A collagen film with micro-rough surface can promote the corneal epithelization process for corneal repair

Corneal disease is a major cause of blindness and keratoplasty is an effective treatment method. A freeze-dried collagen film (FD-Col) with micro-rough surface structure for corneal epithelial repair was reported in our previous studies. In this research, we conducted a more comprehensive study on the FD-Col film. Besides with excellent mechanical property and optical transparency, the FD-Col film also has good penetrating ability in nutrient solutions. The permeability coefficient of the FD-Col in NaCl and tryptophan solution is (2.58 ± 0.47) × 10^-6 cm²/s and (2.67 ± 0.13) × 10^-7 cm²/s, respectively. In addition, the morphology change of the FD-Col film before and after water absorption is relatively stable suggesting that this film can be fabricated with various dimensions easily. Moreover, corneal lamellar keratoplasty shows that the FD-Col film can be sutured in rabbit's ocular surface and the re-epithelization process in vivo is complete in about 12 days, and the transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization and keratoconus are not observed within 2 months. This FD-Col film, which can be prepared in large quantities and at low cost, should have potential application in corneal repair in the future.