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Lee KY, Loh HX, Wan ACA. Systems for Muscle Cell Differentiation: From Bioengineering to Future Food. MICROMACHINES 2021; 13:71. [PMID: 35056236 PMCID: PMC8777594 DOI: 10.3390/mi13010071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/24/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022]
Abstract
In light of pressing issues, such as sustainability and climate change, future protein sources will increasingly turn from livestock to cell-based production and manufacturing activities. In the case of cell-based or cultured meat a relevant aspect would be the differentiation of muscle cells into mature muscle tissue, as well as how the microsystems that have been developed to date can be developed for larger-scale cultures. To delve into this aspect we review previous research that has been carried out on skeletal muscle tissue engineering and how various biological and physicochemical factors, mechanical and electrical stimuli, affect muscle cell differentiation on an experimental scale. Material aspects such as the different biomaterials used and 3D vs. 2D configurations in the context of muscle cell differentiation will also be discussed. Finally, the ability to translate these systems to more scalable bioreactor configurations and eventually bring them to a commercial scale will be touched upon.
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Affiliation(s)
| | | | - Andrew C. A. Wan
- Singapore Institute of Food and Biotechnology Innovation, 31 Biopolis Way, #01-02, Nanos, Singapore 138669, Singapore; (K.-Y.L.); (H.-X.L.)
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Collagen Film Activation with Nanoscale IKVAV-Capped Dendrimers for Selective Neural Cell Response. NANOMATERIALS 2021; 11:nano11051157. [PMID: 33925197 PMCID: PMC8146934 DOI: 10.3390/nano11051157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
Biocompatible neural guidance conduits are alternatives to less abundant autologous tissue grafts for small nerve gap injuries. To address larger peripheral nerve injuries, it is necessary to design cell selective biomaterials that attract neuronal and/or glial cells to an injury site while preventing the intrusion of fibroblasts that cause inhibitory scarring. Here, we investigate a potential method for obtaining this selective cellular response by analysing the responses of rat Schwann cells and human dermal fibroblasts to isoleucine-lysine-valine-alanine-valine (IKVAV)-capped dendrimer-activated collagen films. A high quantity of nanoscale IKVAV-capped dendrimers incorporated onto pre-crosslinked collagen films promoted rat Schwann cell attachment and proliferation, and inhibited human dermal fibroblast proliferation. In addition, while pre-crosslinked dendrimer-activated films inhibited fibroblast proliferation, non-crosslinked dendrimer-activated films and films that were crosslinked after dendrimer-activation (post-crosslinked films) did not. The different cellular responses to pre-crosslinked and post-crosslinked films highlight the importance of having fully exposed, non-covalently bound biochemical motifs (pre-crosslinked films) directing certain cellular responses. These results also suggest that high concentrations of nanoscale IKVAV motifs can inhibit fibroblast attachment to biological substrates, such as collagen, which inherently attract fibroblasts. Therefore, this work points toward the potential of IKVAV-capped dendrimer-activated collagen biomaterials in limiting neuropathy caused by fibrotic scarring at peripheral nerve injury sites.
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Ruiter FAA, Sidney LE, Kiick KL, Segal JI, Alexander C, Rose FRAJ. The electrospinning of a thermo-responsive polymer with peptide conjugates for phenotype support and extracellular matrix production of therapeutically relevant mammalian cells. Biomater Sci 2021; 8:2611-2626. [PMID: 32239020 DOI: 10.1039/c9bm01965k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Current cell expansion methods for tissue engineering and regenerative medicine applications rely on the use of enzymatic digestion passaging and 2D platforms. However, this enzymatic treatment significantly reduces cell quality, due to the destruction of important cell-surface proteins. In addition, culture in 2D results in undesired de-differentiation of the cells caused by the lack of 3D similarity to the natural extracellular matrix (ECM) environment. Research has led to the development of thermo-responsive surfaces for the continuous culture of cells. These thermo-responsive materials properties can be used to passage cells from the surface when the cell culture temperature is reduced. Here we report the development of a PLA/thermo-responsive (PDEGMA) blend 3D electrospun fibre-based scaffold to create an enzymatic-free 3D cell culture platform for the expansion of mammalian cells with the desired phenotype for clinical use. Human corneal stromal cells (hCSCs) were used as an exemplar as they have been observed to de-differentiate to an undesirable myo-fibroblastic phenotype when cultured by conventional 2D cell culture methods. Scaffolds were functionalised with a cell adherence peptide sequence GGG-YIGSR by thiol-ene chemistry to improve cell adherence and phenotype support. This was obtained by functionalising the thermo-responsive polymer with a thiol (PDEGMA/PDEGSH) by co-polymerisation. These incorporated thiols react with the norbornene acid functionalised peptide (Nor-GGG-YIGSR) under UV exposure. Presence of the thiol in the scaffold and subsequent peptide attachment on the scaffolds were confirmed by fluorescence labelling, ToF-SIMS and XPS analysis. The biocompatibility of the peptide containing scaffolds was assessed by the adhesion, proliferation and immuno-staining of hCSCs. Significant increase in hCSC adherence and proliferation was observed on the peptide containing scaffolds. Immuno-staining showed maintained expression of the desired phenotypic markers ALDH, CD34 and CD105, while showing no or low expression of the undesired phenotype marker α-SMA. This desired expression was observed to be maintained after thermo-responsive passaging and higher when cells were cultured on PLA scaffolds with 10 wt% PDEGMA/4 mol% PDEGS-Nor-GGG-YIGSR. This paper describes the fabrication and application of a first generation, biocompatible peptide conjugated thermo-responsive fibrous scaffold. The ease of fabrication, successful adherence and expansion of a therapeutically relevant cell type makes these scaffolds a promising new class of materials for the application of cell culture expansion platforms in the biomaterials and tissue engineering field.
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Affiliation(s)
- F A A Ruiter
- School of Pharmacy, University of Nottingham, UK.
| | - L E Sidney
- Division of Clinical Neuroscience, University of Nottingham, UK.
| | - K L Kiick
- Department of Material Science and Engineering, University of Delaware, USA.
| | - J I Segal
- Faculty of Engineering, University of Nottingham, UK.
| | - C Alexander
- School of Pharmacy, University of Nottingham, UK.
| | - F R A J Rose
- School of Pharmacy, University of Nottingham, UK.
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Kanjevac T, Gustafson C, Ivanovska A, Ravanetti F, Cacchioli A, Bosnakovski D. Inflammatory Cytokines and Biodegradable Scaffolds in Dental Mesenchymal Stem Cells Priming. Curr Stem Cell Res Ther 2019; 14:320-326. [PMID: 30608044 DOI: 10.2174/1574888x14666190103170109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 10/15/2018] [Accepted: 11/02/2018] [Indexed: 02/06/2023]
Abstract
Mesenchymal stem cells (MSCs) are multipotent stem cells with wide-ranging clinical applications due to their ability to regenerate tissue from mesenchymal origin and their capability of suppressing immune responses, thus reducing the likelihood of graft versus host disease after transplantation. MSCs can be isolated from a variety of sources including bone marrow, adipose tissue, umbilical cord blood, and immature teeth. Dental stem cells (DSCs) possess progenitor and immunomodulatory abilities as the other MSC types and because they can be easily isolated, are considered as attractive therapeutic agents in regenerative dentistry. Recently, it has been shown that DSCs seeded onto newly developed synthetic biomaterial scaffolds have retained their potential for proliferation and at the same time have enhanced capabilities for differentiation and immunosuppression. The scaffolds are becoming more efficient at MSC priming as researchers learn how short peptide sequences alter the adhesive and proliferative capabilities of the scaffolds by stimulating or inhibiting classical osteogenic pathways. New findings on how to modulate the inflammatory microenvironment, which can prime DSCs for differentiation, combined with the use of next generation scaffolds may significantly improve their therapeutic potential. In this review, we summarize current findings regarding DSCs as a potential regenerative therapy, including stem cell priming with inflammatory cytokines, types of scaffolds currently being explored and the modulation of scaffolds to regulate immune response and promote growth.
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Affiliation(s)
- Tatjana Kanjevac
- Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Collin Gustafson
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, United States
| | - Ana Ivanovska
- Department of Veterinary Science, University of Parma, Parma, Italy
| | | | | | - Darko Bosnakovski
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, United States.,Faculty of Medical Sciences, University Goce Delcev, Stip, R. Macedonia
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5
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Mitropoulos AN, Marelli B, Ghezzi CE, Applegate MB, Partlow BP, Kaplan DL, Omenetto FG. Transparent, Nanostructured Silk Fibroin Hydrogels with Tunable Mechanical Properties. ACS Biomater Sci Eng 2015; 1:964-970. [PMID: 33429527 DOI: 10.1021/acsbiomaterials.5b00215] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Silk fibroin from the Bombyx mori caterpillar has been processed into many material forms, with potential applications in areas ranging from optoelectronics to tissue engineering. As a hydrogel, silk fibroin has been engineered as a substrate for the regeneration of soft tissues where hydration and mechanical compatibility are necessary. Current fabrication of silk fibroin hydrogels produces microstructured materials that lack transparency and limits the ability to fully exploit the hydrogel form. Transparency is the main characteristic of some human tissues (e.g., cornea) where silk fibroin in the film format has shown potential as scaffolding material, however, lacking the necessary hydration and successful attachment of cells without biochemical functionalization. Additionally, detection using light is an important method to translate information for instruction, sensing, and visualization of biological entities and light sensitive molecules. Here, we introduce a method for the fabrication of transparent silk hydrogels by driving the formation of nanostructures in the silk fibroin material. These nanostructures are formed by exposing silk solution (concentration below 15 mg/mL) to organic solvents that induce the amorphous to crystalline transition of the protein and indeed the sol-gel transition of the material. We have also explored a process to modulate the mechanical properties of silk fibroin hydrogel within the physiological range by controlling the amount of metal ions present in the protein structure. Nanostructured silk fibroin hydrogels are biocompatible and allow for attachment and proliferation of human dermal fibroblasts without any biochemical functionalization. In addition, seeding of human cornea epithelial cells (HCECs) on the hydrogel surface results in the formation of an epithelium, which does not alter the gels' transparency and shows biological properties that challenge the performances of HCECs seeded in collagen hydrogels, the current standard material for the engineering of corneal tissue.
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Affiliation(s)
- Alexander N Mitropoulos
- Department of Biomedical Engineering and §Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Benedetto Marelli
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Chiara E Ghezzi
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Matthew B Applegate
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Benjamin P Partlow
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - David L Kaplan
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Fiorenzo G Omenetto
- Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
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Damodaran G, Syed M, Leigh I, Myers S, Navsaria H. Clinical application of skin substitutes. ACTA ACUST UNITED AC 2014. [DOI: 10.1586/17469872.3.3.345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Teichmann J, Valtink M, Nitschke M, Gramm S, Funk RHW, Engelmann K, Werner C. Tissue engineering of the corneal endothelium: a review of carrier materials. J Funct Biomater 2013; 4:178-208. [PMID: 24956190 PMCID: PMC4030930 DOI: 10.3390/jfb4040178] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 09/13/2013] [Accepted: 09/24/2013] [Indexed: 12/13/2022] Open
Abstract
Functional impairment of the human corneal endothelium can lead to corneal blindness. In order to meet the high demand for transplants with an appropriate human corneal endothelial cell density as a prerequisite for corneal function, several tissue engineering techniques have been developed to generate transplantable endothelial cell sheets. These approaches range from the use of natural membranes, biological polymers and biosynthetic material compositions, to completely synthetic materials as matrices for corneal endothelial cell sheet generation. This review gives an overview about currently used materials for the generation of transplantable corneal endothelial cell sheets with a special focus on thermo-responsive polymer coatings.
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Affiliation(s)
- Juliane Teichmann
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Institute of Biofunctional Polymer Materials, Hohe Straße 6, Dresden 01069, Germany.
| | - Monika Valtink
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, Dresden 01307, Germany.
| | - Mirko Nitschke
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Institute of Biofunctional Polymer Materials, Hohe Straße 6, Dresden 01069, Germany.
| | - Stefan Gramm
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Institute of Biofunctional Polymer Materials, Hohe Straße 6, Dresden 01069, Germany.
| | - Richard H W Funk
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, Dresden 01307, Germany.
| | - Katrin Engelmann
- CRTD/DFG-Center for Regenerative Therapies Dresden-Cluster of Excellence, Fetscherstraße 105, Dresden 01307, Germany.
| | - Carsten Werner
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Institute of Biofunctional Polymer Materials, Hohe Straße 6, Dresden 01069, Germany.
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Xiao X, Pan S, Liu X, Zhu X, Connon CJ, Wu J, Mi S. In vivo study of the biocompatibility of a novel compressed collagen hydrogel scaffold for artificial corneas. J Biomed Mater Res A 2013; 102:1782-7. [PMID: 23813783 DOI: 10.1002/jbm.a.34848] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/08/2013] [Accepted: 06/11/2013] [Indexed: 12/13/2022]
Abstract
The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea.
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Affiliation(s)
- Xianghua Xiao
- Shaanxi Institute of Ophthalmology, Xi'an, Shaanxi, 710002, People's Republic of China; Shaanxi Key Laboratory of Eye, Xi'an, Shaanxi, 710002, People's Republic of China; Xi'an First Hospital, Xi'an, Shaanxi, 710002, People's Republic of China
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Princz M, Sheardown H. Heparin-modified dendrimer crosslinked collagen matrices for the delivery of heparin-binding epidermal growth factor. J Biomed Mater Res A 2012; 100:1929-37. [DOI: 10.1002/jbm.a.34128] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 01/23/2023]
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Princz MA, Sheardown H. Modified dendrimer cross-linked collagen-based matrices. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2011; 23:2207-22. [PMID: 22137239 DOI: 10.1163/156856211x612736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Dendrimer cross-linking has been achieved with pepsin digested over 80% type-I bovine collagen to create strong hydrogels with good cell compatibility. Herein we investigate the use of commercially available collagen-based products with the dendrimer cross-linking technology. Specifically PureCol(®) (PC), a 97% bovine type-I collagen, human collagen (HC) and human extracellular matrix (hECM) were concentrated, and then cross-linked with polypropyleneimine octaamine generation two dendrimers using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) chemistry. PC gels with 30 and 20 mg/ml bovine collagen were fabricated, and despite similar concentrations to >80% type-I bovine collagen dendrimer cross-linked gels (CG), PC gels demonstrated increased swelling and decreased stability, as determined with collagenase digestion. The highly purified bovine (PC) and human sourced-collagen (HC) gels were similar in performance, but not as stable as the CG gels, which may correlate to the manufacturer's collagen purification and storage. Finally, the addition of hECM components to PC to create PC-hECM gels, resulted in a looser gel network, compared to heparinized dendrimer cross- linked bovine >80% type-I collagen gels (CHG). However, all collagen-based gels supported 3T3 fibroblast cell growth over 4 days, indicating these gels may be suitable for tissue-engineering applications.
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Affiliation(s)
- M A Princz
- a Department of Chemical Engineering , McMaster University , 1280 Main Street W. , Hamilton , ON , Canada , L8S 4L8
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Sreejalekshmi KG, Nair PD. Biomimeticity in tissue engineering scaffolds through synthetic peptide modifications-altering chemistry for enhanced biological response. J Biomed Mater Res A 2010; 96:477-91. [PMID: 21171167 DOI: 10.1002/jbm.a.32980] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 06/09/2010] [Indexed: 12/16/2022]
Abstract
Biomimetic and bioactive biomaterials are desirable as tissue engineering scaffolds by virtue of their capability to mimic natural environments of the extracellular matrix. Biomimeticity has been achieved by the incorporation of synthetic short peptide sequences into suitable materials either by surface modification or by bulk incorporation. Research in this area has identified several novel synthetic peptide segments, some of them with cell-specific interactions, which may serve as potential candidates for use in explicit tissue applications. This review focuses on the developments and prospective directions of incorporating short synthetic peptide sequences onto scaffolds for tissue engineering, with emphasis on the chemistry of peptide immobilization and subsequent cell responses toward modified scaffolds. The article provides a decision-tree-type flow chart indicating the most probable cellular events on a given peptide-modified scaffold along with the consolidated list of synthetic peptide sequences, supports as well as cell types used in various tissue engineering studies, and aims to serve as a quick reference guide to peptide chemists and material scientists interested in the field.
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Affiliation(s)
- Kumaran G Sreejalekshmi
- Division of Tissue Engineering and Regeneration Technologies, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Satelmond Palace, Poojapura, Thiruvananthapuram 695 012, Kerala, India, India.
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Ex Vivo Construction of an Artificial Ocular Surface by Combination of Corneal Limbal Epithelial Cells and a Compressed Collagen Scaffold Containing Keratocytes. Tissue Eng Part A 2010; 16:2091-100. [DOI: 10.1089/ten.tea.2009.0748] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Kim A, Lakshman N, Karamichos D, Petroll WM. Growth factor regulation of corneal keratocyte differentiation and migration in compressed collagen matrices. Invest Ophthalmol Vis Sci 2010; 51:864-75. [PMID: 19815729 PMCID: PMC2819331 DOI: 10.1167/iovs.09-4200] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 09/03/2009] [Accepted: 09/16/2009] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To evaluate a novel 3D culture model of the corneal stroma and apply it to investigate how key wound-healing growth factors regulate the mechanics of corneal keratocyte migration. METHODS Rabbit corneal keratocytes were seeded within collagen matrices that were compacted using external compression. Six-millimeter-diameter buttons were then incubated in media supplemented with 10% FBS, TGFbeta1, TGFbeta2, platelet-derived growth factor (PDGF), or no growth factor (control). After 1, 3, or 7 days, matrices were labeled with phalloidin and a nucleic acid dye, and were imaged using laser confocal microscopy. To study cell migration, buttons were nested within acellular uncompressed outer collagen matrices before growth factor stimulation. RESULTS Corneal keratocytes in basal media within compressed matrices had a broad, convoluted cell body and thin dendritic processes. In contrast, cells in 10% FBS developed a bipolar fibroblastic morphology. Treatment with TGFbeta induced the formation of stress fibers expressing alpha-smooth muscle actin, suggesting myofibroblast transformation. PDGF induced keratocyte elongation without inducing stress fiber formation. Both 10% FBS and PDGF stimulated significant keratocyte migration through the uncompressed outer matrix, but 10% FBS produced more cell-induced collagen matrix reorganization. TGFbeta induced the smallest increase in migration and the greatest matrix reorganization. CONCLUSIONS Corneal keratocytes are able to differentiate normally and respond to growth factors within compressed collagen matrices, which provide a high-stiffness, 3D environment, similar to native stromal tissue. In addition, nesting these matrices provides a unique platform for investigating the mechanics of keratocyte migration after exposure to specific wound-healing cytokines.
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Affiliation(s)
- Areum Kim
- From the Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Neema Lakshman
- From the Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Dimitris Karamichos
- From the Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - W. Matthew Petroll
- From the Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
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Sitalakshmi G, Sudha B, Madhavan HN, Vinay S, Krishnakumar S, Mori Y, Yoshioka H, Abraham S. Ex vivo cultivation of corneal limbal epithelial cells in a thermoreversible polymer (Mebiol Gel) and their transplantation in rabbits: an animal model. Tissue Eng Part A 2009; 15:407-15. [PMID: 18724830 DOI: 10.1089/ten.tea.2008.0041] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We evaluated the efficacy of autologous expanded corneal epithelial cell transplants derived from harvested limbal biopsy cultured on a thermoreversible polymer (Mebiol Gel) for the management of unilateral limbal stem cell deficiency (LSCD). Corneal limbal biopsies from 12 rabbits were cultured on a thermoreversible polymer Mebiol Gel at 37 degrees C. Cells were harvested from the dishes after 3 weeks by reducing temperature to 4 degrees C. Autologous transplantation was undertaken to reconstruct the experimentally induced limbal stem cell deficiency in the rabbit eyes. The corneas of both eyes of all rabbits were harvested later for molecular studies. Reparative surgery was a total success in seven rabbits, partial success in two, and failure in three eyes. Histology of the seven successful eyes showed the successful growth of the corneal epithelium. Immunohistochemistry and reverse transcriptase polymerase chain reaction showed the cornea phenotype and stem cell-associated markers in the limbus of the seven successful eyes, indicating the homing of these cells into limbus. In the three failure cases and in the two control rabbit eyes, used in the study, histology showed presence of goblet cells and vascularization in the stroma with abortive formation of corneal epithelium. Our results suggest that transplantation of autologous limbal epithelial cells grown in thermoreversible polymer Mebiol Gel may restore a nearly normal ocular epithelial surface in eyes with unilateral LSCD.
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Affiliation(s)
- G Sitalakshmi
- Department of Cornea, Vision Research Foundation, Chennai, India
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Tiong WHC, Damodaran G, Naik H, Kelly JL, Pandit A. Enhancing amine terminals in an amine-deprived collagen matrix. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11752-11761. [PMID: 18774827 DOI: 10.1021/la801913c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.
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Affiliation(s)
- William H C Tiong
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Republic of Ireland
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