Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John’s University, Queens NY, USA
Department of Physics, St. John’s College of Liberal Arts & Sciences, St. John’s University, Queens NY, USA
Abstract:
A polymeric magnetic nanoparticle system containing a brain permeability marker, fluorescein isothiocyanate dextran 4000 (FD4), was evaluated for brain targeting using in vivo brain microdialysis. Using FD4, oleic acid coated magnetic nanoparticles (OAMNP), copolymers, magnetic nanoparticles (NP) were prepared. Their morphology, particle size, ATR-FTIR spectra, maghemite content, fluorescent intensity, dye content and dye-release characteristics were evaluated. Biodistribution studies were performed on three groups of male Sprague Dawley rats (n = 5 in each group) with two groups serving as controls. A magnet (0.8 T) was placed on the head of the rats. The organs of the animals were analyzed for FD4 content. Brain microdialysis was performed in the ventral hippocampus of three groups of rats (n = 6). Samples were analyzed for fluorescence. The particle size of NP varied from 210 – 290 nm. The maximum dye loading obtained was 4.9% w/w. Confocal images showed uniform dye-distribution. In the biodistribution study, the brain-homogenates of the magnetically targeted group showed a significantly higher (p < 0.05) fluorescence than controls. Brain microdialysates of the magnetically targeted group showed fluorescence values of up to 100 ng/mL (corrected for probe recovery), as opposed to negligible fluorescence from controls. Nanoparticles under magnetic field displayed an enhanced the uptake of a brain permeability marker.