Redox-Responsive Hydrogels Loaded with an Antibacterial Peptide as Controlled Drug Delivery for Healing Infectious Wounds

Infectious wounds occur when harmful microorganisms such as bacteria or viruses invade a wound site. Its problems associated include delayed healing, increased pain, swelling, and the potential for systemic infections. Therefore, developing new wound dressing materials with antibacterial effects is crucial for improving the healing process. Here we developed a redox-degradable hydrogel loaded with an antibacterial peptide (vancomycin) in a straightforward gram-scale synthesis. The hydrogel structure consists of a disulfide bond-containing hyperbranched polyglycerol (SS-hPG) which is cross-linked by 4-arm polyethylene glycol-thiol (4-arm PEG-SH). The polymerization mechanism and full characterization of SS-hPG are described as we report this synthesis for the first time. The controlled release of antibacterial peptide follows, as the hydrogel degrades in a reductive environment triggered by glutathione. We used rheology to ascertain the hydrogel’s mechanical characteristics, such as stiffness, and self-healing, determining these properties for different ratios and concentrations of both blocks. Fluorescein isothiocyanate-albumin (FITC-albumin) and vancomycin were both loaded into the gel, and the guest release kinetics were assessed for both slow and ondemand releases. Finally, our in-vitro and in-vivo experiments proved that the vancomycin-loaded hydrogel acts as an antibacterial barrier for wound dressing and accelerates the healing of infectious wounds in a mouse model.