Antibacterial and Biocompatible Iodine-Releasing Polycationic Coatings Synthesized by Solvent-Free Initiated Chemical Vapor Deposition

Abstract

Abstract Bacterial adhesion to surfaces of medical devices may cause medical device-associated infections. This challenge can be addressed by surface modification utilizing antibacterial coatings. Polycationic coatings possess excellent antibacterial activity, but their biocompatibility has always been a concern. Iodine (I) is a broad-spectrum antibacterial reagent against most pathogenic bacteria. Negatively charged iodine anions can be complexed with positively charged polycations due to electrostatic interaction. I3– can be released from the complex and converted to I2 to kill bacteria. Therefore, I3– can be complexed with polycations with relatively low positive charge density to enhance the antibacterial activity of polycationic coatings and improve their biocompatibility. Initiated chemical vapor deposition (iCVD) is a cutting-edge technique for synthesizing high-quality polymeric coatings under mild reaction conditions without solvents. In this study, cationic poly(dimethylaminomethylstyrene-co-ethylene glycol dimethacrylate) (PDE) coatings with a thickness of around 200 nm and different cross-linking degrees of 70.42% (PDE-1) and 35.59% (PDE-2) were firmly deposited on surfaces via iCVD, and subsequently complexed with I3– to produce PDE-I polycation-iodine coatings. These coatings exhibited potent antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. PDE-I-1 exhibited excellent biocompatibility in vitro and in vivo. The study provides a viable method to fabricate biocompatible and broad-spectrum antibacterial coatings for combating pathogenic infections on medical devices.