Silk fibroin (SF) from the silkworm Bombyx mori is a fibrous protein identified as a widely suitable biomaterial due to its biocompatibility, tunable degradation, and mechanical strength. Various modifications of SF protein can give SF fibers new properties and functions, broadening their applications in textile and biomedical industries. A diverse array of functional modifications on various forms of SF has been reported. In order to provide researchers with a more systematic understanding of the types of functional modifications of SF protein, as well as the corresponding applications, we comprehensively review the different types of functional modifications, including transgenic modification, modifications with chemical groups or biologically active substance, cross-linking and copolymerization without chemical reactions, their specific modification methods and applications. Furthermore, recent applications of SF in various medical biomaterials are briefly discussed.

Here, we report a novel chitosan hydrogel membrane (CHM) created by an improved electrophoretic deposition. Unlike a traditional CHM by electrophoretic deposition, the CHM was formed on a nanoporous film as a barrier using a homemade device at a high DC voltage (60 VDC). The CHM maximum recovery of 81.7% could be achieved after 1h of electrophoretic deposition. The transparent CHM with an elongation of 42.46% and swelling index of 538.86% was a mixture of type I and type II crystal structures. SEM revealed that the CHM had an irregular net structure. The CHM was sufficient for L-929 mouse fibroblast cell adhesion and growth. To demonstrate immunocompatibility with host tissues, H&E and TGF-β1 were observed and the expressions of TNF-α and NF-κB were measured up to 3weeks post-implantation. Although these scaffolds demonstrated an initial pro-inflammatory response, the amount of inflammatory cells and the expressions of TGF-β1 returned to baseline control values at 3weeks. The expressions of TNF-α and NF-κB had no significant difference between the experimental and control groups. Animal experiments showed that the CHM did not incite serious inflammatory reactions. Thus, the CHM is a promising medical biomaterial candidate for loading appropriate cells for use as artificial skin or in transplantation.

The clinical importance of material loss at the head-stem junction is unknown. Comparison of retrievals with different stem types can provide the opportunity to understand the importance of the taper junction. This was a case-control study involving 20 retrieved 36 mm metal-on-metal Pinnacle (DePuy) hips that were paired with either a Corail (n = 10) or S-ROM (n = 10) stem. The median head taper material loss rate for the Corail group was 0.238 (0.0002-2.178) mm(3)/year and was significantly greater than the S-ROM group (p = 0.042), which had a median material loss rate of 0.132 (0.015-0.518) mm(3)/year. The only significant difference between the groups was the stem taper roughness and length: this was rougher and shorter for the Corails. Long and smooth stem taper designs are preferred when used in conjunction with metal heads.