scholarly journals Isolation and Propagation of Human Corneal Stromal Keratocytes for Tissue Engineering and Cell Therapy

Cells ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 178
Author(s):  
Nur Zahirah binte M. Yusoff ◽  
Andri K. Riau ◽  
Gary H. F. Yam ◽  
Nuur Shahinda Humaira binte Halim ◽  
Jodhbir S. Mehta
Keyword(s):  
Tissue Engineering ◽  
Cell Therapy ◽  
Structural Integrity ◽  
Corneal Transplantation ◽  
Limiting Factor ◽  
Genotypic Differences ◽  
Corneal Tissue ◽  
Stromal Fibroblasts ◽  
Corneal Opacification

The human corneal stroma contains corneal stromal keratocytes (CSKs) that synthesize and deposit collagens and keratan sulfate proteoglycans into the stromal matrix to maintain the corneal structural integrity and transparency. In adult corneas, CSKs are quiescent and arrested in the G0 phase of the cell cycle. Following injury, some CSKs undergo apoptosis, whereas the surviving cells are activated to become stromal fibroblasts (SFs) and myofibroblasts (MyoFBs), as a natural mechanism of wound healing. The SFs and MyoFBs secrete abnormal extracellular matrix proteins, leading to corneal fibrosis and scar formation (corneal opacification). The issue is compounded by the fact that CSK transformation into SFs or MyoFBs is irreversible in vivo, which leads to chronic opacification. In this scenario, corneal transplantation is the only recourse. The application of cell therapy by replenishing CSKs, propagated in vitro, in the injured corneas has been demonstrated to be efficacious in resolving early-onset corneal opacification. However, expanding CSKs is challenging and has been the limiting factor for the application in corneal tissue engineering and cell therapy. The supplementation of serum in the culture medium promotes cell division but inevitably converts the CSKs into SFs. Similar to the in vivo conditions, the transformation is irreversible, even when the SF culture is switched to a serum-free medium. In the current article, we present a detailed protocol on the isolation and propagation of bona fide human CSKs and the morphological and genotypic differences from SFs.

scholarly journals Prospects and Challenges of Translational Corneal Bioprinting

2020 ◽  
Vol 7 (3) ◽  
pp. 71 ◽  
Author(s):  
Matthias Fuest ◽  
Gary Hin-Fai Yam ◽  
Jodhbir S. Mehta ◽  
Daniela F. Duarte Campos
Keyword(s):  
Tissue Engineering ◽  
Ex Vivo ◽  
Corneal Transplantation ◽  
Human Cornea ◽  
Corneal Tissue ◽  
Full Thickness ◽  
Future Directions ◽  
Spatial Control

Corneal transplantation remains the ultimate treatment option for advanced stromal and endothelial disorders. Corneal tissue engineering has gained increasing interest in recent years, as it can bypass many complications of conventional corneal transplantation. The human cornea is an ideal organ for tissue engineering, as it is avascular and immune-privileged. Mimicking the complex mechanical properties, the surface curvature, and stromal cytoarchitecure of the in vivo corneal tissue remains a great challenge for tissue engineering approaches. For this reason, automated biofabrication strategies, such as bioprinting, may offer additional spatial control during the manufacturing process to generate full-thickness cell-laden 3D corneal constructs. In this review, we discuss recent advances in bioprinting and biomaterials used for in vitro and ex vivo corneal tissue engineering, corneal cell-biomaterial interactions after bioprinting, and future directions of corneal bioprinting aiming at engineering a full-thickness human cornea in the lab.

Collagen/silica nanocomposites and hybrids for bone tissue engineering

2013 ◽  
Vol 2 (4) ◽  
pp. 427-447 ◽  
Author(s):  
Bapi Sarker ◽  
Stefan Lyer ◽  
Andreas Arkudas ◽  
Aldo R. Boccaccini
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Self Assembly ◽  
Structural Integrity ◽  
Organic Matrix ◽  
Angiogenic Potential ◽  
Silica Nanocomposites

AbstractCollagen is increasingly attracting attention for bone tissue engineering applications. However, due to its low mechanical properties, applications including mechanical loads or requiring structural integrity are limited. To tackle this handicap, collagen can be combined with (nanoscale) silica in a variety of composite materials that are attractive for bone tissue engineering. Considering research carried out in the past 15 years, this article reviews the literature discussing the development of silica/collagen composites that have been synthesized by adding silica from different sources as inorganic bioactive material to collagen as organic matrix. Different routes for the fabrication of collagen/silica composites are presented, focusing on nanocomposites. In vitro cell bioactivity studies demonstrated the osteogenic and, in some cases, angiogenic potential of the composites. Relevant in vivo studies discussing integration of the materials in bone tissue are discussed. Due to the understanding of possible interaction between silicon species and collagen, the effect of different silica precursors on the collagen self-assembly process is also discussed. On the basis of literature results and as discussed in this review, collagen/silica nanocomposites and hybrids represent attractive biomaterials for bone regeneration applications.

scholarly journals Biomaterials for corneal endothelial cell culture and tissue engineering

2021 ◽  
Vol 12 ◽  
pp. 204173142199053
Author(s):  
Mohit Parekh ◽  
Vito Romano ◽  
Kareem Hassanin ◽  
Valeria Testa ◽  
Rintra Wongvisavavit ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Standard Treatment ◽  
Corneal Endothelial Cell ◽  
Corneal Tissue ◽  
Corneal Endothelial Cells ◽  
Endothelial Cell Culture ◽  
Corneal Transplants

The corneal endothelium is the posterior monolayer of cells that are responsible for maintaining overall transparency of the avascular corneal tissue via pump function. These cells are non-regenerative in vivo and therefore, approximately 40% of corneal transplants undertaken worldwide are a result of damage or dysfunction of endothelial cells. The number of available corneal donor tissues is limited worldwide, hence, cultivation of human corneal endothelial cells (hCECs) in vitro has been attempted in order to produce tissue engineered corneal endothelial grafts. Researchers have attempted to recreate the current gold standard treatment of replacing the endothelial layer with accompanying Descemet’s membrane or a small portion of stroma as support with tissue engineering strategies using various substrates of both biologically derived and synthetic origin. Here we review the potential biomaterials that are currently in development to support the transplantation of a cultured monolayer of hCECs.

scholarly journals Ectopic transient overexpression of OCT-4 facilitates BMP4-induced osteogenic transdifferentiation of human umbilical vein endothelial cells

2020 ◽  
Vol 11 ◽  
pp. 204173142090920
Author(s):  
Seung Hyun L Kim ◽  
Seunghun S Lee ◽  
Inseon Kim ◽  
Janet Kwon ◽  
Song Kwon ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Cell Therapy ◽  
Bone Morphogenetic Protein ◽  
Umbilical Vein ◽  
Cell Types ◽  
Bone Morphogenetic Protein 4 ◽  
Morphogenetic Protein ◽  
Umbilical Vein Endothelial Cells

Limitation in cell sources for autologous cell therapy has been a recent focus in stem cell therapy and tissue engineering. Among various research advances, direct conversion, or transdifferentiation, is a notable and feasible strategy for the generation and acquirement of wanted cell source. So far, utilizing cell transdifferentiation technology in tissue engineering was mainly restricted at achieving single wanted cell type from diverse cell types with high efficiency. However, regeneration of a complete tissue always requires multiple cell types which poses an intrinsic complexity. In this study, enhanced osteogenic differentiation was achieved by transient ectopic expression of octamer-binding transcription factor 4 ( OCT-4) gene followed by bone morphogenetic protein 4 treatment on human umbilical vein endothelial cells. OCT-4 transfection and bone morphogenetic protein 4 treatment resulted in enhanced expression of osteogenic markers such as core-binding factor alpha 1, alkaline phosphatase, and collagen 1 compared with bone morphogenetic protein 4 treatment alone. Furthermore, we employed gelatin-heparin cryogel in cranial defect model for in vivo bone formation. Micro-computed tomography and histological analysis of in vivo samples showed that OCT-4 transfection followed by bone morphogenetic protein 4 treatment resulted in efficient transdifferentiation of endothelial cells to osteogenic cells. These results suggest that the combination of OCT-4 and bone morphogenetic protein 4 on endothelial cells would be a reliable multicellular transdifferentiation model which could be applied for bone tissue engineering.

scholarly journals Use of Post-transplant Cyclophosphamide Treatment to Build a Tolerance Platform to Prevent Liquid and Solid Organ Allograft Rejection

2021 ◽  
Vol 12 ◽  
Author(s):  
Casey O. Lightbourn ◽  
Dietlinde Wolf ◽  
Sabrina N. Copsel ◽  
Ying Wang ◽  
Brent J. Pfeiffer ◽  
...  
Keyword(s):  
Corneal Transplantation ◽  
Organ Transplant ◽  
Tolerance Induction ◽  
Solid Organ ◽  
Corneal Tissue ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Cyclophosphamide Treatment ◽  
Immunological Rejection

Corneal transplantation (CT) is the most frequent type of solid organ transplant (SOT) performed worldwide. Unfortunately, immunological rejection is the primary cause of graft failure for CT and therefore advances in immune regulation to induce tolerance remains an unmet medical need. Recently, our work and others in pre-clinical studies found that cyclophosphamide (Cy) administered after (“post-transplant,” PTCy) hematopoietic stem cell transplantation (HSCT), i.e., liquid transplants is effective for graft vs. host disease prophylaxis and enhances overall survival. Importantly, within the past 10 years, PTCy has been widely adopted for clinical HSCT and the results at many centers have been extremely encouraging. The present studies found that Cy can be effectively employed to prolong the survival of SOT, specifically mouse corneal allografts. The results demonstrated that the timing of PTCy administration is critical for these CT and distinct from the kinetics employed following allogeneic HSCT. PTCy was observed to interfere with neovascularization, a process critically associated with immune rejection of corneal tissue that ensues following the loss of ocular “immune privilege.” PTCy has the potential to delete or directly suppress allo-reactive T cells and treatment here was shown to diminish T cell rejection responses. These PTCy doses were observed to spare significant levels of CD4+ FoxP3+ (Tregs) which were found to be functional and could readily receive stimulating signals leading to their in vivo expansion via TNFRSF25 and CD25 agonists. In total, we posit future studies can take advantage of Cy based platforms to generate combinatorial strategies for long-term tolerance induction.

Corneal epithelium tissue engineering: recent advances in regeneration and replacement of corneal surface

2020 ◽  
Author(s):  
Hamed Nosrati ◽  
Zahra Abpeikar ◽  
Zahra Gholami Mahmoudian ◽  
Mahdi Zafari ◽  
Jafar Majidi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Corneal Transplantation ◽  
Cell Types ◽  
Biological Properties ◽  
Corneal Tissue ◽  
Corneal Surface ◽  
Infection Transmission ◽  
Tissue Microenvironment ◽  
Corneal Regeneration ◽  
Different Cell Types

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe tissue-engineering and cell-based approaches for corneal regeneration.

CORNEAL TRANSPLANTATION AND THE ARTIFICIAL CORNEA

2003 ◽  
Vol 03 (01) ◽  
pp. 95-106 ◽  
Author(s):  
JULIE ALBON
Keyword(s):  
Corneal Transplantation ◽  
Basic Research ◽  
Corneal Transplant ◽  
Corneal Tissue ◽  
Artificial Cornea ◽  
Surface Protection ◽  
In Vitro Techniques ◽  
Wide Range

The clinical need for an alternative to donor corneal tissue has encouraged much interest in recent years. An artificial cornea whether it be bio-engineered or a synthetic keratoprosthesis must fulfill the functions of the cornea it replaces: transparent, refractive surface, protection, non-immunogenic. A wide range of implants and biomedical devices have been developed in an attempt to correct corneal blindness. Limitation of existing biomaterials are evident when reviewing keratoprosthesis surgery complications. These include infection, intraocular inflammation, retromembrane formation, inadequate interface seal thus epithelial downgrowth and glaucoma. Attempts to improve healing in such cases have involved using various polymers or tissues to surround the optic. The successes and failures of synthetic prostheses that have been implanted in humans is discussed. More recently, the idea of a bio-engineered cornea has arisen. Tissue-engineering involves the manipulation of cells using in vitro techniques to create a composite tissue, which could then be implanted in vivo. Corneal equivalents have been reconstructed from corneal cell lines. They already have their potential uses in the biomedical world: as replacements for animals in toxicology testing and pharmacological studies, as well as in basic research into cell-cell and cell-matrix interactions of corneal wound healing. Current research is ongoing to determine if the bio-engineered cornea will have a role in corneal transplant surgery.

scholarly journals Preliminary studies of constructing a tissue-engineered lamellar corneal graft by culturing mesenchymal stem cells onto decellularized corneal matrix

2021 ◽  
Vol 14 (1) ◽  
pp. 10-18
Author(s):  
Yu-Jie Cen ◽  
◽  
Wei Wang ◽  
Yun Feng ◽  
◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Corneal Transplantation ◽  
Corneal Graft ◽  
Lamellar Keratoplasty ◽  
Corneal Tissue ◽  
Isolated Cells ◽  
Post Transplantation ◽  
Donor Shortage

AIM: To construct a competent corneal lamellar substitute in order to alleviate the shortage of human corneal donor. METHODS: Rabbit mesenchymal stem cells (MSCs) were isolated from bone marrow and identified by flow cytometric, osteogenic and adipogenic induction. Xenogenic decellularized corneal matrix (XDCM) was generated from dog corneas. MSCs were seeded and cultured on XDCM to construct the tissue-engineered cornea. Post-transplantation biocompatibility of engineered corneal graft were tested by animal experiment. Rabbits were divided into two groups then underwent lamellar keratoplasty (LK) with different corneal grafts: 1) XDCM group (n=5): XDCM; 2) XDCM-MSCs groups (n=4): tissue-engineered cornea made up with XDCM and MSCs. The ocular surface recovery procedure was observed while corneal transparency, neovascularization and epithelium defection were measured and compared. In vivo on focal exam was performed 3mo postoperatively. RESULTS: Rabbit MSCs were isolated and identified. Flow cytometry demonstrated isolated cells were CD90 positive and CD34, CD45 negative. Osteogenic and adipogenic induction verified their multipotent abilities. MSC-XDCM grafts were constructed and observed. In vivo transplantation showed the neovascularization in XDCM-MSC group was much less than that in XDCM group postoperatively. Post-transplant 3-month confocal test showed less nerve regeneration and bigger cell-absent area in XDCM-MSC group. CONCLUSION: This study present a novel corneal tissue-engineered graft that could reduce post-operatively neovascularization and remain transparency, meanwhile shows that co-transplantation of MSCs may help increase corneal transplantation successful rate and enlarge the source range of corneal substitute to overcome cornea donor shortage.

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