| Abstract Scope |
Transarterial embolization relies on particulate embolics for controlled vascular occlusion, yet outcomes remain difficult to predict because transport, packing, and flow shutdown depend on particle size, deformability, and time-dependent interactions. Here, we present an adaptive, radiopaque embolic platform based on tantalum-loaded calcium alginate microspheres and quantify how ion-triggered material evolution governs embolization performance. Microspheres with varied CaČ⁺ crosslink densities underwent rapid Na⁺-induced volumetric expansion in saline and whole blood, with distinct kinetic regimes. Expansion persisted under confinement and flow, demonstrating physiologically relevant adaptation during transport and lodging. Sharp-tip AFM and colloidal-probe FluidFM revealed hydration-associated softening and probe-dependent moduli, consistent with heterogeneous composite microstructure. In a multigenerational microvascular phantom, adaptive microspheres achieved substantially greater outlet flow suppression than non-adaptive controls despite only modestly more distal embolization fronts. These results establish adaptive calcium alginate microspheres as tunable embolics linking crosslink density, material evolution, mechanics, and occlusion efficacy. |