Loading of Antibiotics into Polyelectrolyte Multilayers after Self-Assembly and Tunable Release by Catechol Reaction

Abstract

The colonization of bacteria on biomedical implants and subsequent forming of biofilm often leads to serious infections. In this work, poly(acrylic acid) modified by dopamine (PAA-dopa) and poly(ethylenimine) (PEI) self-assembled into multilayer films were used to load and for sustained release of antibiotics. The obtained multilayer films were immersed in tris-buffered saline containing gentamicin sulfate (GS) to load the antibiotics and were cross-linked via catechol chemistry of dopa. Through raising pH value, more carboxyl groups of PAA were protonated and combined with GS through electrostatic forces. After cross-linking, the multilayer films were used as a drug delivery system to embed GS in the matrices which showed a two-stage sustained release profile. In vitro, the release of GS into phosphate-buffered saline (PBS) from the multilayer films, as well as the antibacterial activity, was determined. The drug-loaded multilayer films showed excellent bactericidal function against Staphylococcus aureus...