Abstract

In this work, double-layer heterogeneous calcium alginate scaffolds were designed for alveolar bone defects where the outer layer featured high hardness and slow degradation, and the inner layer characterized by large pores and rapid degradation. The morphology of the calcium alginate scaffold was akin to that of bone defects, and its direct implantation reduced the operation time. A higher concentration of calcium alginate resulted in smaller pores and slower degradation. Calcium alginate 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 calcium alginate did not promote the aggregation of inflammatory cells nor 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.