Using Targeted Nano-Antibiotics to Improve Antibiotic Efficacy against Staphylococcus aureus Infections

Abstract

The poor bioavailability of antibiotics at infection sites is one of the leading causes of treatment failure and increased bacterial resistance. Therefore, developing novel, non-conventional antibiotic delivery strategies to deal with bacterial pathogens is essential. Here, we investigated the encapsulation of two fluoroquinolones, ciprofloxacin and levofloxacin, into polymer-based nano-carriers (nano-antibiotics), with the goal of increasing their local bioavailability at bacterial infection sites. The formulations were optimized to achieve maximal drug loading. The surfaces of nano-antibiotics were modified with anti-staphylococcal antibodies as ligand molecules to target S. aureus pathogens. The interaction of nano-antibiotics with the bacterial cells was investigated via fluorescent confocal microscopy. Conventional tests (MIC and MBC) were used to examine the antibacterial properties of nano-antibiotic formulations. Simultaneously, a bioluminescence assay model was employed, revealing the rapid and efficient assessment of the antibacterial potency of colloidal systems. In comparison to the free-form antibiotic, the targeted nano-antibiotic exhibited enhanced antimicrobial activity against both the planktonic and biofilm forms of S. aureus. Furthermore, our data suggested that the efficacy of a targeted nano-antibiotic treatment can be influenced by its antibiotic release profile.

Effect of poly (lactic-co-glycolic acid) polymer nanoparticles loaded with vancomycin against Staphylococcus aureus biofilm

“…However, after 72 h of incubation, the antimicrobial activity of synthesized nanodrugs increased due to the release of high mounts of the drug and became close to that of the free drug. This is because the drug release duration in our study was 72 h. In the study by Le et al [ 47 ] the MIC and MBC of Free-Lev were lower than that of PLGA-Lev on S. aureus strains, which they attributed to the incomplete drug release from PLGA. As mentioned, it took approximately 72 h for the drug to be released from PLGA.…”