Preparation of hydrogel containing chitosan and virgin coconut oil using the freeze-thawing method

Abstract

This study aimed to formulate a hydrogel membrane containing chitosan (CS) and virgin coconut oil (VCO) using repeated cycles of freezing and thawing (F-T) for wound dressing applications. This study evaluated the effects of degree of hydrolysis of polyvinyl alcohol (PVA), solution concentration and thickness, number of F-T cycles, CS proportion on the sensory properties, swelling ratio, and gel fraction of hydrogels. The antibacterial ability of PVA/CS/VCO membrane against methicillin sensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans was evaluated by disk diffusion method. The results showed that PVA with a high degree of hydrolysis (over 99%) easily generated hydrogel after several F-T cycles. The thicker the hydrogel membrane or the higher the concentration of PVA solution was, the lower the flexibility, elasticity, swelling ratio was, and the higher the gel fraction was. The formula including 10% PVA solution, the ratio of CS to PVA is 40%, 5% w/w VCO, through 3 F-T cycles created hydrogel with suitable properties and good antibacterial activity.