Novel temperature and pH dual-sensitive PNIPAM/CMCS/MWCNT semi-IPN nanohybrid hydrogels: Synthesis, characterization, and DOX drug release

Novel poly(N-isopropylacrylamide)/carboxymethyl chitosan/multiwalled carbon nanotube semi-interpenetrating nanohybrid hydrogels were prepared, and the chemical structure and morphology were characterized. The prepared hydrogels showed temperature and pH dual-responsiveness, and the one containing multiwalled carbon nanotubes (MWCNTs)–COOH possessed high maximal swelling ratios. The phase transition produced at pH of 6.8–7.4 and temperature of 35–40°C, hinging on the system compositions and charge ratios. The hydrogels were used to load hydrophilic anticancer drug, with high entrapped efficiency of about 44%. The drug release changed with temperature, pH, and MWCNTs–COOH contents. The designed hydrogels can be used for site-specific target delivery of protein or hydrophilic anticancer drug.