An embolism-free nonfouling hydrogel coating with high toughness and lubricity for intravascular medical devices via chain-entanglement mediated topological gelation

Hydrogel coatings have become indispensable for advanced interventional devices owing to their exceptional lubricity, antithrombogenicity, and antibacterial performance. However, clinical adoption has been hindered by the risk of polymer embolism resulting from coating delamination in vascular systems. Herein, we report an embolism-free hydrogel coating strategy based on chain-entanglement-mediated topological gelation to address this limitation. Through an interface-regulated polymerization process, we fabricate a robust zwitterionic hydrogel coating stabilized by interfacial interlinking and enhanced polymer chain entanglement. This design delivers outstanding long-term antimicrobial and antithrombogenic properties and achieves high toughness, ultra-low friction, and wear resistance. Notably, the chain-entangled topological hydrogel exhibits a unique fail-safe mechanism: upon detachment, it undergoes spontaneous aqueous dissolution rather than forming hazardous debris. This approach can potentially reduce life-threatening complications in interventional therapies by eliminating the risk of polymer-induced embolism.