Preparation And Properties Of Hyaluronic Acid-gelatin / Acrylamide Dual-network Hydrogels

Hydrogels have been widely used,but there are still many problems in their applications,such as toxicity,mechanical properties,viscosity.These problems will limit the further application of hydrogels,and still need us to explore.Hydrogels are more widely used in the medical field.However,up to now,most hydrogels have only a single characteristic,such as good biocompatibility but poor mechanical properties,strong mechanical properties but toxic.These also limit the application of hydrogels in medical field to some degree.In response to these problems,we have prepared a hydrogel with both good biocompatibility and mechanical properties,which broaden the application of hydrogels in medicine field.In this paper,the resultant hyaluronic acid-gelatin hydrogel possessed dual-network structure.The first network was formed by hyaluronic acid possessing good biocompatibility and water retention as well as gelatin with good biocompatibility under the initiation of ultraviolet light.Then the first network constituted by hyaluronic acid and gelatin was swollen in a solution containing acrylamide and crosslinking agent to reach the swelling equilibrium,which was irradiated by an ultraviolet lamp to form the second network of the hydrogels.Although the acrylamide monomer is toxic,polyacrylamide is not toxic and has good mechanical properties,so that the hyaluronic acid-gelatin / hydrogel possess both good biocompatibility and mechanical properties.The fourier transform infrared spectroscopy(ATR-FTIR)characterization,nuclear magnetic test,rheological testing,scanning electron microscopy(SEM)test,compression test,swelling test were carried on the hydrogels.We found that the compressive strength of hyaluronic acid-gelatin/polyacrylamide dual-network hydrogel was five times higher than that of hyaluronic acid-gelatin hydrogel.The rheological tests showed that the storage modulus(G ')and loss modulus(G ")of hyaluronic acid-gelatin/polyacrylamide dual-network hydrogels were 100 times higher than that of hyaluronic acid-gelatin hydrogels.In addition,the hyaluronic acid-gelatin hydrogel broke under lower compressive stress,but hyaluronic acid-gelatin/polyacrylamide dual-network hydrogels did not rupture at high compression.The comparison of these tests showed that the introduction of polyacrylamide had greatly improved the mechanical properties of hydrogels,and the effects of various factors on hyaluronic acid-gelatin/polyacrylamide hydrogels properties had been studied in detail by these tests.It is envisaged that this strategy will be an effective way to enhance the mechanical strength of hydrogels thereby broadening the application of hydrogel biomaterials.