Antibiotic-loaded gelatin fibers fighting bacteria resistant to antibiotics: a case of spectinomycin-resistant Escherichia coli

Abstract

Infection with antibiotic-resistant bacteria can lead to higher mortality, morbidity, and healthcare costs. An open wound is highly susceptible to microbial infection. To encourage prompt healing, a wound requires a biomimetic dressing material, ideally with hydrophilic and antimicrobial properties. Herein, we propose hydrophobic, cargo-loaded gelatin fibers useable against antibiotic-resistant bacteria. Scanning electron microscopy (SEM) demonstrated the successful formation of the hydrophilic fibers and allowed us to characterize the morphology and the average fiber diameter before and after hydrophobic cargo loading. Differential scanning calorimetry (DSC) measurements indicated that the gelatin-based fibers may have undergone renaturation after electrospinning. Dynamic mechanical analysis (DMA) measurements showed that the presence of hydrophobic cargo enhanced the mechanical properties of the gelatin fibers without the necessity of a crosslinking step. The measurements were then repeated for the fiber when loaded with ciprofloxacin, a hydrophobic antibiotic. The in vitro antibacterial property of the designed ciprofloxacin-loaded gelatin fibers was evaluated by film-diffusion against spectinomycin-resistant Escherichia coli. An inhibitory effect on bacterial growth in a solid medium was observed. These findings demonstrated the potential of the designed fiber to be used as an antimicrobial material for the prevention and treatment of wound infections, particularly those resistant to antibiotic therapy.