Enhancing the biological functionality of poly (lactic‐co‐glycolic acid) cage‐like structures through surface modification with micro‐ and nano‐sized hydroxyapatite particles

Abstract Biomaterials with exceptional performance are crucial for addressing the challenges of complex bone regeneration. Compared with traditional three‐dimensional scaffolds, injectable microspheres enable new strategies for the treatment of irregular bone defects. Biodegradable poly (lactic‐co‐glycolic acid) has found widespread applications as microcarriers of drugs, proteins, and other active macromolecules. Applied to the surface of poly (lactic‐co‐glycolic acid) cage‐like structures (PLGA‐CAS), hydroxyapatite (HA) effectively reduces inflammation while enhancing biological effects. In this study, we loaded the surface of PLGA‐CAS with micro‐ and nano‐hydroxyapatite particles, referred to as μHA/PLGA‐CAS and nHA/PLGA‐CAS, respectively. Subsequently, their material characteristics and biological effects were assessed. The incorporation of hydroxyapatite onto PLGA‐CAS resulted in enhanced surface roughness and hydrophilicity, coupled with improved thermal stability and delayed degradation. Furthermore, μHA/PLGA‐CAS induced osteogenic differentiation of osteoblast precursor cells, while nHA/PLGA‐CAS improved endothelial cell adhesion and stimulated angiogenic differentiation in vitro. Collectively, these findings suggest that μHA/PLGA‐CAS and nHA/PLGA‐CAS, each with distinct characteristics, hold significant potential for application as microcarriers in various biomedical contexts.