The Preparation Of Nanocomposites For NIR Responsive DrMg Delivery And Photodynamic Therapy

At present,chemotherapy is an important treatment for anticancer.Long term dependence on chemotherapy,the drug resistance of tumor cells gradually increased that directly affects the effectiveness of chemotherapy.Therefore,on the basis of drug chemotherapy,the integration of multiple treatments would greatly enhance the anti-tumor effect.In this thesis,we have prepared the near infrared light stimulated core-shell nanomaterials for anticancer.The preparation,modification/assembly and the relationship between the structure and property of functional core-shell nano materials was also investigated.In addition,the inhibition of multiple integrated treatments?chemotherapy,photodynamic therapy and light hyperthermia?on tumor cells was also studied in detail.The main research content is as follows:?1?NIR light mediated UCNPs@mSiO₂ nanovehicle was constructed as the nanocarrier.Based on the novel UV emission,TiO₂?3.0-3.2 e V?was adopted as the photosensitiver?PS?on account of the high activity and excellent stability.Here,a simple host-assembly method was exploited to graft it onto the inner and outer surface of the mSiO₂ shell.On the other hand,a UV cleavable o-nitrobenzyl derivative linker?TC linker?was prepared as“gate”to encaps?Late anticancer agent doxorubicin?DOX?inside m SiO₂,insuring the few prematurity.Under NIR irradiation,the UV emission can excite TiO₂ to produce reactive oxygen species?ROS?and also can induce the photodegradation of TC linker and dr?g release as well.The detailed release kinetics was studied to reveal that it is TC linker to manipu Late the NIR-sensitive dr?g release and the amount of TC linker also can be used to adjust the release performance.The synergistic action of PDT and chemotherapy displays the improved cytotoxicity of DOX-UCNPs@mSiO₂/TiO₂-TC to He La cells under NIR irradiation that makes the potential application in anticancer field due to the superior to any single means.?2?A UV sensitive silane coupling agent with four arms structure was synthesized as a“gate TG”to constrcuct a near infrared sensitive DOX-UCNPs@mSiO₂/TiO₂-TG nano pharmaceutical system.Compared with the previous study on the properties of DOX-UCNPs@mSiO₂/TiO₂-TC materials,it is found that the"gate"with planar structure is more efficient than the chain structure"nano gate".The dosage was significantly reduced,moreover“TG gate”show the more sensitive response to light.That also provides a new idea for further optimization of“gate”on controlled release.The modification of folic acid was used to enhance the targeting to tumor cells.Withoutt NIR irradiation,the nanocomposite reveals ignorable effect on cells.However,under NIR irradiation,the synergistic effect of chemotherapy and photodynamic therapy showed a significant inhibitory on tumor cells.?3?Fe₃O₄@C nanoparticle,about 100 nm in size,was synthesized via one-step hydrothermal method.With NIR irradiation?808 nm?,Fe₃O₄@C nanoparticle shows a rapid photothermal conversion capacity.The temperature rises by 23.0 and 20.2?with the power density of 3 and 2 W·cm^-2,respectively.However,that of Fe₃O₄nanopartical increases by 12(3 W·cm^-2)and 8?(2 W·cm^-2).The coating of carbon nanolayer not only can improve the dispersion ability of the magnetic nanomaterials,but also enhance the photothermal capacity of the complex.With 808 nm stimulated,the thermal effect of the material has a significant inhibitory effect on tumor cells...