Mechanical and Optical Properties of Reinforced Collagen Membranes for Corneal Regeneration through Polyrotaxane Cross-Linking

Corneal transplantation is the widely accepted treatment to restore sight for corneal blindness. To date, because of the global donor cornea shortage, there is a need for alternatives to human donor corneas. Biocompatible collagen is an excellent candidate material for corneal repair in the view of biomimetics. Herein a class of polyrotaxane multiple aldehyde (PRA) cross-linkers based on the host-guest supramolecules of α-cyclodextrins and poly(ethylene glycol) is prepared to cross-link with collagen to fabricate materials for corneal repair. Aldehyde groups from rotaxanes and α-cyclodextrin units can synergistically improve the mechanical and optical properties of PRA cross-linked collagen membranes (Col-PRAs). Compared with counterparts cross-linked by traditional a cross-linker of 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide and N-hydroxy-succinimide, Col-PRAs have better mechanical properties, especially suture resistance as well as optical properties. In vivo lamellar keratoplasty results indicate that Col-PRAs not only can bear tight suturing on a rabbit cornea but also are prone to the remodeling of the epithelium and stroma of the cornea due to the outstanding cell adhesion and proliferation. These novel Col-PRAs exhibit great potential for use in the corneal regeneration.