Feasibility of Polylactic Acid-Polycaprolactone-Blended Microspheres in Transarterial Embolization Therapy

Transarterial embolization (TAE) is a minimally invasive endovascular therapy used for tumor devascularization, hemorrhage control, and the treatment of vascular malformations. In particulate TAE, embolic microspheres are delivered through microcatheters to occlude target vessels, and the clinical outcome strongly depends on the particle uniformity, deliverability, mechanical compliance, and intravascular biocompatibility. However, currently available biodegradable embolic materials often degrade too rapidly, leading to premature recanalization, and their acidic degradation products may induce local inflammatory responses. Therefore, degradable microspheres with tunable mechanical properties and a controllable degradation behavior are needed. In this study, polylactic acid/polycaprolactone (PLA/PCL) blend microspheres were fabricated using an emulsion solvent evaporation method with varying PLA/PCL ratios and systematically evaluated. Incorporation of PCL modulated microsphere surface morphology and improved particle deformability, while compression testing demonstrated a progressive reduction in apparent Young's modulus compared with neat PLA. Hemolysis and cytotoxicity assays confirmed that the P-(LA/CL)-73 formulation exhibited nonhemolytic behavior and good cytocompatibility. In addition, P-(LA/CL)-73 demonstrated enhanced thrombus formation, controlled and sustained degradation, and improved distal embolization performance in a 3D-printed in vitro vascular model. These findings suggest that P-(LA/CL) blend microspheres, particularly P-(LA/CL)-73, represent a promising biodegradable embolic platform with tunable mechanical and degradation properties for next-generation TAE applications.