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Evaluating the clinical translational relevance of animal models for limbal stem cell deficiency: A systematic review. Ocul Surf 2021; 23:169-183. [PMID: 34583088 DOI: 10.1016/j.jtos.2021.09.006] [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] [Received: 06/07/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Animal models are pivotal for elucidating pathophysiological mechanisms and evaluating novel therapies. This systematic review identified studies that developed or adapted animal models of limbal stem cell deficiency (LSCD), assessed their reporting quality, summarized their key characteristics, and established their clinical translational relevance to human disease. METHODS The protocol was prospectively registered (PROSPERO CRD42020203937). Searches were conducted in PubMed, Ovid EMBASE and Web of Science in August 2020. Two authors screened citations, extracted data, assessed the reporting quality of eligible studies using the ARRIVE guidelines, and judged the clinical translational relevance of each model using a custom matrix. RESULTS 105 studies were included. Rabbits were the most common animal species. Overall, 97% of studies recapitulated LSCD to a clinical etiology, however 62% did not provide sufficient methodological detail to enable independent reproduction of the model. Adverse events and/or exclusion of animals were infrequently (20%) reported. Approximately one-quarter of studies did not produce the intended severity of LSCD; 34% provided insufficient information to assess the fidelity of disease induction. Adjunctive diagnostic confirmation of LSCD induction was performed in 13% of studies. CONCLUSIONS This is the first systematic review to assess the reporting quality and clinical translational relevance of animal models of LSCD. Models of LSCD have evolved over time, resulting in variable reporting of the characteristics of animals, experimental procedures and adverse events. In most studies, validation of LSCD was made using clinical tests; newer adjunctive techniques would enhance diagnostic validation. As most studies sought to evaluate novel therapies for LSCD, animal models should ideally recapitulate all features of the condition that develop in patients.
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Kennedy S, Lace R, Carserides C, Gallagher AG, Wellings DA, Williams RL, Levis HJ. Poly-ε-lysine based hydrogels as synthetic substrates for the expansion of corneal endothelial cells for transplantation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2019; 30:102. [PMID: 31485761 PMCID: PMC6726667 DOI: 10.1007/s10856-019-6303-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Dysfunction of the corneal endothelium (CE) resulting from progressive cell loss leads to corneal oedema and significant visual impairment. Current treatments rely upon donor allogeneic tissue to replace the damaged CE. A donor cornea shortage necessitates the development of biomaterials, enabling in vitro expansion of corneal endothelial cells (CECs). This study investigated the use of a synthetic peptide hydrogel using poly-ε-lysine (pεK), cross-linked with octanedioic-acid as a potential substrate for CECs expansion and CE grafts. PεK hydrogel properties were optimised to produce a substrate which was thin, transparent, porous and robust. A human corneal endothelial cell line (HCEC-12) attached and grew on pεK hydrogels as confluent monolayers after 7 days, whereas primary porcine CECs (pCECs) detached from the pεK hydrogel. Pre-adsorption of collagen I, collagen IV and fibronectin to the pεK hydrogel increased pCEC adhesion at 24 h and confluent monolayers formed at 7 days. Minimal cell adhesion was observed with pre-adsorbed laminin, chondroitin sulphate or commercial FNC coating mix (fibronectin, collagen and albumin). Functionalisation of the pεK hydrogel with synthetic cell binding peptide H-Gly-Gly-Arg-Gly-Asp-Gly-Gly-OH (RGD) or α2β1 integrin recognition sequence H-Asp-Gly-Glu-Ala-OH (DGEA) resulted in enhanced pCEC adhesion with the RGD peptide only. pCECs grown in culture at 5 weeks on RGD pεK hydrogels showed zonula occludins 1 staining for tight junctions and expression of sodium-potassium adenosine triphosphase, suggesting a functional CE. These results demonstrate the pεK hydrogel can be tailored through covalent binding of RGD to provide a surface for CEC attachment and growth. Thus, providing a synthetic substrate with a therapeutic application for the expansion of allogenic CECs and replacement of damaged CE.
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Affiliation(s)
- Stephnie Kennedy
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - Rebecca Lace
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - Constandinos Carserides
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - Andrew G Gallagher
- SpheriTech Ltd, Business and Technical Park, The Heath, Runcorn, WA7 4QX, UK
| | - Donald A Wellings
- SpheriTech Ltd, Business and Technical Park, The Heath, Runcorn, WA7 4QX, UK
| | - Rachel L Williams
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Hannah J Levis
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK
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Chen Z, You J, Liu X, Cooper S, Hodge C, Sutton G, Crook JM, Wallace GG. Biomaterials for corneal bioengineering. ACTA ACUST UNITED AC 2018; 13:032002. [PMID: 29021411 DOI: 10.1088/1748-605x/aa92d2] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Corneal transplantation is an important surgical treatment for many common corneal diseases. However, a worldwide shortage of tissue from suitable corneal donors has meant that many people are not able to receive sight-restoring operations. In addition, rejection is a major cause of corneal transplant failure. Bioengineering corneal tissue has recently gained widespread attention. In order to facilitate corneal regeneration, a range of materials is currently being investigated. The ideal substrate requires sufficient tectonic durability, biocompatibility with cultured cellular elements, transparency, and perhaps biodegradability and clinical compliance. This review considers the anatomy and function of the native cornea as a precursor to evaluating a variety of biomaterials for corneal regeneration including key characteristics for optimal material form and function. The integration of appropriate cells with the most appropriate biomaterials is also discussed. Taken together, the information provided offers insight into the requirements for fabricating synthetic and semisynthetic corneas for in vitro modeling of tissue development and disease, pharmaceutical screening, and in vivo application for regenerative medicine.
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Affiliation(s)
- Zhi Chen
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, AIIM Facility, Innovation Campus, University of Wollongong, Squires Way, Fairy Meadow, New South Wales 2519, Australia
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Hazra S, Nandi S, Naskar D, Guha R, Chowdhury S, Pradhan N, Kundu SC, Konar A. Non-mulberry Silk Fibroin Biomaterial for Corneal Regeneration. Sci Rep 2016; 6:21840. [PMID: 26908015 PMCID: PMC4764817 DOI: 10.1038/srep21840] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 01/27/2016] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Successful repair of a damaged corneal surface is a great challenge and may require the use of a scaffold that supports cell growth and differentiation. Amniotic membrane is currently used for this purpose, in spite of its limitations. A thin transparent silk fibroin film from non-mulberry Antheraea mylitta (Am) has been developed which offers to be a promising alternative. The silk scaffolds provide sufficient rigidity for easy handling, the scaffolds support the sprouting, migration, attachment and growth of epithelial cells and keratocytes from rat corneal explants; the cells form a cell sheet, preserve their phenotypes, express cytokeratin3 and vimentin respectively. The films also support growth of limbal stem cell evidenced by expression of ABCG2. The cell growth on the silk film and the amniotic membrane is comparable. The implanted film within the rabbit cornea remains transparent, stable. The clinical examination as well as histology shows absence of any inflammatory response or neovascularization. The corneal surface integrity is maintained; tear formation, intraocular pressure and electroretinography of implanted eyes show no adverse changes. The silk fibroin film from non-mulberry silk worms may be a worthy candidate for use as a corneal scaffold.
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Affiliation(s)
- Sarbani Hazra
- Department of Veterinary Surgery & Radiology, West Bengal University of Animal & Fishery Sciences, Kolkata-700037, West Bengal, India
| | - Sudip Nandi
- CSIR-Indian Institute of Chemical Biology, Kolkata-700032, West Bengal, India
| | - Deboki Naskar
- Department of Biotechnology, Indian Institute of Technology, Kharagpur, Kharagpur-721302, West Bengal, India
| | - Rajdeep Guha
- CSIR-Indian Institute of Chemical Biology, Kolkata-700032, West Bengal, India
| | - Sushovan Chowdhury
- CSIR-Indian Institute of Chemical Biology, Kolkata-700032, West Bengal, India
| | - Nirparaj Pradhan
- Department of Veterinary Surgery & Radiology, West Bengal University of Animal & Fishery Sciences, Kolkata-700037, West Bengal, India
| | - Subhas C. Kundu
- Department of Biotechnology, Indian Institute of Technology, Kharagpur, Kharagpur-721302, West Bengal, India
| | - Aditya Konar
- CSIR-Indian Institute of Chemical Biology, Kolkata-700032, West Bengal, India
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An Ultra-thin Amniotic Membrane as Carrier in Corneal Epithelium Tissue-Engineering. Sci Rep 2016; 6:21021. [PMID: 26876685 PMCID: PMC4753477 DOI: 10.1038/srep21021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/14/2016] [Indexed: 12/21/2022] Open
Abstract
Amniotic membranes (AMs) are widely used as a corneal epithelial tissue carrier in reconstruction surgery. However, the engineered tissue transparency is low due to the translucent thick underlying AM stroma. To overcome this drawback, we developed an ultra-thin AM (UAM) by using collagenase IV to strip away from the epithelial denuded AM (DAM) some of the stroma. By thinning the stroma to about 30 μm, its moist and dry forms were rendered acellular, optically clear and its collagen framework became compacted and inerratic. Engineered rabbit corneal epithelial cell (RCEC) sheets generated through expansion of limbal epithelial cells on UAM were more transparent and thicker than those expanded on DAM. Moreover, ΔNp63 and ABCG2 gene expression was greater in tissue engineered cell sheets expanded on UAM than on DAM. Furthermore, 2 weeks after surgery, the cornea grafted with UAM based cell sheets showed higher transparency and more stratified epithelium than the cornea grafted with DAM based cell sheets. Taken together, tissue engineered corneal epithelium generated on UAM has a preferable outcome because the transplanted tissue is more transparent and better resembles the phenotype of the native tissue than that obtained by using DAM for this procedure. UAM preserves compact layer of the amniotic membrane and maybe an ideal substrate for corneal epithelial tissue engineering.
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Limbal Stem Cell Deficiency: Current Treatment Options and Emerging Therapies. Stem Cells Int 2015; 2016:9798374. [PMID: 26788074 PMCID: PMC4691643 DOI: 10.1155/2016/9798374] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/18/2015] [Indexed: 12/15/2022] Open
Abstract
Severe ocular surface disease can result in limbal stem cell deficiency (LSCD), a condition leading to decreased visual acuity, photophobia, and ocular pain. To restore the ocular surface in advanced stem cell deficient corneas, an autologous or allogenic limbal stem cell transplantation is performed. In recent years, the risk of secondary LSCD due to removal of large limbal grafts has been significantly reduced by the optimization of cultivated limbal epithelial transplantation (CLET). Despite the great successes of CLET, there still is room for improvement as overall success rate is 70% and visual acuity often remains suboptimal after successful transplantation. Simple limbal epithelial transplantation reports higher success rates but has not been performed in as many patients yet. This review focuses on limbal epithelial stem cells and the pathophysiology of LSCD. State-of-the-art therapeutic management of LSCD is described, and new and evolving techniques in ocular surface regeneration are being discussed, in particular, advantages and disadvantages of alternative cell scaffolds and cell sources for cell based ocular surface reconstruction.
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Nam E, Fujita N, Morita M, Tsuzuki K, Lin HY, Chung CS, Nakagawa T, Nishimura R. Comparison of the canine corneal epithelial cell sheets cultivated from limbal stem cells on canine amniotic membrane, atelocollagen gel, and temperature-responsive culture dish. Vet Ophthalmol 2015; 18:317-25. [PMID: 25495909 DOI: 10.1111/vop.12241] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The current study compared canine corneal epithelial cell sheets cultivated from limbal stem cells on amniotic membrane, atelocollagen gel, and temperature-responsive culture dish. PROCEDURES We collected limbal epithelial cells from the intact eyes of beagles and cultivated the cells on denuded canine amniotic membranes, temperature-responsive cell culture labware, and collagen gel with 3T3 feeder cells. Immunofluorescence staining for Ki-67 was used to analyze the capacity of cell proliferation in the sheets. Immunofluorescence staining was also performed for the corneal epithelium-specific marker cytokeratin 3 and putative stem cell markers ABCG2 and p63. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to detect ABCG2 and p63. RESULTS The growth rates of the cultivated cells, or the times it took them to reach confluency, were different for the three scaffolds. The cultivated sheet on the temperature-responsive dish consisted of 2-3 layers, while those on the collagen gel and on the amniotic membrane consisted of 5-8 layers. The basal layer cells grown on all three scaffolds expressed putative stem cell markers. In real-time RT-PCR analysis, the highest level of p63 was observed in the sheets grown on collagen gel. CONCLUSIONS In this study, the cells cultured on the collagen gel demonstrated a capacity for cell proliferation, and the expressions of stem cells in the sheets suggested that collagen gel is the most suitable carrier for clinical use.
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Affiliation(s)
- Eunryel Nam
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoki Fujita
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Maresuke Morita
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Keiko Tsuzuki
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hsing Yi Lin
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Cheng Shu Chung
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takayuki Nakagawa
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryohei Nishimura
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Zhang W, Yang W, Liu X, Zhang L, Huang W, Zhang Y. Rapidly constructed scaffold-free embryonic stem cell sheets for ocular surface reconstruction. SCANNING 2014; 36:286-92. [PMID: 23861021 DOI: 10.1002/sca.21103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 04/25/2013] [Accepted: 05/09/2013] [Indexed: 05/13/2023]
Abstract
This study is an extension of our previously published work demonstrating the generation of corneal epithelial sheets using optimal centrifugation procedure. In this study, we investigated the therapeutic potential of embryonic stem cells (ESCs) for ocular surface reconstruction in rabbits with limbal stem cell deficiency (LSCD) using the centrifugation method. Rabbits with LSCD were assigned to two groups: 30 LSCD rabbits were treated with scaffold-free embryonic stem cells sheets (SESCS) and six LSCD rabbits received no treatment (control group). The two groups were followed up for 15 days using slit lamp observation. Cytokeratin K3, mucin 5AC, and OCT-4 were used to evaluate the re-epithelialization of the cornea. Fluorescent DiIC18(3)-DS dye was used to trace the transplanted cells. Atomic force microscopy (AFM) was used to investigate the cultured epithelial cells of the SESCS-treated group. The SESCS transplant facilitated the reconstruction of the ocular surface in 75% of the treated animals. Conjunctivalization and neovascularization were observed in the control group. The SESCS group was K3 positive and MUC5AC negative, and OCT-4 was observed on the re-epithelialized corneal epithelium. Labeled SESCS cells were detected in vivo at 15 days post-transplant. Using AFM, three different types of cultured cells were identified in the rabbit corneal epithelium of the SESCS treatment group. The SESCS were demonstrated to reconstruct the ocular surface in rabbits with LSCD. ES cells differentiated into corneal epithelial cells when in direct contact with the stroma and thus can serve as a cell source in corneal tissue engineering.
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Affiliation(s)
- Wei Zhang
- Department of Ophthalmology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, P.R. China
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Reconstruction of auto-tissue-engineered lamellar cornea by dynamic culture for transplantation: a rabbit model. PLoS One 2014; 9:e93012. [PMID: 24705327 PMCID: PMC3976280 DOI: 10.1371/journal.pone.0093012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 02/27/2014] [Indexed: 12/13/2022] Open
Abstract
To construct an auto-tissue-engineered lamellar cornea (ATELC) for transplantation, based on acellular porcine corneal stroma and autologous corneal limbal explants, a dynamic culture process, which composed of a submersion culture, a perfusion culture and a dynamic air-liquid interface culture, was performed using appropriate parameters. The results showed that the ATELC-Dynamic possessed histological structure and DNA content that were similar to native lamellar cornea (NLC, p>0.05). Compared to NLC, the protein contents of zonula occludens-1, desmocollin-2 and integrin β4 in ATELC-Dynamic reached 93%, 89% and 73%, respectively. The basal cells of ATELC-Dynamic showed a better differentiation phenotype (K3−, P63+, ABCG2+) compared with that of ATELC in static air-lift culture (ATELC-Static, K3+, P63−, ABCG2−). Accordingly, the cell-cloning efficiency of ATELC-Dynamic (9.72±3.5%) was significantly higher than that of ATELC-Static (2.13±1.46%, p<0.05). The levels of trans-epithelial electrical resistance, light transmittance and areal modulus variation in ATELC-Dynamic all reached those of NLC (p>0.05). Rabbit lamellar keratoplasty showed that the barrier function of ATELC-Dynamic was intact, and there were no signs of epithelial shedding or neovascularization. Furthermore, the ATELC-Dynamic group had similar optical properties and wound healing processes compared with the NLC group. Thus, the sequential dynamic culture process that was designed according to corneal physiological characteristics could successfully reconstruct an auto-lamellar cornea with favorable morphological characteristics and satisfactory physiological function.
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Hassanzadeh P, Kharaziha M, Nikkhah M, Shin SR, Jin J, He S, Sun W, Zhong C, Dokmeci MR, Khademhosseini A, Rolandi M. Chitin Nanofiber Micropatterned Flexible Substrates for Tissue Engineering †. J Mater Chem B 2013; 1:10.1039/C3TB20782J. [PMID: 24179675 PMCID: PMC3809896 DOI: 10.1039/c3tb20782j] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Engineered tissues require enhanced organization of cells and extracellular matrix (ECM) for proper function. To promote cell organization, substrates with controlled micro- and nanopatterns have been developed as supports for cell growth, and to induce cellular elongation and orientation via contact guidance. Micropatterned ultra-thin biodegradable substrates are desirable for implantation in the host tissue. These substrates, however, need to be mechanically robust to provide substantial support for the generation of new tissues, to be easily retrievable, and to maintain proper handling characteristics. Here, we introduce ultra-thin (<10 μm), self-assembled chitin nanofiber substrates micropatterned with replica molding for engineering cell sheets. These substrates are biodegradable, mechanically strong, yet flexible, and easily manipulated into the desired shape. As a proof-of-concept, fibroblast cell proliferation, elongation, and alignment were studied on the developed substrates with different pattern dimensions. On the optimized substrates, the majority of the cells aligned (<10°) along the major axis of micropatterned features. With the ease of fabrication and mechanical robustness, the substrates presented herein can be utilized as versatile system for the engineering and delivery of ordered tissue in applications such as myocardial repair.
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Affiliation(s)
- Pegah Hassanzadeh
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
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Wolchok JC, Tresco PA. Using growth factor conditioning to modify the properties of human cell derived extracellular matrix. Biotechnol Prog 2012; 28:1581-7. [PMID: 22915543 DOI: 10.1002/btpr.1625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 08/09/2012] [Indexed: 11/07/2022]
Abstract
We have recently reported on a bench-top approach for isolating extracellular matrix (ECM) from pure populations of cells grown in culture using sacrificial, open-celled foams to concentrate and capture the ECM. To increase both the accumulation and the strength of the ECM harvested, cell-seeded polyurethane (PU) foams were cultured in media supplemented with either transforming growth factor β-1 (TGFβ1) or hepatocyte growth factor (HGF). At the end of a 3-week culture period, ECM yield was significantly increased for samples conditioned in supplemented media. Control foams yielded 48 ± 12 mg of material for every gram of PU foam seeded. Yield values increased to 102 ± 21 and 243 ± 25 mg for HGF and TGFβ1-treated samples, respectively. HGF supplementation increased the modulus by 59%, while TGFβ1 treatment increased the elastic modulus by 204%. TGFβ1-stimulated material was organized into a network that was markedly denser than control material, with HGF-stimulated network density intermediate to TGFβ1 and controls. Our study showed that TGFβ1-treated samples were collagen enriched while HGF samples had an increased gylcosaminoglycan concentration. The results demonstrate that growth factor supplementation, particularly with TGFβ1, can significantly alter the biomechanical properties of cell-derived ECM that may be used for therapeutic applications.
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Affiliation(s)
- Jeffrey C Wolchok
- Dept. of Biomedical Engineering, College of Engineering, University of Arkansas, Fayetteville, AR, USA.
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Liu Z, Zhou Q, Zhu J, Xiao J, Wan P, Zhou C, Huang Z, Qiang N, Zhang W, Wu Z, Quan D, Wang Z. Using genipin-crosslinked acellular porcine corneal stroma for cosmetic corneal lens implants. Biomaterials 2012; 33:7336-46. [PMID: 22795849 DOI: 10.1016/j.biomaterials.2012.06.080] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 06/26/2012] [Indexed: 12/13/2022]
Abstract
Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at -10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m(2)/g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo. Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months.
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Affiliation(s)
- Zhao Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, PR China
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Zhang W, Xiao J, Li C, Wan P, Liu Y, Wu Z, Huang M, Wang X, Wang Z. Rapidly constructed scaffold-free cornea epithelial sheets for ocular surface reconstruction. Tissue Eng Part C Methods 2011; 17:569-77. [PMID: 21214400 DOI: 10.1089/ten.tec.2010.0529] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To develop a centrifugal cell seeding method for rapid and efficient reconstruction of ocular surface with limbal stem cell deficiency (LSCD) in rabbits. METHODS The orthogonal design method was used to optimize centrifugation parameters for cell seeding. Methylthiazol tetrazolium proliferation assay, colony-forming efficiency, and flow cytometry were used to study cell viability. Histology, electron microscopy, and immunocytochemistry were evaluated for centrifugation-constructed cornea epithelial sheets (CCCESs). The rabbit eyes with LSCD were treated with or without CCCES for in vivo evaluation. RESULTS The 80.04% attached cells with 98.04% viability were achieved using optimal cell seeding density at 9 × 10(5) cm(-2) with centrifugation at 1800 rpm for 4 min. The 0.4% glycerin was added in the medium to increase the surface tension and osmotic pressure to optimal condition for obtaining higher cell density. The three-layer epithelial sheets were rapid constructed, which displayed the characteristics of normal corneal epithelium. In vivo transplantation, labeled cells of CCCES were detected at 30 days. CCCES reconstructed the LSCD corneal epithelia without conjunctivalization and neovascularation, evidenced by positive K3 and negative K4, Muc5AC. CONCLUSION The scaffold-free corneal epithelial sheets were rapidly constructed using optimal centrifugation procedure, which was demonstrated to reconstruct ocular surface with LSCD.
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Affiliation(s)
- Wei Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, PR China
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