Studies On Preparation And Cell Adhesion Characteristic Of Receptor-mediated Adhesion Powder

The fourth generation drug delivery system is targeting drug delivery system. It includs initiative targeted preparation, passivity targeted preparation and pro-drug targeted according to the source power of target. By antigen-antibody or ligand- receptor action drug should be delivered to target tissue or target cell directly,much with cancer for initiative targeted preparation. Arg-Gly-Asp-Ser(RGDS) peptides ,which are basic formant of different kinds of stroma protein,are able to bind with integrin receptor of cell surface, pitch multi-cell adhere receptor and possesses characteristic of cell fix, cell livability influence.The aim of the thesis is that biodegradable and biocompatible chitosan are prepared to targeting microspheres for glycyrrhizic acid by specificity coherent capability of RGDS ligand and integrin receptor of cell surface. The relationship was studied between phy-chemical parameters and microspheres shaped. It was studied that the kinetic release model, stability and powder characteristic of drug-loaded microsphere, which could supply experiment and theory instruction for its application. Several conclusions have been obtained as follows: ①Taking the single factor design, uniformity design the relationship of parameter and microsphere capability was researched. The multi-element equation of linear regression were got by statistics soft ware SPSS analyses as follows:Y=48.140-10.370X1-1.600E-02X3+28.364X4-29.196X5,r = 0.915( diameter size); y=-22.761+30.454X1-2.697E-03X3+8.596X4-10.811X5, R=0.946(loading efficiency);y=0.277+0.350X1-2.013E-04X3+9.079E-02X4-0.162X5,R=0.953(drug loading).Experiment value of response variables of chitosan microsphere coincide with predicted values according to regression equations under optimal experimental parameters. It was a well spherical form with mean diameter 2.78um, loading efficiency 80.26%and drug loading 1.25%.②Exploiting adsorption method RGDS was grafted in chitosan drug loaded microsphere. By infrared image spectra and Coomassie brilliant blue method formation of drug loaded microsphere, graft RGDS success as well as intermolecular interaction of drug and drug carrier could detected,which form co-precipitation. ③Cell adhere experiment confirmed that RGDS-microsphere possessed RGDS activity, coherent ability between microsphere and cell,which realized microsphere targeting to cell in vitro.④The stability and powder characteristic experiment of the chitosan microsphere indicated result as follows: microsphere was sterilized by 60Co radiation method; preserved under room temperature and 4℃ condition;Basic requirements of inhaled powder could be satisfied.