The Nanoparticle-Quantum Dots Distribution In The Olfactory Bulb Of Mice After Nasal Inhalation

OBJECTIVE:1.The study of the article is to inspect if the nanoparticle―quantum dots distribution in the olfactory bulb and central nervous system of mice after nasal inhalation and extrap the possible mechanism,what can offer straight optic model for other nanoparticle distribution in the olfactory bulb and central nervous system;at the same time can develop nanometer nasal cavity medicine targeting vector and open up a new pathway for screening the nasal administration active drug. 2. The study of the article is to inspect the stability of quantum dots in the physiological condition and in the need solution which was used in the tissue slice,what can choose the suitable tissue slice solution and considerate the confusing ability of withstanding external factor.METHODS: The study of the article had analogued the nanoparticle exposure state in the environment and the mode of nasal administration. Giving the nanoparticle―quantum dots through the nasal administration of ICR gyno-mice, we use the optical imaging technologies in vivo with fluorescence and the fluorescence microscope to analysis the distribution of quantum dots in the olfactory bulb and central nervous system of mice and the time-variation of fluorescence intensity after exposing 10minutes,30 minutes,1hour,2 hour,4 hour,12 hour,24 hour,48 hour. Fluorescence spectrum proceeding in Molecular Devices determined the stability of quantum dots in the physiological condition and in the need solution which was used in the tissue slice. RESULTS: The nanoparticle―quantum dots which put into issue slice solution had fluorescence intensity after 72 hour,moreover,it is most stable in the neutrophilia solution。Using the optical imaging technologies in vivo with fluorescence we found the quantum dots extended to the olfactory bulb in 30 minutes;1 hour later,there wasn't any change in fluorescence intensity, 2 hour,4 hour,12 hour later,the fluorescence intensity in nasal cavity turn weak gradually,but the fluorescence intensity in olfactory bulb was still saw. 24 hour,48 hour later,the fluorescence intensity of quantum dots aggregated in olfactory bulb and disappeared in the front of nasal cavity. Using the fluorescence microscope we found in the tissue slice the quantum dots was in the front of olfactory bulb after 30 minutes. 1hour later the quantum dots entered into the olfactory bulb and transferred into deep layer of olfactory bulb,2 hour,4 hour,12 hour later, there wasn't any change in fluorescence intensity. 24 hour,48 hour later,the fluorescence intensity of quantum dots turn weak and transferred into cerebrum.CONCLUSIONS: 1. Quantum dots can stabilize in the need solution which was used in the tissue slice. 2. quantum dots can entered into cerebrum and aggregate in the olfactory bulb by the mucous membrane of nose after nasal inhalation,24 hour later,the fluorescence intensity of quantum dots transferred into cerebrum,the fluorescence intensity in olfactory bulb was turn weak gradually.