Copper Integrated PDA-TA Nanocoating via One-Step Rapid Polymerization on Titanium for Anti-Thrombotic and...

Long-term clinical translation of left ventricular assist devices (LVADs) is severely hampered by thromboembolism and device-related infection, both originating from inadequate biocompatibility of the device-blood interface. Current titanium surface modifications fail to simultaneously deliver durable antithrombotic and antibacterial performance, while conventional polydopamine-copper (PDA-Cu) coatings suffer from inherent limitations. Herein, we report a one-step rapid co-polymerization strategy based on mussel-inspired polyphenol chemistry to fabricate a copper-integrated polydopamine/tannic acid nanocoating on titanium (Ti/PDT(Cu)). By incorporating tannic acid rich in catechol/pyrogallol moieties, we achieve synergistic acceleration of dopamine oxidative polymerization with copper ions, dramatically shortening the fabrication time to 8 h (vs. 24 h for traditional PDA coatings). This process simultaneously constructs a robust dual-crosslinked network through covalent/hydrogen bonds and metal-phenolic coordination, exhibiting a uniform nanoscale-roughened structure. Comprehensive physicochemical characterizations confirm homogeneous coating deposition, excellent hydrophilicity, uniform Cu distribution, and superior long-term structural stability (95.68% thickness retention after 7 days of physiological immersion). The optimized coating displays broad-spectrum and durable antibacterial activity, with 92.79% and 89.73% reduction of E. coli and S. aureus at 24 h, respectively, and retains >89% antibacterial efficacy after 7 days of continuous elution (n = 3, * p< 0.05). Moreover, the coating enables stable and sustained catalytic nitric oxide generation (43.85 ± 2.36 μM cumulative release over 14 days) that mimics endothelial function, resulting in 69.4% inhibition of platelet adhesion and an ultralow hemolysis ratio of 0.97% (n = 3). Critically, it maintains excellent cytocompatibility with L929 fibroblasts (>90% cell viability after 72 h co-culture). This work addresses key limitations of conventional PDA-based functional coatings, realizes synergistic antithrombotic and antibacterial dual functions showing great potential for blood-contacting cardiovascular device applications, and provides a facile and robust surface engineering platform for long-term implantable cardiovascular devices.