title: The characteristics, biodistribution, magnetic resonance imaging and biodegradability of superparamagnetic core-shell nanoparticles.
abstract: An efficient contrast agent for magnetic resonance imaging (MRI) is essential to enhance the detection and characterization of lesions within the body. In this study, we described the development of biodegradable nanoparticles with a core-shell structure to formulate superparamagnetic iron oxide (CSNP-SPIO) for MRI. The developed nanoparticles were composed of a hydrophobic PLGA core and a positively-charged glycol chitosan shell. The results obtained by transmission electron microscopy, energy dispersive X-ray analysis, electron energy loss spectroscopy, and X-ray diffraction measurement confirmed that the prepared nanoparticles had a core-shell structure with SPIO in their core area. No aggregation of nanoparticles was observed during storage in water, as a result of the electrostatic repulsion between the positively-charged nanoparticles. The magnetic properties of nanoparticles were examined by a vibrating sample magnetometer and a superconducting quantum interference device; the results showed that the superparamagnetism of SPIO was preserved after the CSNP-SPIO formulation. In tracking their cellular internalization pathway, we found that CSNP-SPIO accumulated in lysosomes. In the biodistribution study, a high level of radioactivity was observed in the liver shortly after administration of the (99m)Tc-labeled CSNP-SPIO intravenously. Once taken up by the liver cells, the liver turned dark on T(2)* images. Following cellular internalization, CSNP-SPIO were broken down gradually; therefore, with time increasing, a significant decrease in the darkness of the liver on T(2)* images was found. The aforementioned results indicate that the developed CSNP-SPIO can serve as an efficient MRI contrast agent and could be degraded after serving their imaging function.
authors: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, ROC.
authors: Po-Wei
authors: PW
authors: Lee
authors: Sheng-Hsiang
authors: SH
authors: Hsu
authors: Jiun-Jie
authors: JJ
authors: Wang
authors: Jin-Sheng
authors: JS
authors: Tsai
authors: Kun-Ju
authors: KJ
authors: Lin
authors: Shiaw-Pyng
authors: SP
authors: Wey
authors: Fu-Rong
authors: FR
authors: Chen
authors: Chih-Huang
authors: CH
authors: Lai
authors: Tzu-Chen
authors: TC
authors: Yen
authors: Hsing-Wen
authors: HW
authors: Sung
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry* / Q000493:pharmacokinetics*; D005290:Ferric Compounds / Q000737:chemistry / Q000493:pharmacokinetics*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; C000499:ferric oxide