Biomaterials and Tissue Engineering Strategies for Conjunctival Reconstruction and Dry Eye Treatment

Abstract

The ocular surface is a component of the anterior segment of the eye and is covered by the tear film. Together, they protect the vital external components of the eye from the environment. Injuries, surgical trauma, and autoimmune diseases can damage this system, and in severe cases, tissue engineering strategies are necessary to ensure proper wound healing and recovery. Dry eye is another major concern and a complicated disease affecting the ocular surface. More effective and innovative therapies are required for better outcomes in treating dry eye. This review focuses on the regenerative medicine of the conjunctiva, which is an essential part of the ocular surface system. Features and advances of different types of biomolecular materials, and autologous and allogeneic tissue grafts are summarized and compared. Specifically, vitrigel, a collagen membrane and novel material for use on the ocular surface, offers significant advantages over other biomaterials. This review also discusses a breakthrough microfluidic technology, "organ-on-a-chip" and its potential application in investigating new therapies for dry eye.

Keywords: Biomaterials; Conjunctiva; Dry Eye; Ocular Surface; Organ-on-a-chip.

Figure 1

The preparation of collagen vitrigel and its appearance and structure. (a) Three-step preparation. (b) Crosslinking among collagen fibrils occurs during the vitrification process. (c) The final vitrigel is a transparent and thin membrane. (d) Transmission electron microscopy reveals the nanostructure of the vitrigel – the presence of densely and randomly packed collagen fibrils (adapted and modified from Guo et al. and Calderón-Colón et al. with permission from Elsevier)