High-density zwitterionic polymer brushes exhibit robust lubrication properties and high antithrombotic efficacy in blood-contacting medical devices

Xinzhong Song , Jia Man , Yinghua Qiu , Jiali Wang , Jianing Liu , Ruijian Li , Yongqi Zhang , Jianyong Li , Jianfeng Li , Yuguo Chen

School of Mechanical Engineering, Shandong University

Journal：《ACTA BIOMATERIALIA》

Abstract：

High-performance catheters are essential for interventional surgeries, requiring reliable anti-adhesive and lubricated surfaces. This article develops a strategy for constructing high-density sulfobetaine zwitterionic polymer brushes on the surface of catheters, utilizing dopamine and sodium alginate as the primary intermediate layers, where dopamine provides mussel-protein-like adhesion to anchor the polymer brushes to the catheter surface. Hydroxyl-rich sodium alginate increases the number of grafting sites and improves the grafting mass by more than 4 times. The developed high-density zwitterionic polymer brushes achieve long-lasting and effective lubricity (μ<0.0078) and are implanted in rabbits for four hours without bio-adhesion and thrombosis in the absence of anticoagulants such as heparin. Experiments and molecular dynamics simulations demonstrate that graft mass plays a decisive role in the lubricity and anti-adhesion of polymer brushes, and it is proposed to predict the anti-adhesion of polymer brushes by their lubricity to avoid costly and time-consuming bioassays during the development of amphoteric polymer brushes. A quantitative influence of hydration in the anti-adhesion properties of amphiphilic polymer brushes is also revealed. Thus, this study provides a new approach to safe, long-lasting lubrication and anticoagulant surface modification for medical devices in contact with blood.

Keywords: Zwitterionic polymer brush；High graft density；Stability；Anti-adhesion；Lubrication

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