Strontium chondroitin sulfate/silk fibroin blend membrane containing microporous structure modulates macrophage responses for guided bone regeneration

A membrane used for guided bone regeneration (GBR) serves as a bioactive compartment rather than a physical barrier. However, the pure membrane may not provide an optimal microenvironment for bone formation and remodeling. Here, a novel strontium chondroitin sulfate/silk fibroin (SrCS/SF) blend membrane containing microporous structure was fabricated. By increasing incorporation content of SrCS, SrCS/SF membranes exhibit better mechanical properties and higher water retention capacity. In vitro results reveal that higher content of SrCS membranes facilitate osteoblasts proliferation. The evaluation of the osteoimmunomodulatory effects of the membranes reveals that SrCS/SF membranes should have positive effects on modulating the osteoimmune response of macrophages, by downregulating the expression of pro-inflammatory cytokines and the expression of degradation related catabolic genes and upregulating osteogenic factors. It is therefore believed that the developed SrCS/SF membranes should be potentially used as multifunctional bioactive GBR membranes.