Stable and Self-healable LbL Coating with Antibiofilm Efficacy Based on Alkylated Polyethyleneimine Micelles
Biomaterial-associated infections caused by bacteria adhesion and subsequent biofilm formation on the surface of biomedical implants/devices are starving for effective solutions. Current antibacterial coatings are usually vulnerable, which would impair or even eliminate their bactericidal efficacy upon scratch or abrasion. Self-healable coatings that capable of repairing defects themselves are highly desired. In this work, the N-decyl polyethyleneimine (DPEI), a cationic amphiphilic polymer which is able to self-assemble into micelles in water to concentrate the density of cationic charge, has exhibited enhanced antibacterial activity towards Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Pseudomonas aeruginosa. A layer-by-layer (LbL) assembled coating was prepared using DPEI micelles and polyacrylic acid (PAA), which could reduce more than 90% bacterial adhesion and prevent the biofilm formation. In addition, the DPEI/PAA LbL assembled coating was able to keep stable even rinsing in the physiological saline up to three weeks, owing to a stronger interaction induced by higher charge. More importantly, this antibacterial DPEI/PAA LbL assembled coating can achieve self-healing quickly under wet condition after being scratched, preventing bacteria from adhering to damaged areas and forming biofilm. Better yet, this coating avoids the using of antibiotics, which is less likely to cause drug-resistance. In addition, this coating is also biocompatible with mammalian cells (C2C12 mouse myoblast). All these excellent properties endow promising prospects for the biomedical application of this self-healing DPEI/PAA LbL assembled coating.