Preparation And Application Of PH Sensitive Drug Carrier Based On CaP Nanoparticles

Calcium phosphate nanomaterials were often used as a carrier of drug/genetransfer delivery because of its great pH sensitivity. While calcium phosphatenanoparticles that have been formed now are not of uniform size and easy to gatherwhen kept in water. In order to solve these problems, the W/O micro-emulsion systemwas used for the formation of calcium phosphate nanopartices，and explored theinfluence of different factors to the morphology of calcium phosphate nanoparticles.Also, PLGA and BSA-PLGA were used to modify CaP nanoparticles. The specificcontents are as follows:(1) Preparation and characterization of CaP nanoparticles. The influence ofdifferent water oil ratio, reactant concentration and reaction time in preparing calciumphosphate by W/O micro-emulsion system were studied in detail. The results showedthat: the FTIR, EDX, XRD and other series of characterization methods haveconfirmed that the calcium phosphate nanoparticles were successfuLly prepared, andcalcium phosphate nanoparticles can disperse evenly and was spherical whencyclohexane: hexanol: Trition was8:4:6, the concentration of reactants were250mMand reaction time was30min. The resulted particles dispersed well with the diameterof60~90nm and nagative surface charge (-16~-8mv).(2) The pH sensitive experiment of CaP nanoparticles. Doxorubicin was loadedinto CaP nanoparticles with a decent drug loading content, and then in vitro DOXrelease was conducted in different environment, the results showed that: Afterincubation at pH5for24h, about90%of the DOX originally encapsulated withinCaP nanoparticles was released into the medium while only about48%of the DOXreleased at pH7.4for24h which proved that the pH sensitivity of CaP nanomaterials.(3) The modification of CaP nanoparticles by PLGA. Emulsification method wasused to modify the CaP nanoparticles. The results showed that: FTIR, EDX haveconfirmed that the CaP/PLGA nanoparticle was successfully prepared with thediameter of about200nm.(4) Cytotoxicity and cellular uptake of CaP and CaP/PLGA nanoparticles. MTTassay showed little cytotoxicity of CaP and CaP/PLGA nanoparticles. Cellular uptakeof DOX-loaded CaP ans CaP/PLGA nanoparticles by fluorescence microscopy confirmed it can successfully deliver and release DOX into cytosol of Hela cells.(5) The modification of CaP nanoparticles by BSA-PLGA. Amphiphilic polymerBSA-PLGA was used to modify CaP nanoparticles through the emulsification methodand the particle size, and morphology of the particles were observed. The resultsshowed that: The CaP nanoparticles midified by BSA-PLGA dispersed well with thediameter of about100nm.In a word, well dispersed CaP nanoparticles were prepered throug W/Omicro-emulsion system. Calcium phosphate nanoparticles tend to gather together inwater and the modification of CaP nanoparticles solved the problem well which madea contribution for the better use of CaP nanoparticles.