2024.12.17 《Mechanically Robust, Superlubricating and Antifouling Bilayer Nanocoating for Micro-Bioimplants via a Dual-Function Metal Coordination Approach》
在《ACS Nano》发表的研究中，针对微型化的植入式医疗器械，如血管内微型机器人和小直径血管移植物，其表面通常需要修饰具有卓越机械强度和良好润滑防污性能的纳米涂层，才能在生理环境下正常工作。研究者受到贻贝水下黏附科学领域，钒离子（VIII可通过金属-配体配位在贻贝厚度仅有~5 μm的角质层的机械强化中起到关键作用的启示。通过双功能金属配位策略开发了一种兼具高机械强度和强水化能力的纳米厚双层涂层（厚度~25 nm）。接触力学和界面分子力测量证明了 VIII 在构建双层涂层结构中的双重功能。作为受体，VIII 离子可以 1) 通过交联蛋白质网络内的配体来增强蛋白质底层机械强度； 2) 同时将设计的ABA三嵌段亲水聚合物的末端嵌段锚定到底层，形成水合顶层。归功于 VIII 螯合保障的牢固分层结构，这种纳米厚度的双层显示出卓越的承载和持久的超级润滑性能（即，在约 10 MPa 接触压力下，经过 100 个循环的摩擦测试，摩擦系数仍然保持在10-3量级），并且在复杂的生物流体环境中表现出不易被污染的能力。这项工作提出了一种将看似不相容的特性集成到超薄涂层中的新颖策略，有望为生物医学和生物工程应用的各种微型设备/机器定制多功能表面。
该文的第一作者为：项力，通讯作者为：曾宏波教授。
In research published in ACS Nano, for miniaturized implantable medical devices such as intravascular micro-robots and small-diameter vascular grafts, their surfaces typically require modification with nanocoatings possessing excellent mechanical strength and good lubrication and anti-fouling properties to function normally in physiological environments. Inspired by the scientific field of underwater adhesion of mussels, where vanadium ions (VIII) play a crucial role in mechanically reinforcing the cuticle of mussels, which is only ~5 μm thick, through metal-ligand coordination, a nanometer-thick bilayer coating (~25 nm thick) with both high mechanical strength and strong hydration ability was developed through a bifunctional metal coordination strategy. Contact mechanics and interfacial molecular force measurements demonstrated the dual function of VIII in constructing the bilayer coating structure. As a receptor, VIII ions can 1) enhance the mechanical strength of the protein substrate by crosslinking ligands within the protein network; 2) simultaneously anchor the terminal segments of a designed ABA triblock hydrophilic polymer to the substrate, forming a hydrated top layer. Thanks to the robust layered structure ensured by VIII chelation, this nanometer-thick bilayer exhibits excellent load-bearing and durable superlubrication properties (i.e., under a contact pressure of approximately 10 MPa, the friction coefficient remains in the order of 10-3 after 100 cycles of friction testing), and demonstrates resistance to contamination in complex biological fluid environments. This work proposes a novel strategy for integrating seemingly incompatible properties into ultrathin coatings, which is expected to enable the customization of multifunctional surfaces for various microdevices/machines in biomedical and bioengineering applications.
First author: Li Xiang
Corresponding author: Professor Hongbo Zeng