Preparation and evaluation of chitosan-pectin hydrogel films incorporated with Aloe vera-mediated ZnO (AV-ZnO) for diabetic wound healing

Abstract: Background: Diabetic wounds are challenging due to delayed healing, inflammation, oxidative stress and bacterial infections, which conventional dressings often inadequately address. Objectives: To develop and characterize Aloe vera-mediated ZnO-loaded chitosan-pectin composite hydrogel films and evaluate their physicochemical, antibacterial, antioxidant, and in-vivo wound-healing efficacy in streptozotocin-induced diabetic male Wistar rat. Methods: AV-ZnO was synthesized using Aloe vera gel extract and incorporated into CS/PT hydrogels via solution casting to formulate three groups: PC (without AV-ZnO), PCG-1 (10 mg AV-ZnO), and PCG-2 (20 mg AV-ZnO). Physicochemical characterization included FTIR, SEM, AFM, TGA, gel fraction, contact angle, and tensile testing. Antibacterial activity was assessed against Staphylococcus aureus and Escherichia coli via disk diffusion, and antioxidant activity via DPPH radical-scavenging assay. In-vivo wound-healing efficacy was evaluated in streptozotocin-induced diabetic male Wistar rats (N = 24, n = 6/group) across four groups: untreated control, gentamicin-treated control, topical PCG-2, and exploratory oral PCG-2 hydrogel. Results: AV-ZnO incorporation improved tensile strength (10.1 MPa for PCG-2), hydrophilicity, gel fraction, and thermal stability. PCG-2 exhibited the strongest antibacterial activity, with inhibition zones of 28 mm against S. aureus and 20 mm against E. coli, attributed to AV-ZnO (Zn²⁺ release kinetics not evaluated). Antioxidant activity rose concentration-dependently, with PCG-2 showing 60.33% radical scavenging at 0.6 mg/mL. In-vivo, topical PCG-2 showed the highest wound contraction (89.09% ± 0.61 %, p < 0.05 vs. control) by day 15, surpassing exploratory oral treatment (72.84% ± 0.65%) and gentamicin (topical treated group) (83.77% ± 0.25%). Histology indicate improved re-epithelialization and collagen organization with topical treatment versus controls.