Porous and nonporous silk fibroin (SF) membranes wrapping for Achilles tendon (AT) repair: Which one is a better choice?

Two types of silk fibroin (SF) membranes were developed for tendon repair: porous and nonporous SF membranes. The objective of this study was to compare the efficiency of these two films according to the ability of tendon regeneration using a rat Achilles tendon (AT) rupture suture wrapping model. The in vitro tests were conducted, and theSF membranes were proved to be with ultimate-biodegradability, good-biocompatibility and without toxicity. In vivo, 12 Sprague Dawley rats were used to create a rat AT rupture suture model wrapped by SF membranes. They were randomly divided into six groups. The results revealed that the nonporous SF membrane wrapping group was shown to reduce the inflammatory effect and induce the proliferation of fibroblast-like cells at one week and four weeks post-operatively. After four weeks, the nonporous SF membrane wrapping group exhibited more organized collagen structures and had increased expression of tendon repair proteins. Hence, our nonporous SF membrane improved the efficacy of tendon regeneration by decreasing inflammatory cells, growing fibroblast-like cells, and promoting extracellular matrix production. Nonporous SF membrane can, therefore, be regarded as a better functional membrane for tendon repair.