title: Thermosensitive/magnetic poly(organophosphazene) hydrogel as a long-term magnetic resonance contrast platform.
abstract: 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 (CoFe(2)O(4)) 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.
authors: Biomaterials Center, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors: Jang Il
authors: JI
authors: Kim
authors: ChangJu
authors: C
authors: Chun
authors: Bora
authors: B
authors: Kim
authors: Ji Min
authors: JM
authors: Hong
authors: Jung-Kyo
authors: JK
authors: Cho
authors: Seung Hoon
authors: SH
authors: Lee
authors: Soo-Chang
authors: SC
authors: Song
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D041681:NIH 3T3 Cells; D009943:Organophosphorus Compounds / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D051381:Rats
chemical_list: D003287:Contrast Media; D009943:Organophosphorus Compounds; D011108:Polymers; C515246:poly(organophosphazene); D020136:Hydrogel, Polyethylene Glycol Dimethacrylate