Nanotechnology in regenerative ophthalmology

Abstract

In recent years, regenerative medicine is gaining momentum and is giving hopes for restoring function of diseased, damaged, and aged tissues and organs and nanotechnology is serving as a catalyst. In the ophthalmology field, various types of allogenic and autologous stem cells have been investigated to treat some ocular diseases due to age-related macular degeneration, glaucoma, retinitis pigmentosa, diabetic retinopathy, and corneal and lens traumas. Nanomaterials have been utilized directly as nanoscaffolds for these stem cells to promote their adhesion, proliferation and differentiation or indirectly as vectors for various genes, tissue growth factors, cytokines and immunosuppressants to facilitate cell reprogramming or ocular tissue regeneration. In this review, we reviewed various nanomaterials used for retina, cornea, and lens regenerations, and discussed the current status and future perspectives of nanotechnology in tracking cells in the eye and personalized regenerative ophthalmology. The purpose of this review is to provide comprehensive and timely insights on the emerging field of nanotechnology for ocular tissue engineering and regeneration.

Keywords: Cell reprogramming; Electrospun nanofibers; Immunomodulators; Nanoscaffolds; Nanotopography; Ocular regeneration; Self-assembled peptides; Stem cells.

Fig. 1.

Schematic representations of nanoscaffolds including electrospun nanofibers, self-assembled peptides and nanotopographies used for ocular regeneration.

Fig. 2.

SEM images of RPE cells on PLGA and collagen nanofibrillar membranes, PLGA films and cover glass after 11 days of incubation. The RPE cells formed in vivo-like monolayer of hexa/polygonal cells (shown on x600 and x1500) with long, sheet-like microvilli (shown on x10000) on the PLGA and collagen nanofibrous membranes. Figure is adapted with permission from reference [91].

Fig. 3.

Rabbit corneal fibroblasts grown on aligned fibers expressed less α-SMA expression than those grown on unaligned fibers and tissue culture dishes. Top row: Cells cultured on culture dish, unaligned and aligned electrospun fibrous scaffolds. Middle row: SEM images of the morphology of the cells. Bottom row: IF images of cells. Cell nuclei are labeled with CYTOX green; α-SMA is labeled with rhodamine (red). Arrows indicate the direction of fiber alignment. Figure is adapted with permission from reference [125].

Fig. 4.

Schematic representation of the formation of self-assembled nanofiber-based nanogels made of LMWG molecule. LMWG molecule was conjugated with a RGSD peptide via a maleimide linker molecule and then formed into nanogels by self-assembly. Figure is adapted with permission from references [163].

Fig. 5.

Schematic representation of different types of nanoparticles used as gene delivery carriers for ocular regeneration.