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Hamilton NJI, Tait A, Weil B, Daniels J. The Use of a Dehydrated Cellularized Collagen Matrix to Replace Fibrotic Vocal Fold Mucosa. Laryngoscope 2024; 134:882-893. [PMID: 37681762 DOI: 10.1002/lary.31034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 09/09/2023]
Abstract
OBJECTIVES Fibrosis of the vocal fold lamina propria reduces vocal cord vibration resulting in a chronically hoarse voice. We describe a novel approach using umbilical cord-derived mesenchymal stem cells in a dehydrated collagen matrix (cellogen) to reconstruct the delicate balance of extracellular matrix within the vocal fold lamina propria whilst limiting the host inflammatory response to the implant. METHODS Human umbilical cord-derived mesenchymal stem-cells were embedded in bovine type I collagen hydrogel and dehydrated using the RAFT™ 3D culture system. The extracellular matrix, cellular viability and composition, paracrine profile, and genomic profile were assessed and the scaffold engrafted onto the hind muscle of NUDE mice. RESULTS The cells retained stem-cell markers following fabrication and secreted collagen III, fibronectin, and glycosaminoglycans within the scaffold. Electron microscopy showed the scaffold consisted of single strands of protein with interspersed bundles of a similar size to native vocal fold lamina propria. The use of the dehydration step improved cell viability and upregulated the expression of genes important in wound healing and matrix organization compared with unmodified collagen hydrogel carriers. The cells were shown to secrete exosomes and cytokines and, following engraftment within an immunocompromised mouse model, appeared to modulate the host inflammatory response compared with controls. CONCLUSION This article provides a scalable cell-protein scaffold that with further modifications could provide a replacement for lost or damaged vocal fold mucosa. Further investigations are required to assess the mechanical properties of the scaffold and inhibit the differentiation of the umbilical cord-derived stem-cells following implantation. Laryngoscope, 134:882-893, 2024.
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Affiliation(s)
- Nick J I Hamilton
- Head & Neck Academic Centre, UCL Division of Surgery and Interventional Sciences, University College London, London, UK
- Royal National Ear Nose & Throat Hospital, University College London Hospitals NHS Trust, London, UK
| | - Angela Tait
- Centre for Cell, Gene & Tissue Therapy, Royal Free London NHS Foundation Trust, London, UK
| | - Ben Weil
- Centre for Cell, Gene & Tissue Therapy, Royal Free London NHS Foundation Trust, London, UK
| | - Julie Daniels
- Cells for Sight, Institute of Ophthalmology, University College London, London, UK
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2
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Corneal Epithelial Regeneration: Old and New Perspectives. Int J Mol Sci 2022; 23:ijms232113114. [DOI: 10.3390/ijms232113114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/17/2022] Open
Abstract
Corneal blindness is the fifth leading cause of blindness worldwide, and therapeutic options are still often limited to corneal transplantation. The corneal epithelium has a strong barrier function, and regeneration is highly dependent on limbal stem cell proliferation and basement membrane remodeling. As a result of the lack of corneal donor tissues, regenerative medicine for corneal diseases affecting the epithelium is an area with quite advanced basic and clinical research. Surgery still plays a prominent role in the treatment of epithelial diseases; indeed, innovative surgical techniques have been developed to transplant corneal and non-corneal stem cells onto diseased corneas for epithelial regeneration applications. The main goal of applying regenerative medicine to clinical practice is to restore function by providing viable cells based on the use of a novel therapeutic approach to generate biological substitutes and improve tissue functions. Interest in corneal epithelium rehabilitation medicine is rapidly growing, given the exposure of the corneal outer layers to external insults. Here, we performed a review of basic, clinical and surgical research reports on regenerative medicine for corneal epithelial disorders, classifying therapeutic approaches according to their macro- or microscopic target, i.e., into cellular or subcellular therapies, respectively.
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3
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Hidalgo-Alvarez V, Dhowre HS, Kingston OA, Sheridan CM, Levis HJ. Biofabrication of Artificial Stem Cell Niches in the Anterior Ocular Segment. Bioengineering (Basel) 2021; 8:135. [PMID: 34677208 PMCID: PMC8533470 DOI: 10.3390/bioengineering8100135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The anterior segment of the eye is a complex set of structures that collectively act to maintain the integrity of the globe and direct light towards the posteriorly located retina. The eye is exposed to numerous physical and environmental insults such as infection, UV radiation, physical or chemical injuries. Loss of transparency to the cornea or lens (cataract) and dysfunctional regulation of intra ocular pressure (glaucoma) are leading causes of worldwide blindness. Whilst traditional therapeutic approaches can improve vision, their effect often fails to control the multiple pathological events that lead to long-term vision loss. Regenerative medicine approaches in the eye have already had success with ocular stem cell therapy and ex vivo production of cornea and conjunctival tissue for transplant recovering patients' vision. However, advancements are required to increase the efficacy of these as well as develop other ocular cell therapies. One of the most important challenges that determines the success of regenerative approaches is the preservation of the stem cell properties during expansion culture in vitro. To achieve this, the environment must provide the physical, chemical and biological factors that ensure the maintenance of their undifferentiated state, as well as their proliferative capacity. This is likely to be accomplished by replicating the natural stem cell niche in vitro. Due to the complex nature of the cell microenvironment, the creation of such artificial niches requires the use of bioengineering techniques which can replicate the physico-chemical properties and the dynamic cell-extracellular matrix interactions that maintain the stem cell phenotype. This review discusses the progress made in the replication of stem cell niches from the anterior ocular segment by using bioengineering approaches and their therapeutic implications.
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Affiliation(s)
- Veronica Hidalgo-Alvarez
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Hala S. Dhowre
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Olivia A. Kingston
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Carl M. Sheridan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Hannah J. Levis
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
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4
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Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options. Cells 2021; 10:cells10092302. [PMID: 34571952 PMCID: PMC8465583 DOI: 10.3390/cells10092302] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022] Open
Abstract
In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.
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5
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Anton-Sales I, Koivusalo L, Skottman H, Laromaine A, Roig A. Limbal Stem Cells on Bacterial Nanocellulose Carriers for Ocular Surface Regeneration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2003937. [PMID: 33586332 DOI: 10.1002/smll.202003937] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Limbal stem cells (LSCs) are already used in cell-based treatments for ocular surface disorders. Clinical translation of LSCs-based therapies critically depends on the successful delivery, survival, and retention of these therapeutic cells to the desired region. Such a major bottleneck could be overcome by using an appropriate carrier to provide anchoring sites and structural support to LSC culture and transplantation. Bacterial nanocellulose (BNC) is an appealing, yet unexplored, candidate for this application because of its biocompatibility, animal-free origin and mechanical stability. Here, BNC as a vehicle for human embryonic stem cells-derived LSC (hESC-LSC) are investigated. To enhance cell-biomaterial interactions, a plasma activation followed by a Collagen IV and Laminin coating of the BNC substrates is implemented. This surface functionalization with human extracellular matrix proteins greatly improved the attachment and survival of hESC-LSC without compromising the flexible, robust and semi-transparent nature of the BNC. The surface characteristics of the BNC substrates are described and a preliminary ex vivo test in simulated transplantation scenarios is provided. Importantly, it is shown that hESC-LSC retain their self-renewal and stemness characteristics up to 21 days on BNC substrates. These results open the door for future research on hESC-LSC/BNC constructs to treat severe ocular surface pathologies.
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Affiliation(s)
- Irene Anton-Sales
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Spain
| | - Laura Koivusalo
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere, 33520, Finland
| | - Heli Skottman
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere, 33520, Finland
| | - Anna Laromaine
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Spain
| | - Anna Roig
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Spain
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García-Posadas L, Diebold Y. Three-Dimensional Human Cell Culture Models to Study the Pathophysiology of the Anterior Eye. Pharmaceutics 2020; 12:E1215. [PMID: 33333869 PMCID: PMC7765302 DOI: 10.3390/pharmaceutics12121215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 02/07/2023] Open
Abstract
In recent decades, the establishment of complex three-dimensional (3D) models of tissues has allowed researchers to perform high-quality studies and to not only advance knowledge of the physiology of these tissues but also mimic pathological conditions to test novel therapeutic strategies. The main advantage of 3D models is that they recapitulate the spatial architecture of tissues and thereby provide more physiologically relevant information. The eye is an extremely complex organ that comprises a large variety of highly heterogeneous tissues that are divided into two asymmetrical portions: the anterior and posterior segments. The anterior segment consists of the cornea, conjunctiva, iris, ciliary body, sclera, aqueous humor, and the lens. Different diseases in these tissues can have devastating effects. To study these pathologies and develop new treatments, the use of cell culture models is instrumental, and the better the model, the more relevant the results. Thus, the development of sophisticated 3D models of ocular tissues is a significant challenge with enormous potential. In this review, we present a comprehensive overview of the latest advances in the development of 3D in vitro models of the anterior segment of the eye, with a special focus on those that use human primary cells.
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Affiliation(s)
- Laura García-Posadas
- Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
| | - Yolanda Diebold
- Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
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7
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McKay TB, Hutcheon AEK, Guo X, Zieske JD, Karamichos D. Modeling the cornea in 3-dimensions: Current and future perspectives. Exp Eye Res 2020; 197:108127. [PMID: 32619578 PMCID: PMC8116933 DOI: 10.1016/j.exer.2020.108127] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 02/08/2023]
Abstract
The cornea is an avascular, transparent ocular tissue that serves as a refractive and protective structure for the eye. Over 90% of the cornea is composed of a collagenous-rich extracellular matrix within the stroma with the other 10% composed by the corneal epithelium and endothelium layers and their corresponding supporting collagen layers (e.g., Bowman's and Descemet's membranes) at the anterior and posterior cornea, respectively. Due to its prominent role in corneal structure, tissue engineering approaches to model the human cornea in vitro have focused heavily on the cellular and functional properties of the corneal stroma. In this review, we discuss model development in the context of culture dimensionality (e.g., 2-dimensional versus 3-dimensional) and expand on the optical, biomechanical, and cellular functions promoted by the culture microenvironment. We describe current methods to model the human cornea with focus on organotypic approaches, compressed collagen, bioprinting, and self-assembled stromal models. We also expand on co-culture applications with the inclusion of relevant corneal cell types, such as epithelial, stromal keratocyte or fibroblast, endothelial, and neuronal cells. Further advancements in corneal tissue model development will markedly improve our current understanding of corneal wound healing and regeneration.
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Affiliation(s)
- Tina B McKay
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Audrey E K Hutcheon
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Xiaoqing Guo
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - James D Zieske
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
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8
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Cabral JV, Jackson CJ, Utheim TP, Jirsova K. Ex vivo cultivated oral mucosal epithelial cell transplantation for limbal stem cell deficiency: a review. Stem Cell Res Ther 2020; 11:301. [PMID: 32693830 PMCID: PMC7374839 DOI: 10.1186/s13287-020-01783-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/26/2020] [Accepted: 06/18/2020] [Indexed: 01/19/2023] Open
Abstract
Destruction or dysfunction of limbal epithelial stem cells (LESCs) leads to unilateral or bilateral limbal stem cell deficiency (LSCD). Fifteen years have passed since the first transplantation of ex vivo cultivated oral mucosal epithelial cells (COMET) in humans in 2004, which represents the first use of a cultured non-limbal autologous cell type to treat bilateral LSCD. This review summarizes clinical outcomes from COMET studies published from 2004 to 2019 and reviews results with emphasis on the culture methods by which grafted cell sheets were prepared.
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Affiliation(s)
- Joao Victor Cabral
- Laboratory of the Biology and Pathology of the Eye, Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Catherine Joan Jackson
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.,Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.,Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
| | - Tor Paaske Utheim
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.,Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway.,Department of Ophthalmology, Sørlandet Hospital Trust Arendal, Arendal, Norway
| | - Katerina Jirsova
- Laboratory of the Biology and Pathology of the Eye, Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
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9
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Hong H, Kim H, Han SJ, Jang J, Kim HK, Cho DW, Kim DS. Compressed collagen intermixed with cornea-derived decellularized extracellular matrix providing mechanical and biochemical niches for corneal stroma analogue. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 103:109837. [DOI: 10.1016/j.msec.2019.109837] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/18/2019] [Accepted: 05/29/2019] [Indexed: 01/07/2023]
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10
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McKay TB, Seyed-Razavi Y, Ghezzi CE, Dieckmann G, Nieland TJF, Cairns DM, Pollard RE, Hamrah P, Kaplan DL. Corneal pain and experimental model development. Prog Retin Eye Res 2019; 71:88-113. [PMID: 30453079 PMCID: PMC6690397 DOI: 10.1016/j.preteyeres.2018.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/03/2018] [Accepted: 11/13/2018] [Indexed: 12/13/2022]
Abstract
The cornea is a valuable tissue for studying peripheral sensory nerve structure and regeneration due to its avascularity, transparency, and dense innervation. Somatosensory innervation of the cornea serves to identify changes in environmental stimuli at the ocular surface, thereby promoting barrier function to protect the eye against injury or infection. Due to regulatory demands to screen ocular safety of potential chemical exposure, a need remains to develop functional human tissue models to predict ocular damage and pain using in vitro-based systems to increase throughput and minimize animal use. In this review, we summarize the anatomical and functional roles of corneal innervation in propagation of sensory input, corneal neuropathies associated with pain, and the status of current in vivo and in vitro models. Emphasis is placed on tissue engineering approaches to study the human corneal pain response in vitro with integration of proper cell types, controlled microenvironment, and high-throughput readouts to predict pain induction. Further developments in this field will aid in defining molecular signatures to distinguish acute and chronic pain triggers based on the immune response and epithelial, stromal, and neuronal interactions that occur at the ocular surface that lead to functional outcomes in the brain depending on severity and persistence of the stimulus.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Yashar Seyed-Razavi
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Gabriela Dieckmann
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Thomas J F Nieland
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Rachel E Pollard
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA.
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11
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Mobaraki M, Abbasi R, Omidian Vandchali S, Ghaffari M, Moztarzadeh F, Mozafari M. Corneal Repair and Regeneration: Current Concepts and Future Directions. Front Bioeng Biotechnol 2019; 7:135. [PMID: 31245365 PMCID: PMC6579817 DOI: 10.3389/fbioe.2019.00135] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 05/20/2019] [Indexed: 12/13/2022] Open
Abstract
The cornea is a unique tissue and the most powerful focusing element of the eye, known as a window to the eye. Infectious or non-infectious diseases might cause severe visual impairments that need medical intervention to restore patients' vision. The most prominent characteristics of the cornea are its mechanical strength and transparency, which are indeed the most important criteria considerations when reconstructing the injured cornea. Corneal strength comes from about 200 collagen lamellae which criss-cross the cornea in different directions and comprise nearly 90% of the thickness of the cornea. Regarding corneal transparency, the specific characteristics of the cornea include its immune and angiogenic privilege besides its limbus zone. On the other hand, angiogenic privilege involves several active cascades in which anti-angiogenic factors are produced to compensate for the enhanced production of proangiogenic factors after wound healing. Limbus of the cornea forms a border between the corneal and conjunctival epithelium, and its limbal stem cells (LSCs) are essential in maintenance and repair of the adult cornea through its support of corneal epithelial tissue repair and regeneration. As a result, the main factors which threaten the corneal clarity are inflammatory reactions, neovascularization, and limbal deficiency. In fact, the influx of inflammatory cells causes scar formation and destruction of the limbus zone. Current studies about wound healing treatment focus on corneal characteristics such as the immune response, angiogenesis, and cell signaling. In this review, studied topics related to wound healing and new approaches in cornea regeneration, which are mostly related to the criteria mentioned above, will be discussed.
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Affiliation(s)
- Mohammadmahdi Mobaraki
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Reza Abbasi
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Sajjad Omidian Vandchali
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Maryam Ghaffari
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Fathollah Moztarzadeh
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Masoud Mozafari
- Department of Tissue Engineering and Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
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12
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In Vitro Cultivation of Limbal Epithelial Stem Cells on Surface-Modified Crosslinked Collagen Scaffolds. Stem Cells Int 2019; 2019:7867613. [PMID: 31065280 PMCID: PMC6466865 DOI: 10.1155/2019/7867613] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/31/2018] [Indexed: 12/13/2022] Open
Abstract
Purpose To investigate the efficacy of recombinant human collagen type I (RHC I) and collagen-like peptide (CLP) hydrogels as alternative carrier substrates for the cultivation of limbal epithelial stem cells (LESC) under xeno-free culture conditions. Methods Human LESC were cultivated on seven different collagen-derived hydrogels: (1) unmodified RHC I, (2) fibronectin-patterned RHC I, (3) carbodiimide-crosslinked CLP (CLP-12 EDC), (4) DMTMM- (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium-) crosslinked CLP (CLP-12), (5) fibronectin-patterned CLP-12, (6) “3D limbal niche-mimicking” CLP-12, and (7) DMTMM-crosslinked CLP made from higher CLP concentration solution. Cell proliferation, cell morphology, and expression of LESC markers were analyzed. All data were compared to cultures on human amniotic membrane (HAM). Results Human LESC were successfully cultivated on six out of seven hydrogel formulations, with primary cell cultures on CLP-12 EDC being deemed unsuccessful since the area of outgrowth did not meet quality standards (i.e., inconsistence in outgrowth and confluence) after 14 days of culture. Upon confluence, primary LESC showed high expression of the stem cell marker ΔNp63, proliferation marker cytokeratin (KRT) 14, adhesion markers integrin-β4 and E-cadherin, and LESC-specific extracellular matrix proteins laminin-α1, and collagen type IV. Cells showed low expression of differentiation markers KRT3 and desmoglein 3 (DSG3). Significantly higher gene expression of KRT3 was observed for cells cultured on CLP hydrogels compared to RHC I and HAM. Surface patterning of hydrogels influenced the pattern of proliferation but had no significant effect on the phenotype or genotype of cultures. Overall, the performance of RHC I and DMTMM-crosslinked CLP hydrogels was equivalent to that of HAM. Conclusion RHC I and DMTMM-crosslinked CLP hydrogels, irrespective of surface modification, support successful cultivation of primary human LESC using a xeno-free cultivation protocol. The regenerated epithelium maintained similar characteristics to HAM-based cultures.
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Palchesko RN, Carrasquilla SD, Feinberg AW. Natural Biomaterials for Corneal Tissue Engineering, Repair, and Regeneration. Adv Healthc Mater 2018; 7:e1701434. [PMID: 29845780 DOI: 10.1002/adhm.201701434] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 03/01/2018] [Indexed: 12/13/2022]
Abstract
Corneal blindness is a major cause of vision loss, estimated to affect over 10 million people worldwide. Once impaired through clouding or shape change, the best treatment option for restoring vision is corneal transplantation using full or partial thickness cadaveric grafts. However, donor corneas are globally limited and face rejection and graft failure, similar to other transplanted organs. Thus, there is a need for viable alternatives to donor corneas in order to increase supply, reduce rejection, and to minimize variability in tissue quality. To address this, researchers have developed new materials and strategies to tissue engineer full or partial thickness cornea grafts in order to repair, regenerate, or replace the diseased cornea. This progress report first reviews the anatomy and physiology of the cornea to frame the biological requirements and discuss the injuries and diseases that necessitate the need fortransplantation, as well as the requirements for a suitable donor tissue alternative. This is followed by recent progress using naturally derived biomaterials including silk, collagen, amniotic membranes, and decellularized corneas. Finally, remaining challenges in the field as they relate to the biomaterials discussed are identified, and the future research directions that should result in further advances in restoring corneal vision are highlighted.
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Affiliation(s)
- Rachelle N. Palchesko
- Department of Biomedical Engineering; Carnegie Mellon University; Pittsburgh PA 15213 USA
- Louis J. Fox Center for Vision Restoration; University of Pittsburgh and UPMC; Pittsburgh PA 15213 USA
| | | | - Adam W. Feinberg
- Department of Biomedical Engineering; Carnegie Mellon University; Pittsburgh PA 15213 USA
- Louis J. Fox Center for Vision Restoration; University of Pittsburgh and UPMC; Pittsburgh PA 15213 USA
- Department of Materials Science and Engineering; Carnegie Mellon University; Pittsburgh PA 15213 USA
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Hong H, Huh MI, Park SM, Lee KP, Kim HK, Kim DS. Decellularized corneal lenticule embedded compressed collagen: toward a suturable collagenous construct for limbal reconstruction. Biofabrication 2018; 10:045001. [PMID: 29978836 DOI: 10.1088/1758-5090/aad1a4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recently, compressed collagen has attracted much attention as a potential alternative for a limbal epithelial stem cell (LESC) carrier to treat limbal stem cell deficiency (LSCD), in that it can provide mechanically improved collagen fibrillar structures compared to conventional collagen hydrogel. However, its clinical efficacy as an LESC carrier has not yet been studied through in vivo transplantation due to limited mechanical strength that cannot withstand a force induced by surgical suturing and low resistance to enzymatic degradation. This study firstly presents a suturable LESC carrier based on compressed collagen in the form of a biocomposite. The biocomposite was achieved by integrating a decellularized corneal lenticule, which is a decellularized stromal tissue obtained from corneal refractive surgery, inside a compressed collagen to form a sandwich structure. A suture retention test verified that the biocomposite has a much higher suture retention strength (0.56 ± 0.12 N) compared to the compressed collagen (0.02 ± 0.01 N). The biocomposite also exhibited more than 3 times higher resistance to enzymatic degradation, indicating long-term stability after transplantation. In vitro cell culture results revealed that the biocomposite effectively supported the expansion and stratification of the LESCs with expressions of putative stem cell and differentiated corneal epithelial cell markers. Finally, the biocomposite verified its clinical efficacy by stably delivering the LESCs onto an eye of a rabbit model of LSCD and effectively reconstructing the ocular surface.
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Affiliation(s)
- Hyeonjun Hong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongbuk, 37673, Republic of Korea
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15
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Shojaati G, Khandaker I, Sylakowski K, Funderburgh ML, Du Y, Funderburgh JL. Compressed Collagen Enhances Stem Cell Therapy for Corneal Scarring. Stem Cells Transl Med 2018; 7:487-494. [PMID: 29654654 PMCID: PMC5980128 DOI: 10.1002/sctm.17-0258] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/17/2018] [Indexed: 12/13/2022] Open
Abstract
Stem cells from human corneal stroma (CSSC) suppress corneal stromal scarring in a mouse wound‐healing model and promote regeneration of native transparent tissue (PMID:25504883). This study investigated efficacy of compressed collagen gel (CCG) as a vehicle to deliver CSSC for corneal therapy. CSSC isolated from limbal stroma of human donor corneas were embedded in soluble rat‐tendon collagen, gelled at 37°C, and partially dehydrated to a thickness of 100 µm by passive absorption. The CCG disks were dimensionally stable, easy to handle, and could be adhered securely to de‐epithelialized mouse cornea with fibrin‐based adhesive. CSSC in CCG maintained >80% viability for >1 week in culture media and could be cryopreserved in 20% fetal bovine serum‐10%DMSO in liquid nitrogen. CCG containing as few as 500 CSSC effectively prevented visible scarring and suppressed expression of fibrotic Col3a1 mRNA. CSSC in CCG were more effective at blocking scarring on a per‐cell basis than CSSC delivered directly in a fibrin gel as previously described. Collagen‐embedded cells retained the ability to suppress corneal scarring after conventional cryopreservation. This study demonstrates use of a common biomaterial that can facilitate storage and handling of stem cells in a manner that may provide off‐the‐shelf delivery of stem cells as a therapy for corneal scarring. stemcellstranslationalmedicine2018;7:487–494
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Affiliation(s)
- Golnar Shojaati
- Department of Ophthalmology, Kantonsspital Winterthur, Zurich, Switzerland.,Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Irona Khandaker
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kyle Sylakowski
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Martha L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - James L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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16
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Prina E, Mistry P, Sidney LE, Yang J, Wildman RD, Bertolin M, Breda C, Ferrari B, Barbaro V, Hopkinson A, Dua HS, Ferrari S, Rose FRAJ. 3D Microfabricated Scaffolds and Microfluidic Devices for Ocular Surface Replacement: a Review. Stem Cell Rev Rep 2018; 13:430-441. [PMID: 28573367 DOI: 10.1007/s12015-017-9740-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In recent years, there has been increased research interest in generating corneal substitutes, either for use in the clinic or as in vitro corneal models. The advancement of 3D microfabrication technologies has allowed the reconstruction of the native microarchitecture that controls epithelial cell adhesion, migration and differentiation. In addition, such technology has allowed the inclusion of a dynamic fluid flow that better mimics the physiology of the native cornea. We review the latest innovative products in development in this field, from 3D microfabricated hydrogels to microfluidic devices.
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Affiliation(s)
- Elisabetta Prina
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Pritesh Mistry
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Laura E Sidney
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Jing Yang
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Ricky D Wildman
- Faculty of Engineering, University of Nottingham, Nottingham, UK
| | - Marina Bertolin
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Claudia Breda
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Barbara Ferrari
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Vanessa Barbaro
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Andrew Hopkinson
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Harminder S Dua
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Stefano Ferrari
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy.
| | - Felicity R A J Rose
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
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17
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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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18
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Belair DG, Abbott BD. Engineering epithelial-stromal interactions in vitro for toxicology assessment. Toxicology 2017; 382:93-107. [PMID: 28285100 DOI: 10.1016/j.tox.2017.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/06/2017] [Indexed: 12/17/2022]
Abstract
Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue homeostasis. Epithelial-stromal interactions (ESIs) have historically been examined using mammalian models and ex vivo tissue recombination. Although these approaches have elucidated signaling mechanisms underlying embryonic morphogenesis processes and adult mammalian epithelial tissue function, they are limited by the availability of tissue, low throughput, and human developmental or physiological relevance. In this review, we describe how bioengineered ESIs, using either human stem cells or co-cultures of human primary epithelial and stromal cells, have enabled the development of human in vitro epithelial tissue models that recapitulate the architecture, phenotype, and function of adult human epithelial tissues. We discuss how the strategies used to engineer mature epithelial tissue models in vitro could be extrapolated to instruct the design of organotypic culture models that can recapitulate the structure of embryonic ectodermal tissues and enable the in vitro assessment of events critical to organ/tissue morphogenesis. Given the importance of ESIs towards normal epithelial tissue development and function, such models present a unique opportunity for toxicological screening assays to incorporate ESIs to assess the impact of chemicals on mature and developing epidermal tissues.
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Affiliation(s)
- David G Belair
- US EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Developmental Toxicology Branch, Research Triangle Park, NC 27711, United States.
| | - Barbara D Abbott
- US EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Developmental Toxicology Branch, Research Triangle Park, NC 27711, United States
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19
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Quan Y, Zhang X, Xu S, Li K, Zhu F, Li Q, Cai X, Lu R. Tcf7l2 localization of putative stem/progenitor cells in mouse conjunctiva. Am J Physiol Cell Physiol 2016; 311:C246-54. [PMID: 27281479 DOI: 10.1152/ajpcell.00014.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/02/2016] [Indexed: 12/23/2022]
Abstract
Conjunctival integrity and preservation is indispensable for vision. The self-renewing capacity of conjunctival cells controls conjunctival homeostasis and regeneration; however, the source of conjunctival self-renewal and the underlying mechanism is currently unclear. Here, we characterize the biochemical phenotype and proliferative potential of conjunctival epithelial cells in adult mouse by detecting proliferation-related signatures and conducting clonal analysis. Further, we show that transcription factor 7-like 2 (T-cell-specific transcription factor 4), a DNA binding protein expressed in multiple types of adult stem cells, is highly correlated with proliferative signatures in basal conjunctival epithelia. Clonal studies demonstrated that Transcription factor 7-like 2 (Tcf7l2) was coexpressed with p63α and proliferating cell nuclear antigen (PCNA) in propagative colonies. Furthermore, Tcf7l2 was actively transcribed concurrently with conjunctival epithelial proliferation in vitro. Collectively, we suggest that Tcf7l2 may be involved in maintenance of stem/progenitor cells properties of conjunctival epithelial stem/progenitor cells, and with the fornix as the optimal site to isolate highly proliferative conjunctival epithelial cells in adult mice.
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Affiliation(s)
- Yadan Quan
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Xinchun Zhang
- Hospital of Stomatology, Guanghua College of Stomatology, Sun Yat-Sen University, Guangzhou, China
| | - Siying Xu
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Kang Li
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Feng Zhu
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Qian Li
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Xianxian Cai
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
| | - Rong Lu
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China; and
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20
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Human pluripotent stem cell-derived limbal epithelial stem cells on bioengineered matrices for corneal reconstruction. Exp Eye Res 2015; 146:26-34. [PMID: 26658714 DOI: 10.1016/j.exer.2015.11.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/23/2015] [Accepted: 11/25/2015] [Indexed: 12/13/2022]
Abstract
Corneal epithelium is renewed by limbal epithelial stem cells (LESCs), a type of tissue-specific stem cells located in the limbal palisades of Vogt at the corneo-scleral junction. Acute trauma or inflammatory disorders of the ocular surface can destroy these stem cells, leading to limbal stem cell deficiency (LSCD) - a painful and vision-threatening condition. Treating these disorders is often challenging and complex, especially in bilateral cases with extensive damage. Human pluripotent stem cells (hPSCs) provide new opportunities for corneal reconstruction using cell-based therapy. Here, we investigated the use of hPSC-derived LESC-like cells on bioengineered collagen matrices in serum-free conditions, aiming for clinical applications to reconstruct the corneal epithelium and partially replace the damaged stroma. Differentiation of hPSCs towards LESC-like cells was directed using small-molecule induction followed by maturation in corneal epithelium culture medium. After four to five weeks of culture, differentiated cells were seeded onto bioengineered matrices fabricated as transparent membranes of uniform thickness, using medical-grade porcine collagen type I and a hybrid cross-linking technology. The bioengineered matrices were fully transparent, with high water content and swelling capacity, and parallel lamellar microstructure. Cell proliferation of hPSC-LESCs was significantly higher on bioengineered matrices than on collagen-coated control wells after two weeks of culture, and LESC markers p63 and cytokeratin 15, along with proliferation marker Ki67 were expressed even after 30 days in culture. Overall, hPSC-LESCs retained their capacity to self-renew and proliferate, but were also able to terminally differentiate upon stimulation, as suggested by protein expression of cytokeratins 3 and 12. We propose the use of bioengineered collagen matrices as carriers for the clinically-relevant hPSC-derived LESC-like cells, as a novel tissue engineering approach for corneal reconstruction.
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21
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Massie I, Kureshi AK, Schrader S, Shortt AJ, Daniels JT. Optimization of optical and mechanical properties of real architecture for 3-dimensional tissue equivalents: Towards treatment of limbal epithelial stem cell deficiency. Acta Biomater 2015; 24:241-250. [PMID: 26092352 PMCID: PMC4550494 DOI: 10.1016/j.actbio.2015.06.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 06/05/2015] [Accepted: 06/09/2015] [Indexed: 12/13/2022]
Abstract
Limbal epithelial stem cell (LESC) deficiency can cause blindness. Transplantation of cultured human limbal epithelial cells (hLE) on human amniotic membrane (HAM) can restore vision but clinical graft manufacture can be unreliable. We have developed a reliable and robust tissue equivalent (TE) alternative to HAM, Real Architecture for 3D Tissue (RAFT). Here, we aimed to optimize the optical and mechanical properties of RAFT TE for treatment of LESC deficiency in clinical application. The RAFT TE protocol is tunable; varying collagen concentration and volume produces differing RAFT TEs. These were compared with HAM samples taken from locations proximal and distal to the placental disc. Outcomes assessed were transparency, thickness, light transmission, tensile strength, ease of handling, degradation rates and suitability as substrate for hLE culture. Proximal HAM samples were thicker and stronger with poorer optical properties than distal HAM samples. RAFT TEs produced using higher amounts of collagen were thicker and stronger with poorer optical properties than those produced using lower amounts of collagen. The ‘optimal’ RAFT TE was thin, transparent but still handleable and was produced using 0.6 ml of 3 mg/ml collagen. Degradation rates of the ‘optimal’ RAFT TE and HAM were similar. hLE achieved confluency on ‘optimal’ RAFT TEs at comparable rates to HAM and cells expressed high levels of putative stem cell marker p63α. These findings support the use of RAFT TE for hLE transplantation towards treatment of LESC deficiency.
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22
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Sati A, Shukla S, Lal I, Sangwan VS. Treating limbal stem cell deficiency: current and emerging therapies. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1035253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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23
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Tissue Engineering the Cornea: The Evolution of RAFT. J Funct Biomater 2015; 6:50-65. [PMID: 25809689 PMCID: PMC4384100 DOI: 10.3390/jfb6010050] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 01/13/2015] [Indexed: 12/13/2022] Open
Abstract
Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro.
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