Layer-by-layer dip coating of Foley urinary catheters by chlorhexidine-loaded micelles

Abstract

Chlorhexidine-loaded poly(ethylene glycol)-block-poly(ε-caprolactone) micelles (CHX-micelles) were prepared by the solvent evaporation method and were used to coat urinary catheters. The layer-by-layer (LbL) dip coating technique was used to coat the micelles onto the catheters, which consisted of the alternation of coating with CHX-micelles and poly(acrylic acid). The number of LbL nanocoating cycles was varied, and the properties of the coated catheters were investigated for their drug content and the coating thickness. The optimal coated catheter had 90 bilayers, which provided the maximum CHX content at 32.3 ± 1.4 μg/cm2, and the thickness of the thin film on these coated catheters was 6.87 ± 0.36 μm. Coated catheters were studied in the in vitro CHX-release, antibacterial activity, cytotoxicity, and hemolytic activity. Drug release from the coated catheters was controlled, and bacteria proliferation was inhibited for up to 6 days. Results suggest that the antimicrobial activity of the coated catheter reduces the adherence of uropathogens to the catheter's surface. The cytotoxicity and hemolytic activity of the coated catheters showed biocompatible properties. The coated catheter presented the potential to inhibit uropathogen colonization and formation. This nanocoating technology can also be applied to other medical implants that carry the risk of infection.