Advancing Osteoporotic Bone Regeneration Through Tailored Tea Polyphenols Functionalized Micro‐/Nano‐ Hydroxyapatite Bioceramics

Abstract Efforts to develop advanced bone substitutes for effective bone regeneration in substantial defects have led to the fabrication of tissue‐engineered scaffolds. These scaffolds, featuring hierarchical structures, specific chemical compositions, and functional qualities, are essential in mimicking native bone tissue. Inspired by the biomineralization process, hydrothermal treatment is used to synthesize micro‐/nano‐hydroxyapatite bioceramics functionalized with tea polyphenols (TP‐nwHA), closely resembling the structure of bone‐like apatite induced by hydroxyapatite bioceramics in vivo. The in vitro results demonstrate TP‐nwHA's superior biocompatibility, enhancing cell proliferation and adhesion. Furthermore, TP‐nwHA scaffolds significantly influence mesenchymal stem cells, promoting osteogenic differentiation while inhibiting osteoclastogenic differentiation. The upregulation of osteogenic proteins BMP2 and ITGB1, along with the downregulation of osteoclastic proteins FGF21 and IGFBP1, demonstrate the synergistic effect of the biomimetic structure and polyphenols on the activation of the MAPK signaling pathway. In vivo, TP‐nwHA showe early angiogenic capabilities, leading to improved bone regeneration in critical‐size femoral bone defects in osteoporotic rats. Histological staining confirms the complete bridging of defects with new bone tissue in the TP‐nwHA group, and nanoindentation tests indicate the formation of mature mineralized bone tissue. Collectively, these findings suggest a novel strategy for fabricating bone‐mimicking constructs with potential applications in disease modeling.