Hyperthermia evaluation and drug/protein-controlled release using alternating magnetic field stimuli-responsive Mn-Zn ferrite composite particles.

Drug delivery particles in which the release of biomolecules is triggered by a magnetic simulant have attracted much attention and may have great potential in the fields of cancer therapy and tissue regenerative medicine. In this study, we have prepared magnetic Mn-Zn ferrite ((Mn,Zn)Fe 2 O 4 ) (MZF) nanoparticles coated with chitosan- g-N -isopropylacrylamide (Chi- g -NIPAAm) polymer (MZF@Chi- g -NIPAAm) to deliver the anticancer drug (Doxorubicin, DOX) and bioactive proteins (Bone morphogenic protein (BMP-2)-immobilized bovine serum albumin (BSA)) (P//MZF@Chi- g -NIPAAm) and be used as chemo-hyperthermia and vector delivering biomolecules. For these purposes, we first show that the as-prepared MZF@Chi- g -NIPAAm particles exhibit super paramagnetic behavior and under certain conditions, they can act as a heat source with a specific absorption rate (SAR) of 34.88 W g -1 . Under acidic conditions and in the presence of AMF, the fast release of DOX was seen at around 58.9% within 20 min. In vitro evaluations indicated that concurrent thermo-chemotherapy treatment by DOX-MZF@Chi- g -NIPAAm using AMF had a better antitumor effect, compared with those using either DOX or DOX-MZF@Chi- g -NIPAAm without AMF (89.02% of cells were killed as compared to 71.82% without AMF exposure). Up to 28.18% of the BSA (used as the model protein to determine the controlled release) is released from the P//MZF@Chi- g -NIPAAm particles under AMF exposure for 1 h (only 17.31% was released without AMF). These results indicated that MZF@Chi- g -NIPAAm particles could be used to achieve hyperthermia at a precise location, effectively enhancing the chemotherapy treatments, and have a promising future as drug or bioactive delivering molecules for cancer treatment and cartilage or bone regenerative applications.