Evolution of embolization microspheres from physical occlusion to theranostic modulation in hepatocellular carcinoma treatment

Primary liver cancer remains the leading cause of global mortality, with hepatocellular carcinoma (HCC) accounting for the majority of cases arising from chronic inflammation and cirrhosis. Transarterial interventions including chemoembolization and radioembolization are standard therapies for patients with unresectable diseases. However, the efficacy of traditional embolic agents is frequently compromised by a lack of intrinsic imaging visibility and permanent vascular occlusion. Furthermore, conventional approaches often induce a hypoxic response that paradoxically drives angiogenic and immunosuppressive pathways within the tumor microenvironment. This review examines the paradigm shift toward engineering multifunctional microspheres designed to overcome these translational barriers and transform passive vessel blockers into active modulators of the tumor ecosystem. We discuss advancements in microfluidic fabrication technologies that enable the precise control of particle size and architecture, along with the transition from inert polymers to bioactive and biodegradable scaffolds capable of on-demand drug release. The integration of theranostic functionalities, including multimodal imaging guidance and physical actuation via hyperthermia, is evaluated in the context of synergizing locoregional embolization with systemic immunotherapy. These next-generation microspheres have the potential to reverse immunosuppression and enhance therapeutic precision to improve the clinical outcomes in liver cancer management.