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

Abstract

There is an urgent need for the development of effective antibacterial coatings to cope with more and more resistant bacterial strains in medical environments, and particularly to prevent nosocomial infections following bone implant surgery. Polyelectrolyte multilayers (PEMs) based on poly‐l‐lysine (PLL) and complexes of poly(acrylic acid) (PAA) and gentamicin have been fabricated here applying the layer‐by‐layer (LbL) technique. Complexes are prepared by mixing PAA and gentamicin solutions in 500 × 10−3 m NaCl at pH 4.5. The assembly of PLL and the complexes follows an exponential growth allowing a high loading of gentamicin in a four bilayer PEM. Although PEMs are stable and do not degrade at physiological pH, there is a continuous release of gentamicin at pH 7.4. PEMs show an initial burst release of gentamicin in the first 6 h, which liberates 58% of the total gentamicin released during the experiment, followed by a sustainable release lasting over weeks. This release profile makes the coating appealing for the surface modification of bone implants as a high concentration of antibiotics is necessary during implant surgery while a lower antibiotic concentration is needed until tissue is regenerated. PEMs are effective in preventing the proliferation of the Staphylococcus aureus strain.

Nanofibrillar Hydrogels by Temperature Driven Self‐Assembly: New Structures for Cell Growth and Their Biological and Medical Implications

“…In future work, the developed here nanofibrillar structures can be functionalized by different essential functional components, for example, pectins, [ 88,89 ] chitosan, [ 90 ] gentamicin, [ 91 ] which can be used to regulate environment and antibacterial properties. [ 92,93 ] Alternatively, nanoparticle functionalization of the surfaces would enable remote release capabilities, [ 94 ] while functionalization with anisotropic structure would permit mechanical properties control.…”

<p>Macro-Microporous Surface with Sulfonic Acid Groups and Micro-Nano Structures of PEEK/Nano Magnesium Silicate Composite Exhibiting Antibacterial Activity and Inducing Cell Responses</p>

“…29 Implantable biomaterials with antibacterial performances can inhibit bacterial infection, and thus maintain long-term stability of the implants. 30 Previous studies have shown that -SO 3 H groups on biomaterials could reduce bacterial adhesion and prevent bacteria from biofilm formation, showing antibacterial performances. 31 In addition, sulfonation of PEEK caused a negatively charged surface, which produced a repulsive force between the negatively charged membranes of bacteria, thereby hindering bacteria attachment.…”

Antibacterial Layer-by-Layer Coatings for Medical Implants

“…The multilayer is formed on top of titanium discs, and they obtained an initial burst release of TC, which has an antibacterial effect against Porphyromonas gingivalis [ 100 ]. A. Escobar et al [ 101 ] prepared an antibacterial coating on titania based on the formation of complexes of PAA and gentamicin, which are assembled with poly lysine (PLL) ( Figure 3 A). The multilayer formation followed an exponential growth ( Figure 3 B) and was demonstrated to be effective in preventing the proliferation of S. aureus ( Figure 3 C) [ 101 ].…”

“…A. Escobar et al [ 101 ] prepared an antibacterial coating on titania based on the formation of complexes of PAA and gentamicin, which are assembled with poly lysine (PLL) ( Figure 3 A). The multilayer formation followed an exponential growth ( Figure 3 B) and was demonstrated to be effective in preventing the proliferation of S. aureus ( Figure 3 C) [ 101 ]. Only four layers of PAA-gentamicin complexes and PLL are needed to produce a film with a superior antibacterial performance as compared to that reported elsewhere [ 90 ] The release of gentamicin shows a two-step profile; an initial burst release followed by a prolonged release lasting more than a month.…”

“…CFU of the adhered bacteria on the PEM and glass with gentamicin. Reproduced with permission from [ 101 ], John Wiley and Sons, Inc, 2019.…”