Reversible multistimuli-responsive manganese–zinc ferrite/P(NIPAAM-AAc-AAm) core-shell nanoparticles: A programmed ferrogel system

Abstract Intelligent ferrogels (consist of a functional hydrogel incorporating magnetic nanoparticles (NPs)) have attracted extensive attention due to their special properties, making them promising for biomedical applications. Controlled drug delivery systems alongside magnetic fluid hyperthermia are the most important applications of these ferrogels. In present work, manganese-zinc ferrite NPs were synthesized by thermal decomposition method. Hydrogel were produced with different percetage of acrylic acid and acrylamide. The NPs were coated with the optimized thermoresponsive copolymer N-isopropylacrylamide co-acrylic acid co acrylamide P(NIPAAm-4%AAc-8%AAm) by mini-emulsion method. Doxorubicin (DOX) was loaded into the ferrogel and the drug release profiles were plotted in different temperatures. Specific absorption rate (SAR) value was used to evaluate the hyperthermal efficiency of the ferrogel. The results showed that the synthesized NPs were single phase spinel with narrow size distribution. The average NPs size was reported about 10 nm. The Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy analyses confirmed the accurate formation of the copolymer. Ultraviolet–visible (UV–visible) spectrophotometry results illustrated that the lower critical solution temperature (LCST) of the hydrogel was increased from 32.5 to 39.2 °C, because of copolymerizing the NIPAAm monomer with hydrophilic monomers (AAm and AAc). The drug release study of the ferrogel samples in different temperatures showed that the drug release profile was significantly increased above LCST, because of the dehydration of thermo-responsive copolymer chains.