Antibacterial Layer‐by‐Layer Films of Poly(acrylic acid)–Gentamicin Complexes with a Combined Burst and Sustainable Release of Gentamicin

ESCOBAR, ANE; LIBERTONE, SARA; GRZELCZAK, MAREK; MUZZIO, NICOLÁS E.; TASCA, ELISAMARIA; MOYA, SERGIO E.; ANDREOZZI, PATRIZIA; AZZARONI, OMAR

Advanced Materials Interfaces

VCH-Wiley

Año: 2019 vol. 6

2196-7350

There is an urgent need for the development of effective antibacterialcoatings to cope with more and more resistant bacterial strains in medicalenvironments, and particularly to prevent nosocomial infections followingbone implant surgery. Polyelectrolyte multilayers (PEMs) based on poly-llysine(PLL) and complexes of poly(acrylic acid) (PAA) and gentamicin havebeen fabricated here applying the layer-by-layer (LbL) technique. Complexesare prepared by mixing PAA and gentamicin solutions in 500 × 10−3 m NaClat pH 4.5. The assembly of PLL and the complexes follows an exponentialgrowth allowing a high loading of gentamicin in a four bilayer PEM.Although PEMs are stable and do not degrade at physiological pH, thereis a continuous release of gentamicin at pH 7.4. PEMs show an initialburst release of gentamicin in the first 6 h, which liberates 58% of the totalgentamicin released during the experiment, followed by a sustainable releaselasting over weeks. This release profile makes the coating appealing for thesurface modification of bone implants as a high concentration of antibioticsis necessary during implant surgery while a lower antibiotic concentrationis needed until tissue is regenerated. PEMs are effective in preventing theproliferation of the Staphylococcus aureus strain.