Mucus cell-inspired microstructure lubricative gel surface: Secretory, trap-locked and dual antithrombotic

Blood-contacting medical devices are essential for sustaining cardiovascular patients' lives. Advanced antithrombotic materials serve as pivotal components to enhance device reliability, as non-physiological hemodynamics and materials provoke thrombus that compromises device functionality and patient safety. Liquid-infused surfaces (LIS), as a bioinert surface modification technology, have been proven effective in inhibiting thrombus formation by suppressing the adhesion of plasma components. However, the loss of lubricants under hemodynamic shear stresses imposes limitations on their clinical application. Enhancing the durability of LIS in blood-contacting environments remains a critical challenge. Natural fluid-retentive systems, such as mucus cells, utilize secretory mechanisms and microvilli structures to anchor fluids effectively. Inspired by these biological paradigms, this study engineered a microstructured lubricant-secreting antithrombotic surface (ms-LSAS) to address the sustained antithrombogenicity requirements of medical devices. The gel-based laser-induced periodic surface structures (LIPSS) fabricated via femtosecond laser and soft lithography mitigate surface lubricant displacement caused by hemodynamic shear stress through enhanced surface area and capillary forces, while continuous secretion of the gel ensures sustained lubricant replenishment. Furthermore, the surface topographic microstructures maintain platelet adhesion suppression through steric hindrance even under lubricant-depleted conditions. Synergistic effects of the lubricating layer and flexible submicron topology suppress protein adsorption and platelet adhesion, achieving robust static and dynamic antithrombogenicity. ms-LSAS can mitigate the critical challenge in blood-contacting devices: thrombus formation induced by platelet activation on material surfaces under non-physiological hemodynamics. This bioinspired strategy may thus pave the way for achieving anticoagulation equilibrium in next-generation medical implants.