Copolymer Brushes with Temperature-Triggered, Reversibly Switchable Bactericidal and Antifouling Properties for Biomaterial Surfaces

Abstract

The adherence of bacteria and the formation of biofilm on implants is a serious problem that often leads to implant failure. A series of antimicrobial coatings have been constructed to resist bacterial adherence or to kill bacteria through contact with or release of antibacterial agents. The accumulation of dead bacteria facilitates further bacterial contamination and biofilm development. Herein, we have designed and constructed a novel, reversibly switchable bactericidal and antifouling surface through surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization to combine thermally responsive N-isopropylacrylamide (NIPAAm) and bactericidal quaternary ammonium salts (2-(dimethylamino)-ethyl methacrylate (DMAEMA)). Measurements of spectroscopic ellipsometry and water contact angle and X-ray photoelectron spectroscopy were used to examine the process of the surface functionalization. The temperature-responsive P(DMAEMA-co-NIPAAm) copolymer coating can switch by phase transition between a hydrophobic capturing surface at high temperatures and a relatively hydrophilic antifouling surface at lower temperatures. The quaternary ammonium salts of PDMAEMA displayed bactericidal efficiency against both Escherichia coli and Staphylococcus aureus. The functionalized surface could efficiently prevent bovine serum albumin adsorption and had good biocompatibility against human lens epithelial cells.

Upper critical solution temperature thermo-responsive polymer brushes and a mechanism for controlled cell attachment

“…1-5 Many of the reported polymer brushes so far have been developed for use as antifouling surfaces, due to the ability to tune polymer chemistry to resist short-term protein adsorption and subsequent cell adhesion. [6][7][8][9] Thermo-responsive polymer brushes have been considered as functional substrate modifiers as their surface wettability can be easily adjusted by changing temperature, enabling application in controlled cell adhesion and detachment. 10,11 The most widely studied thermoresponsive polymer is poly(N-isopropylacrylamide) (PNiPAm), which exhibits a lower critical solution temperature (LCST) phase transition in water at 32 ⁰C.…”

Mussel‐Inspired, Surface‐Attachable Initiator for Grafting of Antimicrobial and Antifouling Hydrogels

“…All surfaces exhibited almost no or less than 3% hemolysis after incubation with red blood cells for 1 h (Figure S5, Supporting Information), revealing the non‐hemolytic activity of these coatings. Furthermore, it is critical to assess the interaction between the implanted materials and their surrounding tissue, especially cell viability, to determine the ultimate functionality of the implants . In this study, the in vitro cytotoxicity of the MPHMG 10 ‐ co ‐PEG 10 coating was investigated with the Alamar Blue and LIVE/DEAD cell viability assay toward bone mesenchymal stem cells (BMSCs) ( Figure ).…”

Radical Cation Initiated Surface Polymerization on Photothermal Rubber for Smart Antifouling Coatings

“…The polymer is hydrophilic below its low critical solution temperature (LCST) and hydrophobic above the LCST, which is usually at 32 °C. Recently, great attention has been paid to the “killing and releasing” strategy –. This strategy refers to the cases in which bacteria are killed once attached to the bactericidal surface, and the dead bacteria are released when the surface is switched to antifouling surface.…”

“…This strategy refers to the cases in which bacteria are killed once attached to the bactericidal surface, and the dead bacteria are released when the surface is switched to antifouling surface. Classical synthetic methods, such as surface‐initiated atom‐transfer radical polymerization (SI‐ATRP) or surface‐initiated reversible addition–fragmentation chain‐transfer polymerization (SI‐RAFT), are complicated, rigorous, or require the use of special catalysts with potential toxicity issues. Although some air‐tolerant polymerization systems have been recently developed and improved this condition to some extent, it is still challenging to extend these methods to modify large surfaces .…”