Synthesis Of PH-sensitive ZnO Nano-drug Carrier And Study On Its Drug-carrying Performance

In recent years,the rapid development of nanomedicine has great potential in the treatment of cancer.For example,smart nanocarriers enable targeted therapy,and semiconductor quantum dots?QDs?can serve as bioluminescent probes.Among them,the low cost and low toxicity of ZnO quantum dots has attracted people's attention in the biomedical field.It has been reported that ZnO quantum dots can stably exist in a p H 7.4 environment,but quickly dissolve into Zn2+ ions at p H < 5.5,which allows the drug to be delivered before it is delivered to a specific lesion,and it can be quickly reached after reaching the site of action.Release the drug for sustainable drug delivery.However,due to the poor quantum yield and poor water stability,the further application of ZnO quantum dots in the biological field is hindered and must be modified.The main research contents of the paper are as follows:1.A novel ZnO QDs macromolecular drug carrier based on electrostatic interaction was synthesized.The positively charged ZnO-NH₂ QDs were synthesized in ethanol,and then the negatively charged anion PAA-PEG-FA was electrospun to form a core-shell nanostructure ZnO@?PAA-PEG-FA?.1H NMR,XRD,TEM and UV were used to characterize the synthesis of ZnO-NH₂ QDs,the synthesis of PAA-PEG-FA,the formation of nano-particles,and their drug-loading properties.The cumulative release rate of the drug at p H 5.0 was high,within 48 h.The cumulative release rate of DOX reached 90.5%,while the cumulative release rate of DOX at p H 7.4 was 15.3%.The nanoparticle has p H dependence and exhibits a good sustained release performance.The nanoparticle has great development prospects as an anticancer drug carrier.2.Synthesis of P?PEGMA-VI-FA?block copolymer modified ZnO QDs carrier,Cd Te/Zn S QD as imaging agent nano drug carrier: ZnO@?PEGMA-VI-FA?@Cd Te/ Zn S.The 1H NMR proved that the polymer PEGMA-VI-FA was successfully prepared;TEM proved that the vector had good stability in aqueous solution,the particle size was 4 nm;the drug loading was 25%;the cumulative release of drug was higher at p H 5.0,48 h The cumulative release rate of internal DOX reached 95%,while the cumulative release rate of DOX at p H 7.4 was 13%.The cytotoxicity experiments showed that the nanomedicine had less cytotoxicity in the cell,the cell survival rate was >70%,the IC50 of the vector to B16-F10 cells was 1.45 ?g/m L and 1.28 ?g/m L;the fluorescence microscope proved that the drug carrier had Cd Te/Zn S red fluorescence.Can do cell imaging agent.3.Synthesis of DTPA block copolymer modified active and passive targeted water-soluble ZnO QDs drug carriers.The monomer DTPA was synthesized first,and the block polymer P?PEGMA-VI-DTPA?was formed by RAFT polymerization.Then the ZnO QDs were encapsulated by polymer to form ZnO@?PEGMA-VI-DTPA-PBA?QDs nano drug carrier,and finally the technetium and radioactive Nuclide 99 mTc Forms Diagnosis and Treatment System ZnO@?PEGMA-VI-DTPA-99mTc-PBA?QDs.UV/Vis was used to determine the water solubility and stability of the synthesized ZnO QDs nano drug carrier and drug loading performance after loading DOX.The cumulative release of drug was higher at p H 5.0.The cumulative release rate of DOX reached 91% within 48 h,while the cumulative release rate of DOX was 14.5% at p H 7.4.The IC50 of the vector to B16-F10 cells was 1.21 ?g/m L and 1.18 ?g/m L.The small animal SPECT imaging experiment achieved a combination of diagnostic-therapeutic systems.