Microwave assisted chitosan-polyethylene glycol hydrogel membrane synthesis of curcumin for open incision wound healing.

Chitosan and polyethylene glycol hydrogel membranes containing curcumin were synthesized using microwave technology at fixed frequency, power and time of 2450 MHz, 500 Watt and 120 s. Polymers were solubilized separately, combined with drug and mixed in two different ratios i.e. F1=80:20 and F2=85:15. The untreated and microwave treated hydrogel membranes were analyzed for degree of swelling, degree of degradation, tensile strength, surface morphology, vibrational and thermal analysis and in vitro drug release. Results indicated that F2(micro) showed a significantly high degree of swelling (96.49±1.21 %), low degradation (9.88±1.68 %), sustained drug release through slow erosion (55.1±3.11 %) via non-Fickian diffusion. The vibrational and thermal analysis revealed rigidification of hydrophilic domains of the polymers by formation of hydrogen bonds between chitosan and PEG moieties (OH/NH) and elasticity of hydrophobic domains (asymmetric and symmetric CH moieties and/or C=O moieties) which not only significantly increased the transition temperature and enthalpy (297.2±3.2 °C and 4.24±1.4 J/g) of the chitosan moiety but also resulted in enhanced tensile strength (18.2±1.3 Mpa). In vivo wound healing study revealed significantly faster wound healing in the F2(micro) treated animal group in comparison to a control animal group where at day 14, a significant re-epithelization (87.26 %) with smaller wound size was observed. Hence microwave assisted chitosan-PEG hydrogel membrane of curcumin is advocated to be a suitable plate form for wound healing applications.