Multiple response behaviors of curcumin-loaded ammonium alginate/polyvinyl alcohol hydrogel and its application

Safety, non-toxic, and degradable ammonium alginate with polyvinyl alcohol were selected as substrates for the preparation of AA/PVA hydrogel by simple co-blending and cyclic freeze-thaw methods. Curcumin as the model drug was encapsulated to obtain AA/PVA/Cur hydrogel. The resulting hydrogels were characterized using various techniques to confirm the success of preparation, including FTIR, SEM, XRD, TGA, and rheometer. In addition, multiple stimuli-responsive behaviors of hydrogels were studied in depth. For one thing, AA/PVA hydrogel showed dual response shape memory properties which could be fixed in a temporary shape in Ca2+ or low temperature and followed recovery to the original shape with more than 90% recovery rate in Na+ (Na2CO3 and EDTA.2Na) or high temperature respectively, confirming that the hydrogels have ion- and temperature-responsive behaviors. For another, the drug-loaded hydrogel AA/PVA/Cur exhibited different drug release properties under different pH stimulation conditions, where curcumin could reach nearly 90% release under alkaline conditions after 6 h, whereas the release rate was only nearly 20% under acidic conditions. AA/PVA/Cur hydrogel had antibacterial and antioxidant effects, especially under alkaline conditions. Thereinto, the antibacterial rate of Escherichia coli and Staphylococcus aureus reached over 90%, respectively. Among the four antioxidant systems, up to 98.5%, ABTS radical scavenging rate was prominent. In conclusion, multiple stimulus-response properties of AA/PVA hydrogel exhibit a unique three-dimensional network structure capable of drug loading, combined with various properties such as good hydrophilicity, biocompatibility, biodegradability, non-cytotoxicity, and hemocompatibility, which have potential applications in medical and pharmaceutical fields.