Sustained antibacterial activity of chlorhexidine loaded-chitosan membrane via glutaraldehyde vapor crosslinking for periodontitis treatment

Periodontitis is a chronic inflammatory disease of the periodontal tissue that requires localized, sustained antimicrobial delivery to inhibit bacterial recolonization. Chitosan-based membranes are attractive candidates for local drug delivery due to their biocompatibility. However, their limited stability and uncontrolled drug release restrict long-term therapeutic use. In this study, a chlorhexidine (CHX)-loaded chitosan membrane was crosslinked using glutaraldehyde (GA) vapor to enhance stability and performance. The effects of GA concentrations (0%, 0.5%, 1.0%, and 1.5%) were evaluated using SEM, FTIR, and DSC. While SEM indicated no substantial morphological alterations, FTIR confirmed successful crosslinking through Schiff base (C N) formation, and DSC demonstrated reduced moisture loss with slight thermal stabilization at 0.5% GA. GA crosslinking increased rigidity, significantly reduced swelling (from ∼1300% to ∼300%), and slowed degradation, extending membrane stability beyond 10 days. Sustained CHX release (6.5–7.0 mg/100 mL by day 10) was maintained above the minimum inhibitory concentration. Antibacterial testing showed consistent inhibition zones (>20 mm) for 12 days in crosslinked samples, indicating prolonged antibacterial activity. These findings demonstrate that GA vapor crosslinking effectively enhances structural stability and controlled CHX release, supporting its potential as a localized therapeutic membrane for adjunctive periodontitis treatment.