Preparation And Optical In Vivo Imaging Examination Of β-Cyclodextrin Amphiphilic Copolymers Micelles

Polymeric micelles as a common carrier of sustained release drug delivery systems,its applications in pharmaceutical formulations have many advantages. “core-shell”structure of polymeric micelles can not only improve the solubility of poorly soluble drugs,but also make the drug reaches the effect of sustained release. Nanoparticle size of polymeric micelles can enhance drug permeability of physiological membrane and vascular wall. Low critical micelle concentration of polymer micelles can ensure the stability of the system.Amphiphilic polymer material is the key of polymeric micelle to be effective. In this work, extracts derivatives vinpocetine(VIP) of vinca are take as model drug, to study the performance of drug loaded of β-cyclodextrin amphiphilic polymer(β-CD-[P(AA-co-MMA)-b-PNVP]4), and to study the physicochemical properties and in vitro release properties of drug-loaded micelles. The subject also to develop fluorescently labeled micelles, and Optical in vivo Imaging technology is taken to study the in vivo distribution conditions of theβ-CD-[P(AA-co-MMA)-b-PNVP]4 micelles. The main contents are as follows.1. Taken the synthesis of β-cyclodextrin amphiphilic polymer(β-CD-[P(AA-co-MMA)-b-PNVP]4) as materials and VIP as model drug, to develop VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles. Firstly, to examine the process for preparing drug-loaded micelles(method of dialysis, method of thin film hydration, and method of solvent evaporation), results showed that the method of solvent evaporation is most suited for preparing drug-loaded micelles. For the use of solvent evaporation to prepare VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles, taken the drug loading as main indicators, factors maybe effect the results of micelles are examined, including the type of organic solvent, mixing sequence of the organic phase and aqueous phases, volatilization temperature, volatilization speed, volatilization time, the amount of organic solvent, theamount of water, the weight of material and the dosage of model drug. Then using Box-Behnken design of response surface methodology, evaporation rate, volatile time,dosage of drug and amount of organic solvent are taken as independent variables to optimize the preparation of VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles, the result showed that the best combination of four factors are evaporation rate 1148 rpm, volatile time 2.3h, dosage of drug 0.056 g, the amount of methanol 34 m L. The average drug loading of VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles is 24.14%.2. Investigated physicochemical properties and in vitro release properties of VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles. Method of Pyrene fluorescence measured the critical micelle concentration of micelle materialβ-CD-[P(AA-co-MMA)-b-PNVP]4 is 5.852×10-3 mg/L. Method of dynamic light scattering measured particle size of VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelle is64.4nm and the particle size distribution is 0.278. By using a transmission electron microscope measured VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 is similar to the shape of circular and micelles can be seen "core-shell" structure, through screening lyoprotectant of micelles to known that drug-loaded micelles lyophilized powder can ba stored about 10 day at room temperature. By using Fourier transform infrared spectroscopy drugs, blank micelles, micelles, etc. IR spectra scans confirmed the VIP is wrapped in polymeric micelles kernel. And investigated in vitro release properties of VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles in release media with different p H, the results showed that the drug-loaded micelles have sustained-release effect in different media and that the drug-loaded micelles have p H-responsive.3. Quantum dots(Cd Se-Zn S), and Rhodamine B are used as fluorescently label probe to label β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles, and through inspect the preparation technology to obtain suitable fluorescence strength and suitable particle size fluorescently labeled micelles.By comparing the two fluorescently labeled micelles, known that size of rhodamine B-loaded micelles are closer to blank micelles, and has higher fluorescence intensity.4. Through fluorescence imaging, and mouse tissue fluorescence imaging of fluorescence labeled micelles to ensure that the fluorescence intensity and fluorescence permeability are reached fluorescence imaging capability.Then by intravenous injection,study the distribution conditions of β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles in BALB/c A nude mice, the result showed that after intravenous injection,β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles are mainly characterized by liver accumulation in nude mice.In this work, by studying preparation, physical and chemical properties characterization and in vitro release of VIP /β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles,indicating that VIP/β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles improved the solubility of VIP, and showed that the drug-loaded micelles have sustained-release effect and p H-responsive. By preparing Cd Se-Zn S labeled and rhodamine B-labeledβ-CD-[P(AA-co-MMA)-b-PNVP]4 micelles, and fluorescence imaging, showed that after intravenous injection, β-CD-[P(AA-co-MMA)-b-PNVP]4 micelles are mainly characterized by liver accumulation in nude mice.