Novel Temperature and pH Dual Sensitive PNIPAM/CMCS/MWCNTs semi-IPN Nanohybrid Hydrogels: Synthesis, Characterization and DOX Drug Release

Novel poly(N-isopropylacrylamide)/carboxymethyl chitosan/multiwalled carbon nanotubes 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 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.