Collagen scaffold impregnated with borosilicate bioactive glass for endometrial healing

Artificial scaffolds that mimic the extracellular matrix (ECM) have promising applications in treating Asherman syndrome. In this study, we synthesized a bioactive glass (BG) by using the sol-gel method, and composite scaffolds with four different collagen concentrations (1, 2.5, 5 and 7.5 mg/mL) by freeze-drying approach. Next, we synthesized a novel collagen/BG composite by impregnating BG particles on the collagen scaffolds (CSBG1, CSBG2.5, CSBG5 and CSBG7.5 respectively). Mechanical analysis showed that the elastic modulus of CSBG5 reached 1 MPa which is comparable to soft tissues. Immunohistochemistry (IHC) results show that BG leads to a 1.93-fold increase in collagen secretion and a 3-fold increase in vascular endothelial growth factor (VEGF) secretion compared to the control groups. BG improves angiogenesis by a 4.9-fold increase in the number of branching points and a 6.5-fold increase in tube length. Immunofluorescence staining results revealed that CSBG5 has the greatest potential to be used as an endometrium scaffold since it has the highest cell viability and adhesion. Additional evidence includes increases in epithelial thickness, cytokeratin 7 (CK7) expressions, and the number of glands. Also, we observed that CSBG5 decreased calcification and inflammation. This study suggests that CSBG5 is a potential scaffold for uterine regeneration.