Amniotic membrane immobilized poly(vinyl alcohol) hybrid polymer as an artificial cornea scaffold that supports a stratified and differentiated corneal epithelium

Abstract

Poly(vinyl alcohol) (PVA) is a biocompatible, transparent hydrogel with physical strength that makes it promising as a material for an artificial cornea. In our previous study, type I collagen was immobilized onto PVA (PVA‐COL) as a possible artificial cornea scaffold that can sustain a functional corneal epithelium. The cellular adhesiveness of PVA in vitro was improved by collagen immobilization; however, stable epithelialization was not achieved in vivo. To improve epithelialization in vivo, we created an amniotic membrane (AM)‐immobilized polyvinyl alcohol hydrogel (PVA‐AM) for use as an artificial cornea material. AM was attached to PVA‐COL using a tissue adhesive consisting of collagen and citric acid derivative (CAD) as a crosslinker. Rabbit corneal epithelial cells were air‐lift cultured with 3T3 feeder fibroblasts to form a stratified epithelial layer on PVA‐AM. The rabbit corneal epithelial cells formed 3–5 layers of keratin‐3‐positive epithelium on PVA‐AM. Occludin‐positive cells were observed lining the superficial epithelium, the gap‐junctional protein connexin43‐positive cells was localized to the cell membrane of the basal epithelium, while both collagen IV were observed in the basement membrane. Epithelialization over implanted PVA‐AM was complete within 2 weeks, with little inflammation or opacification of the hydrogel. Corneal epithelialization on PVA‐AM in rabbit corneas improved over PVA‐COL, suggesting the possibility of using PVA‐AM as a biocompatible hybrid material for keratoprosthesis. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006

The Development of a Tissue-Engineered Cornea: Biomaterials and Culture Methods

“…Surrounding the core is a microperforated poly(hydroxyethyl acrylate) hydrogel that is also modified with type I collagen. The resulting material is highly transparent (96%) with a refractive index of 1.35, which is slightly lower than that of the cornea, Uchino et al designed a poly(vinyl alcohol) hydrogel crosslinked to an amniotic membrane (AM) to form a scaffold to support epithelial cell proliferation while providing a functional barrier similar to the basement membrane in vivo (48). This hydrogel was found to support the differentiation of epithelial cells; however, when transplanted into rabbit stroma, some eyes developed epithelial defects that resulted in the disintegration of AM and inflammation.…”

Exploring cell compatibility of a fibronectin‐functionalized physically crosslinked poly(vinyl alcohol) hydrogel

“…Cell type–specific immunostaining was performed to establish cell adhesion; thus, the aim of this procedure was not to indicate cell phenotype. PVA crosslinked using various chemical approaches has previously been investigated as a hybrid synthetic tissue39 or as functionalized PVA–tissue hybrids 40–44. All these approaches show promising results.…”

Hydrogels for Tissue Engineering and Delivery of Tissue-Inducing Substances

“…Among therapeutics, adsorbent coatings for blood perfusion, 208-211 hemodialysis membranes, [212][213][214][215][216] blood oxygenators, 214 degradable drug delivery systems, medicated and soft contact lenses should be mentioned. [217][218][219][220][221] Implants include intraocular lenses, 222,223 artificial corneas, [224][225][226][227][228] coating for drainage tubes and stents, [229][230][231][232] vitreous humor replacements, 233 soft tissue substitutes/replacements, 126,234,235 burn dressing, [236][237][238][239][240][241] bone ingrowth sponges, 242 plastic surgery, [243][244][245] scleral buckling implants for retinal surgery. [246][247][248][249] Finally, as pure TE products, temporal artificial skin substitutes, membranes used to prevent postoperation adhesion and to promote healing, 250 HGs produced in vivo by using in situ photopolymerization, 9,10,35,37,202,…”