Bioinspired super-hydrophilic zwitterionic polymer armor combats thrombosis and infection of vascular catheters

Thrombosis and infection are two major complications associated with central venous catheters(CVCs),which significantly contribute to morbidity and mortality.Antifouling coating strategies currently represent an efficient approach for addressing such complications.However,existing antifouling coatings have limitations in terms of both duration and effectiveness.Herein,we propose a durable zwitterionic polymer armor for catheters.This armor is realized by pre-coating with a robust phenol-polyamine film inspired by insect sclerotization,followed by grafting of poly-2-methacryloyloxyethyl phosphorylcholine(pMPC)via in-situ radical polymerization.The resulting pMPC coating armor exhibits super-hydrophilicity,thereby forming a highly hydrated shell that effectively prevents bacterial adhesion and inhibits the adsorption and activation of fibrinogen and platelets in vitro.In practical applications,the armored catheters significantly reduced inflammation and prevented biofilm formation in a rat subcutaneous infection model,as well as inhibited thrombus formation in a rabbit jugular vein model.Overall,our robust zwitterionic polymer coating presents a promising solution for reducing infections and thrombosis associated with vascular catheters.

TiO_2 thin film photocatalyst

It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.

Zwitterionic polymers-armored amyloid-like protein surface combats thrombosis and biofouling

Proteins,cells and bacteria adhering to the surface of medical devices can lead to thrombosis and infection,resulting in significant clinical mortality.Here,we report a zwitterionic polymers-armored amyloid-like protein surface engineering strategy we called as“armored-tank”strategy for dual functionalization of medical devices.The“armored-tank”strategy is realized by decoration of partially conformational transformed LZM(PCTL)assembly through oxidant-mediated process,followed by armoring with super-hydrophilic poly-2-methacryloyloxyethyl phosphorylcholine(pMPC).The outer armor of the“armored-tank”shows potent and durable zone defense against fibrinogen,platelet and bacteria adhesion,leading to long-term antithrombogenic properties over 14 days in vivo without anticoagulation.Additionally,the“fired”PCTL from“armored-tank”actively and effectively kills both Gram-positive and Gram-negative bacterial over 30 days as a supplement to the lacking bactericidal functions of passive outer armor.Overall,this“armored-tank”surface engineering strategy serves as a promising solution for preventing biofouling and thrombotic occlusion of medical devices.