EFFECTS OF CHEMICAL COMPOSITIONS OF CHITOSAN-BASED HYDROGEL ON PROPERTIES AND COLLAGEN RELEASE

Chitosan-based hydrogels have drawn attention from a wide range of applications including drug delivery, heavy metal removal, and wound dressing. This is due to its biocompatibility, biodegradability, and responsiveness. Physical crosslinking is an easy and eco-friendly way to form hydrogels and the degree of crosslinking influences their mechanical and mass-transport properties. In this research, polyvinyl alcohol (PVA) was used as a co-hydrogel base polymer along with chitosan, where it was found that an increase in the PVA content by 1% w/v improved the tensile strength of the hydrogel film by 75%. An increase in glycerol which is a plasticizer increased hydrogel elasticity but lowered the tensile strength of the film. When the surfactant, Polysorbate80 (PS80), was added at a concentration of 0.5% w/v, the tensile strength improved between 70-150%. The hydrogel film with a high degree of crosslinking possessed good mechanical properties; however, contained less amounts of voids resulting in less water absorption. The results illustrated that percent swelling as high as 650% could be obtained. Surprisingly, although the percent swelling varied according to the mechanical properties of the films, the absorption of collagen solution was indistinguishable and remained at 30% absorption for all the film compositions studied. Nevertheless, collagen release correlated with the mechanical properties and percent swelling of the hydrogel films, where high percent swelling films released collagen faster. As they are physically incorporated, there are weak interactions between collagen and hydrogels, resulting in considerably fast collagen release which was completed within 5-6 hrs.