Kim, Jang Il Chun, ChangJu Kim, Bora Hong, Ji Min Cho, Jung-Kyo Lee, Seung Hoon Song, Soo-Chang 2024-01-20T15:34:20Z 2024-01-20T15:34:20Z 2021-09-04 2012-01 0142-9612 https://pubs.kist.re.kr/handle/201004/129692 A thermosensitive/magnetic poly(organophosphazene) hydrogel (a magnetic hydrogel) was designed and synthesized for long-term magnetic resonance (MR) imaging. To turn a thermosensitive poly(organophosphazene) hydrogel (an original hydrogel) into a long-term MR contrast platform, cobalt ferrite (CoFe2O4) nanoparticles, which have hydrophobic surfaces, were bound to the original hydrogel via interactions between the hydrophobic surfaces of the nanoparticles and the L-isoleucine ethyl esters of the polymer. The magnetic hydrogel showed extremely low cytotoxicity and adequate magnetic properties for use in long-term MR imaging, in addition to possessing the same properties of the original hydrogel, such as viscosity, thermosensitivity, biodegradability, biocompatibility, a reversible sol-to-gel phase transition near body temperature, and injectability. The magnetic hydrogel was injected into a rat brain using stereotactic surgery. After the injection, the applicable potentiality as a long-term MR contrast platform was successfully estimated over 4-5 weeks. Consequently, it was shown that a magnetic hydrogel as a long-term MR contrast platform has the potential to be applied in a long-term theranostic hydrogel system. Furthermore, it is expected that this platform can be useful in the clinical field of incurable diseases due to either surgical difficulties or lethality, such as with brain tumors, when the platform is combined with therapeutic drugs for long-term MR theragnosis in further studies. (C) 2011 Elsevier Ltd. All rights reserved. English ELSEVIER SCI LTD SUPERPARAMAGNETIC IRON-OXIDE CONTROLLED-RELEASE CANCER DRUG ANGIOGRAPHY FERROGELS RISKS Thermosensitive/magnetic poly(organophosphazene) hydrogel as a long-term magnetic resonance contrast platform Article 10.1016/j.biomaterials.2011.09.033 1 BIOMATERIALS, v.33, no.1, pp.218 - 224 BIOMATERIALS 33 1 218 224 scie scopus 000297399700022 2-s2.0-82855172106 Engineering, Biomedical Materials Science, Biomaterials Engineering Materials Science Article SUPERPARAMAGNETIC IRON-OXIDE CONTROLLED-RELEASE CANCER DRUG ANGIOGRAPHY FERROGELS RISKS Phosphazene Magnetic hydrogel Contrast agents MRI Hydrophobic interaction Long-term MR imaging