Enhancement of Antibacterial and Hydrophilic Properties of <scp>LDPE</scp> Surfaces by Benzoxazine‐Chitosan Coatings: Structure and Performances

ABSTRACT Although low‐density polyethylene (LDPE) proved its efficacy in alleviating biliary obstruction stemming from biliopancreatic conditions as biliary stents, the problem of stent occlusion resulting from insufficient antibacterial and hydrophilic properties remains worth investigating. In this study, polydopamine (PDA) and poly(ethylene glycol) bis(carboxymethyl) ether (PEGb) were used as anchors on the LDPE surface, and then chitosan‐benzoxazine (CS x Bz y ) coatings were grafted with PEGb to obtain an innovative surface to enhance the antimicrobial and hydrophilic features of LDPE. The antimicrobial abilities of PE‐CS x Bz y were evaluated by co‐culture and plate coating techniques, demonstrating a remarkable inhibitory effect of up to 99.3% against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ). The field emission scanning electron microscopy (SEM) and the laser confocal scanning microscope further demonstrated that the PE‐CS x Bz y has excellent anti‐bacterial adhesion properties. Compared to pristine LDPE, the amount of adherent bovine serum albumin (BSA) and the number of bile proteins on the PE‐CS x Bz y surface were reduced by up to 64.56% and 80.26%, respectively. PE‐CS x Bz y exhibited excellent and stable hydrophilicity, with a water contact angle of approximately 50°, which only increased by 18.84% even after 30 days of immersion. PE‐CS x Bz y also showed complete biocompatibility with human biliary epithelial cells (BECs) and anticipation for biliary stent materials considering its exceptional hydrophilicity and antibacterial abilities. Moreover, the molecular dynamics simulations further demonstrated that the antibacterial properties and hydrophilic capabilities arise from the synergistic effect of chitosan‐benzoxazine coating structures. This study, we suggest, presents recommendations for regulating the antimicrobial and hydrophilic properties associated with LDPE materials utilized in biliary stent applications.