Improving the mechanical properties of collagen‐based membranes using silk fibroin for corneal tissue engineering

Abstract

Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering.

Collagen membranes crosslinked by β-cyclodextrin polyrotaxane monoaldehyde with good biocompatibilities and repair capabilities for cornea repair

“…Suture experiments were conducted in vitro by hanging a 5 g weight, as previously described. 15 The 5 g weight was used to simulate the force of the suture. Before the surgery, the membrane was soaked in deionized water for more than 1 h until saturation.…”

“…Studies have reported the use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to crosslink collagen. 11,[13][14][15] EDC is a carboxyl and amine reactive zero length crosslinker, which reacts initially with the carboxyl group and forms an O-acylisourea intermediate. This intermediate reacts quickly with an amino group to form an amide bond and then releases an isourea byproduct.…”

Dextran Preserves Native Corneal Structure During Decellularization

“…An engineered corneal replacement has to withstand suturing during surgery (74) This article has been peer-reviewed and accepted for publication, but has yet to undergo copyediting and proof correction. The final published version may differ from this proof.…”

Biomaterials for Regenerative Medicine Approaches for the Anterior Segment of the Eye

“…An alternative use of silk fibroin has been as a reinforcing element in collagen-based membranes. [35] This has potential to take advantage of the increased cell interaction with the collagen component and the increased mechanical properties of the fibroin component.…”