Compression properties, in vitro degradation behavior and biocompatibility of porous Mg-1Zn-1Ca-0.5Mn scaffolds with different pore structures

Abstract

The pore shape and connectivity of porous Mg alloy scaffolds are of crucial significance for their mechanical properties, degradability, and biocompatibility. In this study, porous Mg-1Zn-1Ca-0.5Mn scaffolds with different pore structures were designed and manufactured using negative salt templates and infiltration casting to compare their properties. The results show that in terms of mechanical properties, the yield strength of the porous spherical scaffold, reaching 13.5 MPa, is higher than that of the porous cubic scaffold (4.9 MPa). Regarding degradability, the corrosion rate of the spherical scaffold (0.69±0.09 mm/year) is lower than cubic scaffold (1.09±0.12 mm/year), For biocompatibility, the pore structure of the porous spherical scaffold shows better cell adhesion compared to the cubic scaffold. The better mechanical property of the spherical scaffold can be attributed to the unique connectivity of its spherical pore structure, which enables more efficient stress dispersion, thus strengthening the overall mechanical strength. The better corrosion resistance is because the spherical scaffold has the more uniform pores and less contact area with the HBSS. As for biocompatibility, the uniform curvature of the spherical pore edges minimizes stress concentration, creating a stable mechanical environment for cells. The spherical shape closely aligns with the natural morphology of cells, which may promote cell spread and migration. Also, the continuous edges and absence of sharp corners in spherical pores reduce the mechanical stress during cell adhesion and have certain effects on enhancing cell adhesion and proliferation.