was used to provide NUMS to cells. More stress fibers, arranging along the long axis of cells, were formed throughout the cells under NUMS, compared with US and untreated control group, although cell morphology did not show any alteration. Whole transcriptome sequencing revealed enhanced osteogenic differentiation of cells after NUMS treatment. Cells in the NUMS group showed a higher expression of bone‐related genes, while genes related to stemness and other lineages were down‐regulated. Our results give insights into the biological effects of NUMS and US on stem cell osteogenic differentiation, suggesting beneficial effects of micromechanical stimulus for osteogenesis. The newly developed device provides a basis for the development of NUMS derived rehabilitation technology to promote bone healing.
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Affiliation(s)
- Qiulin He
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
| | - Junxin Lin
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
| | - Fanghao Zhou
- Center for X‐Mechanics, Department of Engineering Mechanics Zhejiang University Hangzhou China
| | - Dandan Cai
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
| | - Yiyang Yan
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
| | - Yejie Shan
- Center for X‐Mechanics, Department of Engineering Mechanics Zhejiang University Hangzhou China
| | - Shufang Zhang
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
- China Orthopedic Regenerative Medicine Group (CORMed) Hangzhou China
| | - Tiefeng Li
- Center for X‐Mechanics, Department of Engineering Mechanics Zhejiang University Hangzhou China
| | - Xudong Yao
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine Yiwu China
| | - Hongwei Ouyang
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou China
- Department of Sports Medicine Zhejiang University School of Medicine Hangzhou China
- Zhejiang University‐University of Edinburgh Institute, Zhejiang University School of Medicine, and Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine Hangzhou China
- China Orthopedic Regenerative Medicine Group (CORMed) Hangzhou China
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6
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Mustapha KB, Hawwa MA, Abakr YA. Modeling and analysis of nature-inspired branched micropillars for enhanced dynamic bio-sensing. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3531. [PMID: 34536263 DOI: 10.1002/cnm.3531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/12/2021] [Indexed: 06/13/2023]
Abstract
Research evidence abounds on the effectiveness of micropillar-based microelectromechanical systems for the detection of a wide variety of ultrasmall biological objects for clinical and non-clinical applications. However, the standard micropillar-based sensing platforms rely on a single-column micropillar with a spot at the tip for binding of objects. Although this long-standing form has shown immense potential, performance improvement is hindered by the fundamental limits enforced by physical laws. Moreover, the single-column micropillar has a lower sensing area and is ill-suited for a simultaneous differential sensing of chemical/biological objects of different mass. Here, we report a new set of nature-inspired, branched micropillar-based sensing resonators to address the highlighted issues. The characteristics of the newly proposed branched micropillars are comprehensively examined with three payloads (Bartonella Bacilliformis, Escherichia coli, and Micro magnetic beads). Anchored on the capability of continuum theoretical framework, the mathematical model of the micropillar is formulated through the synthesis of the modified couple stress, the Rayleigh-Love, and the Timoshenko theories. The finite element method is employed to shed light on the variability of the structures' resonant response under performance reduction factors (payload's rotary inertia, damaged substrate, and density of a surrounding fluid). The results obtained indicate superior performance indicators for the triply-branched micropillar: enhanced response sensitivity for multiple payloads and less susceptibility to deterioration in resonant frequencies due to fluid immersion.
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Affiliation(s)
- Khameel B Mustapha
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (Malaysia Campus), Semenyih, Malaysia
| | - Muhammad A Hawwa
- Department of Mechanical Engineering and Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - Yousif A Abakr
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (Malaysia Campus), Semenyih, Malaysia
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7
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Correia Carreira S, Taghavi M, Pavez Loriè E, Rossiter J. FleXert: A Soft, Actuatable Multiwell Plate Insert for Cell Culture under Stretch. ACS Biomater Sci Eng 2021; 7:2225-2245. [PMID: 33843187 DOI: 10.1021/acsbiomaterials.0c01448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Porous multiwell plate inserts are widely used in biomedical research to study transport processes or to culture cells/tissues at the air-liquid interface. These inserts are made of rigid materials and used under static culture conditions, which are unrepresentative of biological microenvironments. Here, we present FleXert, a soft, actuatable cell culture insert that interfaces with six-well plates. It is made of polydimethylsiloxane (PDMS) and comprises a porous PDMS membrane as cell/tissue support. FleXerts can be pneumatically actuated using a standard syringe pump, imparting tensile strains of up to 30%. A wide range of actuation patterns can be achieved by varying the air pressure and pumping rate. Facile surface functionalization of FleXert's porous PDMS membrane with fibronectin enables adhesion of human dermal fibroblasts and strains developing on FleXert's membrane are successfully transduced to the cell layer. 3D tissue models, such as fibroblast-laden collagen gels, can also be anchored to PDMS following polydopamine coating. Furthermore, collagen-coated FleXert membranes support the establishment of a human skin model, demonstrating the material's excellent biocompatibility required for tissue engineering. In contrast to existing technologies, FleXerts do not require costly fabrication equipment or custom-built culture chambers, making them a versatile and low-cost solution for tissue engineering and biological barrier penetration studies under physiological strain. This paper is an extensive toolkit for multidisciplinary mechanobiology studies, including detailed instructions for a wide variety of methods such as device fabrication, theoretical modeling, cell culture, and image analysis techniques.
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Affiliation(s)
- Sara Correia Carreira
- School of Cellular and Molecular Medicine, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Majid Taghavi
- Bristol Robotics Laboratory, University of Bristol, T Block, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, United Kingdom
| | - Elizabeth Pavez Loriè
- Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, Düsseldorf 40225, Germany
| | - Jonathan Rossiter
- Bristol Robotics Laboratory, University of Bristol, T Block, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, United Kingdom
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8
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Fu S, Wei F, Yin C, Yao L, Wang Y. Biomimetic soft micro-swimmers: from actuation mechanisms to applications. Biomed Microdevices 2021; 23:6. [PMID: 33420838 DOI: 10.1007/s10544-021-00546-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2021] [Indexed: 12/26/2022]
Abstract
Underwater robot designs inspired by the behavior and morphological characteristics of aquatic animals can provide reinforced mobility and energy efficiency. In the past two decades, the emerging materials science and integrated circuit technology have been combined and applied to various types of bionic soft underwater miniaturized robots by researchers around the world. Further, the potential applications of biomimetic soft micro-swimmers in the biological and medical fields have been explored. Here, this paper reviews the development of biomimetic soft tiny swimmers, which are designed based on a variety of intelligent materials and control strategies. This review focuses on the various actuation mechanisms of soft tiny swimmers reported in the past two decades and classifies these robots into four categories: fish-like, snake-like, jellyfish-like and microbial-inspired ones. Besides, this review considers the practical challenges faced by actuation mechanisms of each type of robot, and summarizes and prospects how these challenges affect the potential applications of robots in real environments.
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Affiliation(s)
- Shihan Fu
- School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, China
| | - Fanan Wei
- School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, China.
| | - Chao Yin
- School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, China
| | - Ligang Yao
- School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, China
| | - Yaxiong Wang
- School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, China
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9
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Zhang W, Huang G, Xu F. Engineering Biomaterials and Approaches for Mechanical Stretching of Cells in Three Dimensions. Front Bioeng Biotechnol 2020; 8:589590. [PMID: 33154967 PMCID: PMC7591716 DOI: 10.3389/fbioe.2020.589590] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/09/2020] [Indexed: 12/21/2022] Open
Abstract
Mechanical stretch is widely experienced by cells of different tissues in the human body and plays critical roles in regulating their behaviors. Numerous studies have been devoted to investigating the responses of cells to mechanical stretch, providing us with fruitful findings. However, these findings have been mostly observed from two-dimensional studies and increasing evidence suggests that cells in three dimensions may behave more closely to their in vivo behaviors. While significant efforts and progresses have been made in the engineering of biomaterials and approaches for mechanical stretching of cells in three dimensions, much work remains to be done. Here, we briefly review the state-of-the-art researches in this area, with focus on discussing biomaterial considerations and stretching approaches. We envision that with the development of advanced biomaterials, actuators and microengineering technologies, more versatile and predictive three-dimensional cell stretching models would be available soon for extensive applications in such fields as mechanobiology, tissue engineering, and drug screening.
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Affiliation(s)
- Weiwei Zhang
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, China
| | - Guoyou Huang
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Chongqing University, Chongqing, China
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, China
| | - Feng Xu
- Bioinspired Engineering and Biomechanics Center, Xi’an Jiaotong University, Xi’an, China
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi’an Jiaotong University, Xi’an, China
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10
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Gao C, Li Z, Zou J, Cheng J, Jiang K, Liu C, Gu G, Tao W, Song J. Mechanical Effect on Gene Transfection Based on Dielectric Elastomer Actuator. ACS APPLIED BIO MATERIALS 2020; 3:2617-2625. [PMID: 35025395 DOI: 10.1021/acsabm.9b01199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Gene transfection has been widely applied in genome function and gene therapy. Although many efforts have been focused on designing carrier materials and transfection methods, the influence of mechanical stimulation on gene transfection efficiency has rarely been studied. Herein, dielectric elastomer actuator (DEA)-based stimulation bioreactors are designed to generate tensile and contractile stress on cells simultaneously. With the example of the EGFP transfection, cells with high membrane tension in the stretching stimulation regions had lower transfection efficiency, while the transfection efficiency of cells in the compressing regions tended to increase. Besides, the duty cycle and loading frequency of the applied stress on cells were also important factors that affect gene transfection efficiency. Furthermore, the pathways of cell endocytosis with the effect of mechanical stimulation were explored on the mechanism for the change of EGFP transfection efficiency. This design of the DEA-based bioreactor, as a strategy to study gene transfection efficiency, could be helpful for developing efficient transfection methods.
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Affiliation(s)
- Chao Gao
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Zhichao Li
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jiang Zou
- Robotics Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jin Cheng
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Kai Jiang
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Changrun Liu
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Guoying Gu
- Robotics Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Wei Tao
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jie Song
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.,Institute of Cancer and Basic Medicine (ICBM), Chinese Academy of Sciences; The Cancer Hospital of the University of Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, People's Republic of China
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11
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Costa J, Ghilardi M, Mamone V, Ferrari V, Busfield JJC, Ahluwalia A, Carpi F. Bioreactor With Electrically Deformable Curved Membranes for Mechanical Stimulation of Cell Cultures. Front Bioeng Biotechnol 2020; 8:22. [PMID: 32047746 PMCID: PMC6997204 DOI: 10.3389/fbioe.2020.00022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/10/2020] [Indexed: 11/13/2022] Open
Abstract
Physiologically relevant in vitro models of stretchable biological tissues, such as muscle, lung, cardiac and gastro-intestinal tissues, should mimic the mechanical cues which cells are exposed to in their dynamic microenvironment in vivo. In particular, in order to mimic the mechanical stimulation of tissues in a physiologically relevant manner, cell stretching is often desirable on surfaces with dynamically controllable curvature. Here, we present a device that can deform cell culture membranes without the current need for external pneumatic/fluidic or electrical motors, which typically make the systems bulky and difficult to operate. We describe a modular device that uses elastomeric membranes, which can intrinsically be deformed by electrical means, producing a dynamically tuneable curvature. This approach leads to compact, self-contained, lightweight and versatile bioreactors, not requiring any additional mechanical equipment. This was obtained via a special type of dielectric elastomer actuator. The structure, operation and performance of early prototypes are described, showing preliminary evidence on their ability to induce changes on the spatial arrangement of the cytoskeleton of fibroblasts dynamically stretched for 8 h.
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Affiliation(s)
- Joana Costa
- Research Center "E. Piaggio", University of Pisa, Pisa, Italy.,Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Michele Ghilardi
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom.,Materials Research Institute, Queen Mary University of London, London, United Kingdom
| | - Virginia Mamone
- Department of Information Engineering, University of Pisa, Pisa, Italy.,Department of Information Engineering, EndoCAS Center for Computer Assisted Surgery, University of Pisa, Pisa, Italy
| | - Vincenzo Ferrari
- Department of Information Engineering, University of Pisa, Pisa, Italy.,Department of Information Engineering, EndoCAS Center for Computer Assisted Surgery, University of Pisa, Pisa, Italy
| | - James J C Busfield
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom.,Materials Research Institute, Queen Mary University of London, London, United Kingdom
| | - Arti Ahluwalia
- Research Center "E. Piaggio", University of Pisa, Pisa, Italy.,Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Federico Carpi
- Department of Industrial Engineering, University of Florence, Florence, Italy
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12
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Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10020640] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.
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13
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Li Z, Gao C, Fan S, Zou J, Gu G, Dong M, Song J. Cell Nanomechanics Based on Dielectric Elastomer Actuator Device. NANO-MICRO LETTERS 2019; 11:98. [PMID: 34138039 PMCID: PMC7770812 DOI: 10.1007/s40820-019-0331-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/21/2019] [Indexed: 05/23/2023]
Abstract
As a frontier of biology, mechanobiology plays an important role in tissue and biomedical engineering. It is a common sense that mechanical cues under extracellular microenvironment affect a lot in regulating the behaviors of cells such as proliferation and gene expression, etc. In such an interdisciplinary field, engineering methods like the pneumatic and motor-driven devices have been employed for years. Nevertheless, such techniques usually rely on complex structures, which cost much but not so easy to control. Dielectric elastomer actuators (DEAs) are well known as a kind of soft actuation technology, and their research prospect in biomechanical field is gradually concerned due to their properties just like large deformation (> 100%) and fast response (< 1 ms). In addition, DEAs are usually optically transparent and can be fabricated into small volume, which make them easy to cooperate with regular microscope to realize real-time dynamic imaging of cells. This paper first reviews the basic components, principle, and evaluation of DEAs and then overview some corresponding applications of DEAs for cellular mechanobiology research. We also provide a comparison between DEA-based bioreactors and current custom-built devices and share some opinions about their potential applications in the future according to widely reported results via other methods.
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Affiliation(s)
- Zhichao Li
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Chao Gao
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Sisi Fan
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Jiang Zou
- Robotics Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Guoying Gu
- Robotics Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, 8000, Denmark
| | - Jie Song
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
- Shanghai Engineering Research Center of Advanced Dental Technology and Materials, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
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Sorba F, Poulin A, Ischer R, Shea H, Martin-Olmos C. Integrated elastomer-based device for measuring the mechanics of adherent cell monolayers. LAB ON A CHIP 2019; 19:2138-2146. [PMID: 31115420 DOI: 10.1039/c9lc00075e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cells in the body collectively sustain mechanical deformations in almost all physiological functions. From the morphogenesis stage, cells' ability to sustain stress is essential for the body's well-being. Several pathologies have been associated with abnormal mechanical properties, thus suggesting the Young's modulus as a biomarker to diagnose diseases and determine their progression. Advancements in the field are quite slow because current techniques for measuring cell and tissue mechanics rely on complex and bulky measurement platforms that have low repeatability rates and limited measurement time-scales. We present the first miniaturized system that allows accurate quantification of the Young's modulus of adherent cell monolayers over a longer time (1-2 days). Our approach is based on tensile testing and optical read-out. Thanks to a thoughtful design and material choice, we are able to miniaturize tensile testing platforms into a 1 cm × 2 cm device. We provide highly repeatable Young's modulus measurements in the relevant range between 3 kPa and 300 kPa, over time and under physiological conditions, thus representing an interesting alternative to existing measurement platforms. Furthermore, the compatibility with standard biological equipment, continuous optical imaging and measurements on all types of adherent cells make this device highly versatile. Measurements on human sarcoma osteogenic (SaOS2) and Madin-Darby canine kidney cells (MDCK) are reported. The demonstrated capability to measure real-time changes in mechanical properties, such as after chemical treatment, opens the door for investigating the effects of drugs on cell mechanics.
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Affiliation(s)
- Francesca Sorba
- Swiss Center for Electronics and Microtechnology, CSEM SA, Neuchâtel, Switzerland.
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Imboden M, de Coulon E, Poulin A, Dellenbach C, Rosset S, Shea H, Rohr S. High-speed mechano-active multielectrode array for investigating rapid stretch effects on cardiac tissue. Nat Commun 2019; 10:834. [PMID: 30783104 PMCID: PMC6381132 DOI: 10.1038/s41467-019-08757-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 01/24/2019] [Indexed: 11/25/2022] Open
Abstract
Systematic investigations of the effects of mechano-electric coupling (MEC) on cellular cardiac electrophysiology lack experimental systems suitable to subject tissues to in-vivo like strain patterns while simultaneously reporting changes in electrical activation. Here, we describe a self-contained motor-less device (mechano-active multielectrode-array, MaMEA) that permits the assessment of impulse conduction along bioengineered strands of cardiac tissue in response to dynamic strain cycles. The device is based on polydimethylsiloxane (PDMS) cell culture substrates patterned with dielectric actuators (DEAs) and compliant gold ion-implanted extracellular electrodes. The DEAs induce uniaxial stretch and compression in defined regions of the PDMS substrate at selectable amplitudes and with rates up to 18 s−1. Conduction along cardiomyocyte strands was found to depend linearly on static strain according to cable theory while, unexpectedly, being completely independent on strain rates. Parallel operation of multiple MaMEAs provides for systematic high-throughput investigations of MEC during spatially patterned mechanical perturbations mimicking in-vivo conditions. While strain is known to affect cardiac electrophysiology, experimental systems to interrogate the effect of rapid strain cycles on cardiac tissue are lacking. Here the authors introduce a multielectrode array that can induce rapid dynamic strain cycles on cardiomyocyte strands and see effects of strain amplitude but not strain rate on impulse conduction.
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Affiliation(s)
- Matthias Imboden
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland. .,Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
| | - Etienne de Coulon
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Alexandre Poulin
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Christian Dellenbach
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Samuel Rosset
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Herbert Shea
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Stephan Rohr
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
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Abstract
We present a mechanically active cell culture substrate that produces complex strain patterns and generates extremely high strain rates. The transparent miniaturized cell stretcher is compatible with live cell microscopy and provides a very compact and portable alternative to other systems. A cell monolayer is cultured on a dielectric elastomer actuator (DEA) made of a 30 μm thick silicone membrane sandwiched between stretchable electrodes. A potential difference of several kV’s is applied across the electrodes to generate electrostatic forces and induce mechanical deformation of the silicone membrane. The DEA cell stretcher we present here applies up to 38% tensile and 12% compressive strain, while allowing real-time live cell imaging. It reaches the set strain in well under 1 ms and generates strain rates as high as 870 s−1, or 87%/ms. With the unique capability to stretch and compress cells, our ultra-fast device can reproduce the rich mechanical environment experienced by cells in normal physiological conditions, as well as in extreme conditions such as blunt force trauma. This new tool will help solving lingering questions in the field of mechanobiology, including the strain-rate dependence of axonal injury and the role of mechanics in actin stress fiber kinetics.
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Abstract
This article presents the design, fabrication, and characterization of a soft biomimetic robotic fish based on dielectric elastomer actuators (DEAs) that swims by body and/or caudal fin (BCF) propulsion. BCF is a promising locomotion mechanism that potentially offers swimming at higher speeds and acceleration rates, and efficient locomotion. The robot consists of laminated silicone layers wherein two DEAs are used in an antagonistic configuration, generating undulating fish-like motion. The design of the robot is guided by a mathematical model based on the Euler–Bernoulli beam theory and takes account of the nonuniform geometry of the robot and of the hydrodynamic effect of water. The modeling results were compared with the experimental results obtained from the fish robot with a total length of 150 mm, a thickness of 0.75 mm, and weight of 4.4 g. We observed that the frequency peaks in the measured thrust force produced by the robot are similar to the natural frequencies computed by the model. The peak swimming speed of the robot was 37.2 mm/s (0.25 body length/s) at 0.75 Hz. We also observed that the modal shape of the robot at this frequency corresponds to the first natural mode. The swimming of the robot resembles real fish and displays a Strouhal number very close to those of living fish. These results suggest the high potential of DEA-based underwater robots relying on BCF propulsion, and applicability of our design and fabrication methods.
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Affiliation(s)
- Jun Shintake
- Institute of Microengineering Lausanne Campus, School of Engineering, Station 17, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vito Cacucciolo
- Institute of Microengineering Neuchâtel Campus, School of Engineering, École Polytechnique Fédérale de Lausanne, Neuchâtel, Switzerland
| | - Herbert Shea
- Institute of Microengineering Neuchâtel Campus, School of Engineering, École Polytechnique Fédérale de Lausanne, Neuchâtel, Switzerland
| | - Dario Floreano
- Institute of Microengineering Lausanne Campus, School of Engineering, Station 17, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Address correspondence to:Dario FloreanoInstitute of Microengineering Lausanne CampusSchool of Engineering, Station 17École Polytechnique Fédérale de LausanneLausanne 1015Switzerland
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Tang C, Li B, Zou C, Liu L, Chen H. Voltage-Induced Wrinkle Performance in a Hydrogel by Dielectric Elastomer Actuation. Polymers (Basel) 2018; 10:E697. [PMID: 30960622 PMCID: PMC6404066 DOI: 10.3390/polym10070697] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/14/2018] [Accepted: 06/19/2018] [Indexed: 11/19/2022] Open
Abstract
Hydrogel is a type of soft smart material and is responsive to stimuli. In the development of actuation in hydrogel, electrical actuation features a fast and universal strategy which is favored in the engineering system. Due to the difficulty in direct electrical actuation in hydrogel, in this study, an indirect actuation was attained via a dielectric elastomer. An aligned wrinkle pattern was obtained in the hydrogel upon a direct-current voltage, and it is reversible. The morphology and nonlinear mechanics of the electro-wrinkling deformation was characterized and analyzed. The optical property of the wrinkle in hydrogel was investigated, demonstrating a tunable blurring effect in optics. The electro-wrinkling performance offers a potential application with soft and tunable optical property in hydrogel-based actuators.
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Affiliation(s)
- Chao Tang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Bo Li
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
- Shaanxi Key Laboratory for Intelligent Robot, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Chenbang Zou
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Lei Liu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
- State Key Laboratory of Fluid Power and Mechanic Systems, Zhejiang University, Hangzhou 310027, China.
| | - Hualing Chen
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
- Shaanxi Key Laboratory for Intelligent Robot, Xi'an Jiaotong University, Xi'an 710049, China.
- State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an 710049, China.
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Buccarello A, Azzarito M, Michoud F, Lacour SP, Kucera JP. Uniaxial strain of cultured mouse and rat cardiomyocyte strands slows conduction more when its axis is parallel to impulse propagation than when it is perpendicular. Acta Physiol (Oxf) 2018; 223:e13026. [PMID: 29282897 DOI: 10.1111/apha.13026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/14/2017] [Accepted: 12/21/2017] [Indexed: 11/28/2022]
Abstract
AIM Cardiac tissue deformation can modify tissue resistance, membrane capacitance and ion currents and hence cause arrhythmogenic slow conduction. Our aim was to investigate whether uniaxial strain causes different changes in conduction velocity (θ) when the principal strain axis is parallel vs perpendicular to impulse propagation. METHODS Cardiomyocyte strands were cultured on stretchable custom microelectrode arrays, and θ was determined during steady-state pacing. Uniaxial strain (5%) with principal axis parallel (orthodromic) or perpendicular (paradromic) to propagation was applied for 1 minute and controlled by imaging a grid of markers. The results were analysed in terms of cable theory. RESULTS Both types of strain induced immediate changes of θ upon application and release. In material coordinates, orthodromic strain decreased θ significantly more (P < .001) than paradromic strain (2.2 ± 0.5% vs 1.0 ± 0.2% in n = 8 mouse cardiomyocyte cultures, 2.3 ± 0.4% vs 0.9 ± 0.5% in n = 4 rat cardiomyocyte cultures, respectively). The larger effect of orthodromic strain can be explained by the increase in axial myoplasmic resistance, which is not altered by paradromic strain. Thus, changes in tissue resistance substantially contributed to the changes of θ during strain, in addition to other influences (eg stretch-activated channels). Besides these immediate effects, the application of strain also consistently initiated a slow progressive decrease in θ and a slow recovery of θ upon release. CONCLUSION Changes in cardiac conduction velocity caused by acute stretch do not only depend on the magnitude of strain but also on its orientation relative to impulse propagation. This dependence is due to different effects on tissue resistance.
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Affiliation(s)
- A. Buccarello
- Department of Physiology; University of Bern; Bern Switzerland
| | - M. Azzarito
- Department of Physiology; University of Bern; Bern Switzerland
| | - F. Michoud
- Bertarelli Foundation Chair in Neuroprosthetic Technology; Laboratory for Soft Bioelectronic Interfaces; Institute of Microengineering; Institute of Bioengineering; Centre for Neuroprosthetics; École Polytechnique Fédérale de Lausanne (EPFL); Geneva Switzerland
| | - S. P. Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology; Laboratory for Soft Bioelectronic Interfaces; Institute of Microengineering; Institute of Bioengineering; Centre for Neuroprosthetics; École Polytechnique Fédérale de Lausanne (EPFL); Geneva Switzerland
| | - J. P. Kucera
- Department of Physiology; University of Bern; Bern Switzerland
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Rosset S, de Saint-Aubin C, Poulin A, Shea HR. Assessing the degradation of compliant electrodes for soft actuators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:105002. [PMID: 29092503 DOI: 10.1063/1.4989464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present an automated system to measure the degradation of compliant electrodes used in dielectric elastomer actuators (DEAs) over millions of cycles. Electrodes for DEAs generally experience biaxial linear strains of more than 10%. The decrease in electrode conductivity induced by this repeated fast mechanical deformation impacts the bandwidth of the actuator and its strain homogeneity. Changes in the electrode mechanical properties lead to reduced actuation strain. Rather than using an external actuator to periodically deform the electrodes, our measurement method consists of measuring the properties of an electrode in an expanding circle DEA. A programmable high voltage power supply drives the actuator with a square signal up to 1 kHz, periodically actuating the DEA, and thus stretching the electrodes. The DEA strain is monitored with a universal serial bus camera, while the resistance of the ground electrode is measured with a multimeter. The system can be used for any type of electrode. We validated the test setup by characterising a carbon black/silicone composite that we commonly use as compliant electrode. Although the composite is well-suited for tens of millions of cycles of actuation below 5%, we observe important degradation for higher deformations. When activated at a 20% radial strain, the electrodes suffer from important damage after a few thousand cycles, and an inhomogeneous actuation is observed, with the strain localised in a sub-region of the actuator only.
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Affiliation(s)
- Samuel Rosset
- École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | | | - Alexandre Poulin
- École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Herbert R Shea
- École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
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Marette A, Poulin A, Besse N, Rosset S, Briand D, Shea H. Flexible Zinc-Tin Oxide Thin Film Transistors Operating at 1 kV for Integrated Switching of Dielectric Elastomer Actuators Arrays. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1700880. [PMID: 28603892 DOI: 10.1002/adma.201700880] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/26/2017] [Indexed: 05/19/2023]
Abstract
Flexible high-voltage thin-film transistors (HVTFTs) operating at more than 1 kV are integrated with compliant dielectric elastomer actuators (DEA) to create a flexible array of 16 independent actuators. To allow for high-voltage operation, the HVTFT implements a zinc-tin oxide channel, a thick dielectric stack, and an offset gate. At a source-drain bias of 1 kV, the HVTFT has a 20 µA on-current at a gate voltage bias of 30 V. Their electrical characteristics enable the switching of DEAs which require drive voltages of over 1 kV, making control of an array simpler in comparison to the use of external high-voltage switching. These HVTFTs are integrated in a flexible haptic display consisting of a 4 × 4 matrix of DEAs and HVTFTs. Using a single 1.4 kV supply, each DEA is independently switched by its associated HVTFT, requiring only a 30 V gate voltage for full DEA deflection. The 4 × 4 display operates well even when bent to a 5 mm radius of curvature. By enabling DEA switching at low voltages, flexible metal-oxide HVTFTs enable complex flexible systems with dozens to hundreds of independent DEAs for applications in haptics, Braille displays, and soft robotics.
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Affiliation(s)
- Alexis Marette
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
| | - Alexandre Poulin
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
| | - Nadine Besse
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
| | - Samuel Rosset
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
| | - Danick Briand
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
| | - Herbert Shea
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000, Neuchâtel, Switzerland
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Abstract
In vivo, cells of the vascular system are subjected to various mechanical stimuli and have demonstrated the ability to adapt their behavior via mechanotransduction. Recent advances in microfluidic and "on-chip" techniques have provided the technology to study these alterations in cell behavior. Contrary to traditional in vitro assays such as transwell plates and parallel plate flow chambers, these microfluidic devices (MFDs) provide the opportunity to integrate multiple mechanical cues (e.g. shear stress, confinement, substrate stiffness, vessel geometry and topography) with in situ quantification capabilities. As such, MFDs can be used to recapitulate the in vivo mechanical setting and systematically vary microenvironmental conditions for improved mechanobiological studies of the endothelium. Additionally, adequate modelling provides for enhanced understanding of disease progression, design of cell separation and drug delivery systems, and the development of biomaterials for tissue engineering applications. Here, we will discuss the advances in knowledge about endothelial cell mechanosensing resulting from the design and application of biomimetic on-chip and microfluidic platforms.
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Cei D, Costa J, Gori G, Frediani G, Domenici C, Carpi F, Ahluwalia A. A bioreactor with an electro-responsive elastomeric membrane for mimicking intestinal peristalsis. BIOINSPIRATION & BIOMIMETICS 2016; 12:016001. [PMID: 27918289 DOI: 10.1088/1748-3190/12/1/016001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
This study describes an actuated bioreactor which mimics the pulsatile contractile motion of the intestinal barrier using electro-responsive elastomers as smart materials that undergo deformation upon electrical stimulation. The device consists of an annular dielectric elastomer actuator working as a radial artificial muscle able to rhythmically contract and relax a central cell culture well. The bioreactor maintained up to 4 h of actuation at a frequency of 0.15 Hz and a strain of 8%-10%, to those of the cyclic contraction and relaxation of the small intestine. In vitro tests demonstrated that the device was biocompatible and cell-adhesive for Caco-2 cells, which formed a confluent monolayer following 21 days of culture in the central well. In addition, cellular adhesion and cohesion were maintained after 4 h of continuous cyclic strain. These preliminary results encourage further investigations on the use of dielectric elastomer actuation as a versatile technology that might overcome the limitations of commercially available pneumatic driving systems to obtain bioreactors that can cyclically deform cell cultures in a biomimetic fashion.
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Affiliation(s)
- Daniele Cei
- Research Center 'E.Piaggio' and Department of Information Engineering, University of Pisa, Largo L Lazzarino, I-56126 Pisa, Italy
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