Synthesis, self-assembly, and characterization of PEG-coated iron oxide nanoparticles as potential MRI contrast agent.

AIM: Investigated the self-assembly and characterization of novel antifouling polyethylene glycol (PEG)-coated iron oxide nanoparticles as nanoprobes for magnetic resonance imaging (MRI) contrast agent. METHOD: Monodisperse oleic acid-coated superparamagnetic iron oxide cores are synthesized by thermal decomposition of iron oleate. The self-assembly behavior between iron oxide cores and PEG-lipid conjugates in water and their characteristics are confirmed by transmission electron microscope, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. RESULT: Dynamic light scattering shows superparamagnetic iron oxide nanoparticles coated with PEG are stable in water for pH of 3-10 and ionic strengths up to 0.3 M NaCl, and are protein resistant in physiological conditions. Additionally, in vitro MRI study demonstrates the efficient magnetic resonance imaging contrast characteristics of the iron oxide nanoparticles. CONCLUSION: The result indicates that the novel antifouling PEG-coated superparamagnetic iron oxide nanoparticles could potentially be used in a wide range of applications such as biotechnology, MRI, and magnetic fluid hyperthermia.

Preparation, characterization, and biodistribution of breviscapine proliposomes in heart.

Breviscapine proliposomes were prepared by ethanol injection-homogenization-lyophilization method. On contact with 5% glucose, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of breviscapine was entrapped by the liposomes. The entrapment efficiency measured by reverse dialysis method was 77.89 +/- 0.28%. The particle size, polydispersity index, and zeta potential of breviscapine liposomes were 504.83 +/- 52.88 nm (by intensity), 0.17 +/- 0.02, and -(20.31 +/- 1.03) mV, respectively (mean +/- SD, n = 3). In mimic-biomembrane model experiment, breviscapine was distributed not only to n-octanol and buffer phase but also to interfacial phase. After bolus administration, the elimination phase (t(1/2(beta)) = 66.386) of liposomal formulation in plasma was 4.8 times longer than that of solution formulation (t(1/2(beta)) = 13.695). The AUC and MRT values of liposomal formulation in heart were increased more than 11.7- and 3.2-fold versus solution formulation, respectively. These results were all beneficial to heart disease therapy.