Rapid osteointegration with a strontium-containing hydroxyapatite coating on tantalum by activating Itga6-PI3K/AKT signaling pathway

Owing to its excellent biocompatibility, tantalum has the potential to replace titanium as a new mainstream bone-repair material. However, it was recognized as an inert metal. Therefore, it is necessary to improve the bioactivity of tantalum through surface modification to achieve more stable osseointegration. The key to designing bone repair materials is to imitate the physical structure and chemical composition of natural bone. In this study, a microscale strontium-containing hydroxyapatite (Sr + HA) coating was loaded onto a tantalum surface using a hydrothermal method, which improved the protein adsorption ability and hydrophilicity of tantalum. The incorporation of Sr also promoted the release of Sr²⁺ and Ca²⁺. Furthermore, the results of in vitro and in vivo experiments showed that Sr + HA had good biocompatibility and bone integration. The research and development of biomaterials needs to be based on an understanding of the mechanism of action between materials and cells. Combined with transcriptomics and label-free quantitative proteomics analyses, it was confirmed for the first time that Sr + HA could activate the PI3K/AKT pathway by up-regulating Itga6 to promote the osteogenic differentiation of cells, thereby providing a theoretical basis for the development of tantalum-based implants with excellent osseointegration properties.