Multiple stimuli-responsive hydrogels for metal-based drug therapy

A series of homopolymeric and copolymeric hydrogels containing the N-isopropylacrylamide and vinyl monomers with α-amino acid (L-valine and L-phenylalanine) residues have been synthesized and their swelling properties were evaluated under different external stimulations. The hydrogels, obtained with different cross-linking agents (EBA and PEG-DA), have shown unique properties such as biocompatibility in addition to the stimuli-responsive characters. These ‘smart’ hydrogels exhibit single or multiple stimuli-responsiveness which could be used in biomedical applications, including controlled drug delivery. This article focuses on recent developments dealing with the delivery of metal-based drug (cisplatin, lithium) from the stimuli-responsive hydrogels proposed as platforms for cancer and bipolar disorder therapies.