Preparation and characterization of composite hydrogels based on crosslinked hyaluronic acid and sodium alginate

In this study, a novel composite hydrogel with improved cellular structure and mechanical properties was prepared by the crosslinking of hyaluronic acid (HA) and sodium alginate (SAL). The amide linkages (covalent bonds) in the hydrogel that we expected to form were confirmed by Fourier transform infrared spectroscopy. The hydrogels had a pore size larger than 100 μm and were observed by scanning electron microscopy. Texture profile analysis indicated that the hardness of the hydrogels was enhanced by an increase in the polymer's concentration, but it declined with an increase in the HA/SAL molar ratio. The swelling capacity was reduced with increases in the polymer's concentration and the 1‐ethyl‐3‐(3‐dimethyl aminopropyl)‐1‐carbodiimide hydrochloride (EDC)/HA molar ratio, and it was enhanced by an increase in the HA/SAL molar ratio. The resistance against hyaluronidase was negatively correlated with the proportion of HA in the hydrogels and positively correlated with the EDC/HA molar ratio. Given the improved physicochemical properties that we produced, these novel hydrogels may have the potential to be applied in tissue engineering scaffolding.