Electrospun the oriented silk fibroin/ bioactive glass @ silk fibroin/ polycaprolactone composite bi-layered membranes for guided bone regeneration

Guided bone regeneration (GBR) technology has been extensively used in the treatment of alveolar bone defects. However, existing GBR membranes still have great shortcomings in terms of biological activity and regeneration potential. In order to improve the performance of existing GBR membranes, based on the principle of GBR, this study starts from two aspects of material and structure, adding BG particles with good biological properties and introducing directional structure to construct a new type of double-layer composite fiber membrane, which can not only achieve the barrier function, but also induce the directional migration and differentiation of osteoblasts, so as to play the role of bone tissue regeneration and repair more efficiently. In this study, a bi-layer composite GBR membrane with oriented structure of silk fibroin (SF) / bioactive glass (BG) @ silk fibroin (SF) / polycaprolactone (PCL) was prepared by high-speed electrospinning technology, which achieved the dual functions of bone regeneration and barrier. The morphology, mechanical properties, secondary structure, biocompatibility and bioactivity of the oriented bi-layer composite membranes were studied systematically. The results showed that the fiber diameter and the pore size of SF/PCL composite membranes were obviously smaller than that of SF/BG composite membranes. Compared with SF and SF/BG composite membranes, the Young's modulus and tensile stress of the oriented SF/BG composite membranes is significantly increased, but the elongation at break is relatively decreased. The water contact angle of the material significantly decreased after the addition of BG particles and the introduction of orientated structure, which greatly improved the hydrophilicity of the composite membranes. Furthermore, the oriented SF/BG@SF/PCL exhibited higher cell adhesion and proliferation compared with the disordered SF/BG fiber membranes, and the introduction of BG particles significantly enhanced osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Besides, the barrier effect of the SF/PCL membrane was verified by L929 cells. The relatively dense structure leads to a good barrier effect as well as the obvious proliferation on the cells. This bi-layer composite SF/BG@SF/PCL membrane is a competitive candidate in the field of GBR technology and bone regeneration.