Preparation and characterization of in situ chitosan/polyethylene glycol fumarate/thymol hydrogel as an effective wound dressing

Abstract In the present study, polyethylene glycol fumarate (PEGF) was synthesized as a component of blend solutions via polycondensation polymerization and characterized by different tests in order to determine its functional groups and its physical properties included melting and crystallization temperature, enthalpy of fusion and average molecular weights. Wound dressing films based on chitosan (Ch), PEGF and thymol (Th) were fabricated by solvent casting method with different formulations contained 80%(w/w) chitosan and 20%(w/w) PEGF as polymeric components and different amounts of thymol consisted of 0, 0.6, 1.2 and 1.8%(v/v) as pharmaceutical additives of blend solutions. These films were evaluated by different essential tests included Fourier transform infrared spectroscopy (FTIR), tensile testing, water vapor transmission rate (WVTR), water vapor uptake, equilibrium water uptake, water solubility, swelling, scanning electron microscopy (SEM) and antibacterial activity tests. The blend film contained 1.8%(v/v) thymol demonstrated optimal properties included acceptable mechanical properties, better absorption of water vapor or liquid water, higher water vapor transmission rate and air permeability, acceptable water solubility, superior swelling level, more porous structures and rough surfaces and the excellent antibacterial activity against both gram-negative and gram-positive bacteria which make it a suitable candidate for wound dressing applications.