Deformable yolk-shell nanoparticles for shear-driven tribocatalytic thrombolysis and cascade nanozyme-enabled...

Thrombotic diseases continue to pose a significant clinical challenge with high mortality and recurrence rates following thrombolysis. Herein, we propose endogenous shear stress-activated tribocatalytic thrombolysis via a dynamic S-scheme heterojunction and thrombosis recurrence-prevention via cascade nanozyme catalysis. Specifically, deformable yolk-shell nanoparticles (NPs) composed of bismuth ferrite-coated flexible mesoporous organosilica (fBF) yolks and manganese-doped cerium oxide (CeMn) shells, with fucoidan subsequently grafted onto the surface, are referred to as fBF@CeMn-Fu. Local shear stress induces high-frequency friction and collision between the fBF yolks and the CeMn shells, and tribocatalytic activity is promoted through friction contact area expansion via the deformability of mesoporous organosilica, S-scheme heterojunction between fBF and CeMn, and Mn-O-Ce electron channel and oxygen vacancies in CeMn. These deformability/component engineering and tribovoltaic/piezoelectric effect collectively boost electron-hole separation, overall redox capacity and generation of reactive oxygen species for effective thrombus dissolution. Upon completion of thrombolysis, Mn doping acts as a bidirectional electron pump, accelerating electron transfer and augmenting the superoxide dismutase (SOD) and catalase (CAT) activity of CeMn nanozyme. This SOD-CAT cascade catalysis effectively mitigates oxidative stress and inflammatory microenvironment associated with thrombosis, laying a foundation to prevent thrombosis recurrence. In a carotid artery thrombosis model, combination of tribocatalysis and fucoidan grafting achieve nearly complete thrombus dissolution. Subsequently, nanozyme cascade catalysis restores endothelial function, upregulates nitric oxide synthase expression, promotes endothelial healing, thereby suppressing platelet activation and thrombosis recurrence. The deformable yolks-enhanced tribocatalysis and nanozyme cascade offer an effective strategy for thrombosis management with precise dissolution and recurrence prevention.