Kinetic studies of gentamicin sulfate release from chitosan aerogels for wound dressings

This study reports for the first time the use of chitosan aerogels loaded with gentamicin sulfate as a model drug for biphasic release in wound dressings. Bacterial infections represent one of the main complications following injuries or burns, accounting for 75% of the mortality associated with such conditions. For this reason, the fundamental purpose of dressing is to restore the necessary environment for the healing of the injury. In this study, chitosan aerogels with gentamicin sulfate were developed using the lyophilization technique, incorporating antibiotic concentrations between 0.65 and 1.50 mg/ml. The dressings obtained showed an absorption capacity of 83%–92% of the exudate simulation buffer, which shows their swelling and liquid retention capacity. The drug release profiles showed a biphasic pattern, a rapid initial release, followed by a sustained phase, reaching between 70% and 80% release in 60 min. In vitro antimicrobial assays confirmed the efficacy of the dressings in inhibiting the growth of Staphylococcus aureus and Pseudomonas aeruginosa, with greater effectiveness at higher concentrations of the antibiotic (inhibition zone diameters up to ≈43 mm for S. aureus). Therefore, the developed dressing combines structural properties, fluid absorption, controlled release of a model molecule, and antimicrobial protection, presenting a promising option for wound treatment.