Boric acid-crosslinked polyvinyl alcohol concave round cake-like microspheres for enhanced doxorubicin delivery in chemoembolization therapy

Transcatheter arterial chemoembolization (TACE) is considered a critical treatment for hepatocellular carcinoma, but conventional embolic agents remain challenging in drug release profiles and embolization precision. Herein, we fabricated polyvinyl alcohol (PVA) concave round cake-like microspheres crosslinked with boric acid (H 3 BO 3 ) for enhanced drug delivery and embolization. PVA microspheres loaded with doxorubicin (DOX) were constructed using a crosslinking-assisted solvent evaporation method, with size control through calibrated needles. The microspheres were characterized for morphology, drug loading, release kinetics, and mechanical properties using techniques such as SEM, FTIR, TGA, XRD, and compression tests. The microspheres demonstrated over 85 % drug encapsulation efficiency and a maximum drug loading of 66.8 % w/w. In vitro cytotoxicity assays showed significant dose-dependent anticancer activity against HepG2 cells. Furthermore, the concave round cake-like microspheres exhibited excellent biocompatibility with human umbilical vein endothelial cells (HUVECs) and minimal hemolytic activity. Embolization simulations confirmed effective vascular occlusion. These results suggest that DOX-loaded PVA microspheres, with controlled drug release and robust embolic efficacy, represent a promising dual-function agent for TACE.