Influence of Process Variables on the Physical Properties of Gelatin/SA/HYA Composite Hydrogels

Abstract

A novel composite hydrogel based on gelatin, sodium alginate (SA) and hyaluronic acid (HYA) was fabricated by freeze-drying method using 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The effects of chemical cross-linking, including cross-linker content and cross-linking time, on the morphology, swelling ratio and compressive strength of the gelatin/SA/HYA hydrogel were investigated. The influence of pH value of the swelling medium on the swelling ratio of the gelatin/SA/HYA composite hydrogel was also studied. The results showed that the gelatin/SA/HYA composite hydrogel had a three-dimensional interconnected structure and the pore size decreased with increasing EDC concentration. The IR absorption peak intensity of the gelatin/SA/HYA hydrogel has no obvious variety with increasing EDC content. The swelling ratio of the gelatin/SA/HYA hydrogel decreased with increasing cross-linker content and cross-linking time; however, the compressive strength increased with increasing EDC content and cross-linking time. The hydrogel swelling peak reached at pH 7. Therefore, the architecture and the physical properties of the gelatin/SA/HYA composite hydrogel can be adjusted by controlling the chemical cross-linking conditions and pH value of swelling medium.