Novel Nanoparticle Theranostics for Anti-Oxidative Stress

摘要

Utilizing the self-assembled core-shell-type polymeric micelle technique, high-performance nanoparticles possessing stable nitroxyl radicals in the core and reactive groups on the periphery were prepared (Radical-containing nanoparticles; RNP). The cumulant average diameter of the nanoparticles was ca. 40 nm, and the nanoparticles emitted intense electron paramagnetic resonance (EPR) signals. The TEMPO radicals in the core of the nanoparticles showed reduction resistance even in the presence of 3.5 mM ascorbic acid. The EPR signal in blood stream of mice was observed even 2h after tail vein injection. It is sharp contrast against low molecular weight TEMPOL, which was reduced within 2 min in blood stream. The RNP thus prepared was found to be effective for brain injury by cerebral ischemia via anti-oxidative stress damage. The RNP is thus promising as high-performance nanoparticle theranostics, which can be used in vivo.