Antibacterial PEG-Chitosan Hydrogels for Controlled Antibiotic/Protein Delivery

Bacterial infections impede the wound-healing process, leading to complications such as chronic wounds and ulcerations. Wound dressings have been used in wound management because of the ease of application, ability to cover irregular wound surfaces, and antibacterial characteristics. For efficient wound management, the dressings must also provide the release of growth factors to aid the tissue regeneration process. Injectable PEG-chitosan hydrogels have been developed for the controlled delivery of ciprofloxacin, an antibiotic, and BSA (decoy for macromolecular growth factors) to prevent infections as well as accelerate the healing process. Hydrogels were fabricated by cross-linking chitosan (0.5% w/v) with bifunctional PEG glyoxylic aldehyde (3, 6, 9, and 12% w/v) and characterized for their cross-linking, surface morphology, viscoelastic, injectability, self-healing, and swelling and degradation characteristics. On loading with ciprofloxacin or BSA, hydrogels provided the sustained release of ciprofloxacin for up to 24 h (≥80%) and that of protein for up to 120 h (≥90%). Ciprofloxacin-loaded hydrogels displayed efficient activities (≥80%) against E. coli and the antibacterial activities were sustained for up to 12 h. The live/dead cell assay showed that the loaded hydrogels are bactericidal, and MTT assay (≥80% cells viable) and cell encapsulation studies showed that hydrogels are nontoxic and cytocompatible toward mammalian cells (NIH-3T3). PEG-chitosan hydrogels may find use as injectable device for the controlled antibiotic and growth factor delivery in antibacterial applications.