Facile method to prepare silk fibroin/hyaluronic acid films for vascular endothelial growth factor release

• A facile process was reported to prepare the HA/SF films in all aqueous solution.
• The HA content played the leading role in controlling the β-sheet structure formation at 37 °C.
• The HA/SF films had a rapid VEGF release with 22.3% VEGF release in 96 h.

A facile approach was proposed to prepare silk fibroin (SF) and hyaluronic acid (HA) composite films from aqueous solution without crosslinking or any post treatment. Only by controlling the HA content and film formation temperature during the film casting, the HA/SF films with different composition were prepared. The films were then characterized by structural characteristics, thermal stability, morphology, water stability, water absorption, mechanical properties. After immersing in water for 24 h, all of the films showed good structural integrity. The degradation rate of the HA/SF films in protease XIV can be controlled by changing the film formation temperature and HA content. Decreasing the temperature and adding HA resulted in the rapid release of VEGF (vascular endothelial growth factor) from the HA/SF films. Overall, the 5% HA/SF films formed at 37 °C with more rapid VEGF release exhibited great potential in drug delivery, especially when the rapid vascularization was needed.