Abstract: Bone defect repair remains a troubling problem in clinical orthopedics, which involves complex biological processes. Calcium phosphates (CaPs) have been widely used owing to their advantage of biocompatibility. However, single component and traditional fabrication methods cannot meet the requirements of bioadaptability during the tissue repair process. In this work, 0%, 5%, 15%, 25% wt% of BG-TCP (bioactive glass-β-tricalcium phosphate) bioresorbable scaffolds with triply-periodic minimal surfaces (TPMS)-gyroid structure were prepared by the stereolithography (SLA) technology. TPMS-gyroid structure provided an accurate mimicry of natural bone tissue, and the incorporation of BG improved the compressive strength of β-TCP matrix, matched with the defective bone (2-12 MPa). Rapid but tunable degradation kinetics (compared with pure TCP) of BG enabled the BG-TCP system to sh8ow adaptable biodegradability to new bone generation. In vitro studies have shown that composite scaffolds have better mechanical properties (7.82 MPa), and can released appropriate contents of calcium, phosphorous, and magnesium ions, which promoted the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and angiogenic ability of endothelial progenitor cells (EPCs). Moreover, the in vivo assessment of rat femoral defect revealed that TPMS-structure-based TCP scaffolds accelerated bone ingrowth to the pores. Moreover, BG-TCP scaffolds, especially 15BG-TCP group, exhibited superior bone regeneration capacity at both 4 and 8 weeks, which achieved an optimal match between the rate of material degradation and tissue regeneration. In summary, this study provides insight into influences of bioactive components (BG) and bionic structures (TPMS) on the physical-chemical properties of materials, cell behavior and tissue regeneration, which offers a promising strategy to design bioadaptive ceramic scaffolds in the clinical treatment of bone defects.

Key words: Bioactive glass, Tricalcium phosphate, Triply periodic minimal surfaces, Stereolithography, Osteogenesis