In vitro and in vivo degradation of silk fibers degummed with various sodium carbonate concentrations

[Display omitted] •The nanofibril structure and mechanical properties of silk are significantly affected by the NaCO3 concentration.•The NaCO3 concentration allows a wide control of the silk fiber’s degradation in vitro and in vivo.•The fibrils or fragments, according to NaCO3 concentration, are degraded from the silk fibers.•The degummed silks show good biocompatibility, allowing host cell adhere, growth and new blood vessels.•The in vivo degradation of degummed silk is through the circulating macrophages. Silk fiber-based scaffolds have attracted growing attentions as promising candidate biomaterials for tissue regeneration and repair due to its unusual features. However, the slow degradability of silk fiber endowed by hierarchical structure has restricted its clinical application. Degumming is a routine process to remove sericin which allows a controllable destruction on the structure of silk fibers, thus tunes its degradation. In the present study, an attempt to tune the biodegradation period of silk through degumming with various sodium carbonate concentrations was studied. The results showed that the weight loss, surface erosion and the decrease of mechanical properties of silk fibers depended on the sodium carbonate concentrations. Mostly, the degradation behavior of degummed silk fibers could be tuned through degumming conditions, thus to match the diverse needs of tissue regeneration with specific functional requirements and repair rates. The implantation of degummed silk fibers caused mild inflammatory response, suggesting good compatibility. The information gained in the present study is important for the further development of silk fiber-based scaffolds with microfibrous surface, mechanical properties and biodegradation tuned to specific biomedical applications.