Redox-responsive degradable microgel modified with superparamagnetic nanoparticles exhibiting controlled, hyperthermia-enhanced drug release

Abstract A novel degradable microgel based on poly( N -isopropylacrylamide) (pNIPA) cross-linked with , ’-bisacryloylcystine (BISS) and containing superparamagnetic iron oxide nanoparticles (SPION@CA) was synthesized by semi-batch precipitation polymerization examined as a potential hyperthermia-enhanced drug carrier. The pNIPA provided the temperature sensitivity, BISS responsible for degradation in presence of glutathione (GSH) (an –S–S–bond reductor naturally present cells), while SPION@CA permitted remote control to improve release. microgels exhibited volume phase transition at ca. 34 °C, which is near human body temperature, were stable across wide range temperatures ionic strengths, well blood plasma 37 °C. It found that polymer network enabled be increased up 42 °C an alternating magnetic field, increasing from significantly enhanced releasing anticancer doxorubicin (DOX). highest DOX release (82%) observed pH 5, GSH, lowest (20%) 7.4, absence GSH. MTT assay indicated compared free doxorubicin, particles loaded have comparable cytotoxicity against MCF-7 cancer cells being less toxic MCF-10A healthy cells. Graphical abstract