Optimizing monodisperse bioactive Si‒B‒Ca nanoglass for angiogenesis and wound repair

Bioactive glasses (BGs) have been important tissue repair materials due to their biomimetic biomineralization and cellular activation. Tailoring the network of silicate glass using different elements, such as boron, has been instrumental in enhancing its bioactivity for specific applications in tissue engineering. However, the previous studies were focused on the bone tissue repair, but few on the effect of boron-incorporated network and monodisperse nanostructure of BG (BGNB) on angiogenesis and soft tissue wound. Herein, we report the synthesis of monodisperse BGNB with different boron (0‒12 mol%) using template-assisted sol‒gel process, and investigated their effect on the structure, apatite formation, wound tissue cellular activities, and wound repair performance. The results indicate that boron doping has a minimal effect on nanoparticle morphology and size, while preserving the amorphous phase structure of bioactive glass nanoparticles (BGN). Upon immersion in simulated body fluid for 1 day, the formation of needle-like crystalline hydroxyapatite (HA) was observed. Due to the weaker chemical stability of B‒O bonds compared to Si‒O bonds, an accelerated degradation rate of BGN can be achieved, thereby modulating the mineralization process. Over prolonged mineralization periods, BGNB exhibited the superior in vitro bioactivity with the promotion of HA deposition and growth on the surface. Furthermore, BGNB possesses favorable biocompatibility, anti-inflammatory activity, and enhanced ability to promote human umbilical vein endothelial cells migration and upregulate expression of VEGF. In vivo study confirmed that BGNB can significantly accelerate wound healing and improve the quality of tissue repair by promoting angiogenesis and collagen deposition. This work demonstrated that BGNB can enhance in vitro bioactivity and promote wound healing, making it a promising candidate for wound repair material.