Fabrication of magnetic core/shell hydrogels via microfluidics for controlled drug delivery

Magnetic thermosensitive hydrogels stand out in the field of magnetic hyperthermia because of theirdual responses of both magnetic and thermal stimulations. In this work, the microfluidic technologywas utilized to prepare magnetic thermosensitive hydrogels. Two anticancer drugs, camptothecin anddoxorubicin hydrochloride, were loaded in the core and shell layers of generated double emulsions toachieve the simultaneous delivery of hydrophobic and hydrophilic drugs. The targeted delivery of com-posite drugs could be achieved by embedding Fe3O4 nanoparticles in the shell layer of double emulsions. In addition, under the effect of a high frequency alternating magnetic field, the thermal effect of magneticnanoparticles caused by the loss processes during the reorientation of the magnetization would increasethe temperature of hydrogel and change its swelling state, thus achieving sustained and controlledrelease of encapsulated drugs. Alternatively, the heat generated by magnetic nanoparticles under a highfrequency alternating magnetic field could locally heat up the tissue, thus realizing hyperthermia. Theresults of cellular cytotoxicity assay indicated that these combined drug loaded hydrogels provided suf-ficient cytotoxicity in the cancer cell inhibition, and it was also demonstrated that poly (N-isopropyl acry-lamide) (PNIPAM) could be used as a safe carrier for drug delivery systems. (C) 2021 Published by Elsevier Ltd.