Embolic microspheres in interventional oncology and vascular therapy: Moving beyond vessel occlusion to multifunctional therapeutics

Embolic microspheres are pivotal in interventional oncology and vascular embolization, providing targeted occlusion and therapeutic delivery with minimal systemic toxicity. Recent progress in material science has enabled the design of microspheres from natural polymers, synthetic polymers, and inorganic materials, each offering unique properties such as biodegradability, biocompatibility, radiopacity, and drug-loading capacity. Advancements in fabrication techniques, including microfluidics, electrostatic spraying, and emulsification, have further refined their size uniformity, functionalization, and clinical safety. Classification based on degradability, size, therapeutic function, and imaging visibility highlights their ability in transarterial chemoembolization, radioembolization, and hemostatic interventions. This review discusses the current state of embolic microsphere development, with an emphasis on material innovation, preparation strategies, and applications. Finally, challenges and future directions are outlined to accelerate their transition from experimental platforms to next-generation embolic agents for precision medicine.