Study On TAT Mediated Magnetic Microspheres Having Composite Targeting Funtion

Lysine Chemically modified chitoan with good water solubility was synthesized in this paper,and the coordination conditions(stirring rate,the reaction time,temperation,DMF/H2O)were optimized. The optimal swellen parameters were R= 1200 rpm,T=20℃,DMF/H2O=1,t= 6 h。Its composition and structure was characterized by FT-IR,1H-NMR and 13C-NMR, and the degree of substitution was 32.78% which was calculated by 1H-NMR.Then the lysine modified chitosan was used as matrix to prepare magnetic microspheres using co-precipitation method.The microspheres were analysised by XPS,TEM,XRD, VSM and Zeta Potential Analyzer. The results showed that the particles were spherical and uniform in dimension with particle diametrers of 100nm ,and had good supermagnetic characterization ,they also had many positive charge on their surface.We coupled TAT and folate on the surface of lysine modified chitosan magnetic micropheres to form TAT mediated magnetic nanoparticles having composite targeting function.And all of the components of the TAT-FA-LCMNPs was quantitively investigated by UV respectively .Additionally, combination of DNA and four kinds of MNPs was observed from agarose gel electrophoresis, suggesting that the LCMNPs could be a novel kind of magnetic targeting gene carriers. The biodistribution and the ability for crossing BBB of 99Tc-labeled MNPs and DNA complexes were further investigated by single photon emission computed tomography (SPECT). The results showed TAT-FA-LCMNPs and DNA complexes successfully passed the blood-brain barrier under the magnetic field for 30min after being injected through the carotid...