| The physiological and biochemical functions of Vitamin C are because of its action as electron donor. Recent pharmacokinetic data showed that a high level of ascorbic acid can be used as a precursor for the generation high flux of H2O2 for solid tumor tissue. At present the research of nano drug carriers mainly weigh its intelligence, targeting, little of tumor inhibition from nanocarriers had been studied. On the basis of maintaining the functionality of the nanocarriers, we use co-assembly approach to form complex nano-delivery systems with polyvitamin C as a hydrophilic shell. Systematic research was performed on their co-assembled form, in vivo and in vitro inhibition of tumor cells. Also, this dissentation focuses on the complex nano-delivery system itself inhibition of tumor cells, and synergistic effect of inhibiting the tumor cells along with chemotherapy drugs.The main work of this thesis is as follows:1. According to two synthetic route of amphiphilic block polymer existing in the laboratory, polymer polylactic acid-block-poly acrylic ester vitamin C (PLA62-block-PAAA12) and polylactic acid polymer-embedded polyethylene glycol (PLA150-PEG90-Maleimide) was synthesized successfully.Their chemical structures were characterized by nuclear magnetic resonance(NMR) and gel permeation chromatography (GPC).2. The polymer PLA62-block-PAAA12 and PLA150-PEG90-Maleimide were co-assembled to prepare homogeneous complex nanoparticles solution. The nanoparticles morphology and antioxidant capacity were examined by transmission electron microscopy(SEM), scanning electron microscopy (TEM) and uv-vis spectrophotometer(UV). Results show that the formation of the nanoparticles was nanowires, remain more than 80% of the DPPH free radical clearance after 48 h in vitro.3. The complex nanoparticles were applied to the study of systematic cell experiment in vitro. Cytotoxicity of complex nanoparticles was examined by fibroblast cells NIH 3T3 using cells'activity assay method(MTS), and the results showed that complex nanoparticles have good compatibility of normal cells under concentration of 0.8 mg/mL; By measuring complex nanoparticles EC50 values of different tumor cell lines, four kinds of tumor cells were welled inhibited of which EC50 value is the most sensitive to complex nanoparticles, was 18.8?g/mL (corresponding to the vitamin C concentration was 10.2 ?M); Flow cytometry instrument(FCM) with PI and Annexin V double staining studied the complex nanoparticles on C6 and MCF 7 cell apoptosis and complex nanoparticles exhibited good role of inducing apoptosis of C6 and MCF 7cells under 0.8 mg/mL; Also, the complex nanoparticles marked by fluoscence technique can enter the C6 and MCF 7 tumor cell membranes.4. With Paclitaxel as model drug, we study the synergistic effect of complex nanoparticles with drug molecules. Paclitaxel as model drug was encapsulated in the complex nanoparticles and the release behavior of Paclitaxel was measured by UV technique, Paclitaxel was slowly released and reached 80% after 72 h incubation without burst release; We carried the joint by MTS method and FCM to investigate tumor inhibitory effect of complex nanoparticles loading Paclitaxel and the results show that complex nanoparticles and Paclitaxel has a certain synergy, complex nanoparticles mainly play the role of tumor suppressor before 48 h, while drug molecules Paclitaxel contained in complex nanoparticles play a role of tumor suppressor after 48 h.5. The blood compatibility of complex nanoparticles studied on the basis of cells experiments in vitro, the experimental results of thrombus elastic graph (TEG) and blood gas analysis show that 18.6 mg/mL complex nanoparticles has good biological compatibility by tail intravenous medication; Examine tolerance of the normal nude mice to 19.2 mg/mL complex nanoparticles loading Paclitaxel and nude mice weight did not significantly reduce after subcutaneous injection, the results show that complex nanoparticles in under the condition of injection is safe On the biological. |
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