The Experimental Study of Double-Layer Heterogeneous CA Scaffold in Promoting the Surface Shape Recovery and Internal Osteogenesis of Alveolar Bone

In this work, double-layer heterogeneous CA scaffolds were designed for alveolar bone defects. The outer layer featured high hardness and slow degradation, and large pores and rapid degradation characterized the inner layer. The CA scaffold morphology was akin to bone defects, and its direct implantation reduced the operation time. A higher concentration of CA resulted in smaller pores and slower degradation. CA can promote the formation of mineralized nodules and the expression of genes related to mineralization without inducing cytotoxic effects. It also promoted the expression of cellular inflammatory factors, potentially through the TLR4 pathway. In vivo studies confirmed that CA did not promote the aggregation of inflammatory cells or the expression of inflammatory factors. In conclusion, the scaffold's characteristics of high surface hardness and slow degradation were beneficial for surface osteogenesis and maintaining the defect's shape and osteogenic space. Conversely, rapid internal degradation favors the formation of bone tissue.