A flexible and biocompatible bombyx mori silk fibroin/wool keratin composite scaffold with interconnective porous structure.

The paper describes the preparation of a porous bombyx mori silk fibroin (SF)/wool keratin (WK) composite scaffold with mimic structure and function for cartilage tissue engineering. A porous composite scaffold made from SF/WK in an appropriate concentration and mass ratio was prepared using a freeze-drying technique. Results showed that the composite scaffolds are water-insoluble; possess good mechanical properties, porosity above 80%, and pore size above 200 µm. Larger pore size and better connectivity of the composite scaffold than the pure SF scaffolds were contributed by the WK addition. The heat resistance and water-swelling of WK enhanced the thermal and mechanical properties of the composite scaffolds. In vitro cytotoxicity assessments showed cells with a good growth state, confirming no toxicity to the cells. The results of in vivo biocompatibility assessments exhibited that there is almost no inflammatory response in the implantation site tissue of the rats. The development of porous SF/WK composite scaffold has the potential in cartilage tissue engineering.

Sustainable Antibacterial Surgical Suture Using a Facile Scalable Silk-Fibroin-Based Berberine Loading System.

Medical sutures with sustainable antibacterial properties can effectively inhibit pathogens, thus avoiding the occurrence of surgical site infection and reducing the recurrence of patients resulting in postoperative death. This paper describes a facile scalable antibacterial surgical suture with sustainable antibacterial function and fair mechanical and biocompatible properties using a simple, efficient, and eco-friendly method. Silk filaments were braided into a core-shell structure using a braiding machine, and then silk fibroin (SF) films loaded with different percentages of berberine (BB) were coated onto the surface of the suture. The drug-loaded sutures performed a slow drug-release profile of more than 7 days. Retention of the knot-pull tensile strength of all groups was above 87% during in vitro degradation within 42 days. The sutures had no toxicity to the cells' in vitro cytotoxicity. The results of the in vivo biocompatibility test showed mild inflammation and clear signs of supporting angiogenesis in the implantation site of the rats. This work provides a new route for achieving a BB-loaded and high-performance antibacterial suture, which is of great potential in applications for surgical operations.

Silk fibroin added to calcium phosphate cement to prevent severe cardiovascular complications.

As a bone cement in vertebroplasty and kyphoplasty, calcium phosphate cement (CPC) has several advantages over polymethylmethacrylate (PMMA) including biomcompatibility, biodegradability and osteoconductivity. However, its decay properties raise the risk of pulmonary embolism and consequent cardiovascular complications. Animal experiments have demonstrated that the disintegration of CPC forming more emboli, especially microemboli, causes more severe cardiovascular deterioration than PMMA. Current efforts focus on the incorporation of organic proteins or polymers into CPC to improve its stability in fluids, by enhancing the hydroxyapatite (HA) formation and reducing the fluid penetration. Silk fibroin (SF) can regular the mineralization process and bond with HA to form fibroin-HA nanocomposites with increased gelation properties. SF also has excellent biomechanical, biocompatible and biodegradable properties, and is convenient and inexpensive to produce. We hypothesize that silk fibroin can be used as an additive to improve the cohesion of CPC and decrease its risk of cardiovascular complications in its application in veterbroplasty/kyphoplasty.