Preparation Of Biodegradable Multifunctional Nanomaterials And Their Applications In Tumor Therapy And Analysis

With the progress of nano technology,functional nanomaterials have been rapidly developed in the field of biomedical and life analysis.A large number of functional nanomaterial-based sensing analysis strategies and tumor thearpy applications have been widely reported.But with the development of the research,biological toxicity of nanomaterial had got more attention,if not control the nanomaterials toxicity,the established sensing analysis and tumor therapy strategy will in the risk of potentially toxic effects,and hinder the transformation application.On the other hand,the toxic effects of materials may lead to the "distortion" of the analysis in living cells and body,leading to the mistake of the analysis results,and then cause serious secondary damage.Therefore,developing the degradable nanomaterials could further promote their life analysis and cancer therapy application.The main research contents of this paper are as follows:1.We have built a biodegradable organic source and prepared silica nanoparticles,by optimizing the rate of organic degradable silicon and TEOS,realized the equilibrium stability of biodegradable properties and their morphology control.The biosecurity of the constructed biodegradable silica nanoparticles was tested by in vitro cell model and in vivo animal model.Dendritic mesoporous silica particles with different morphology and channel types were prepared by using the two-phase interface method to meet the better performance requirements of different applications.2.Based on the prepared biodegradable silica nanoparticles,with the loading of Cy-GGT probe and GGT m RNA,the cooperative detection of glutamyltranspeptidase(GGT)activity and GGT H-type m RNA mutation in cells were realized.Through spectral response experiments,the specificity of the organic small molecule probe and the nucleic acid recognition structure were tested.The results showed that the crossinfluence effect of two strategies was weak in the analysis performance,although there was less cross-interference in the spectrum.The cooperative application of the two analytical methods have shown the advantages of their own performance in one analysis system,broadened the scope of analysis objects,realized the combined application of organic small molecule probes in the active biological enzymes detection and nucleic acid sequence recognition by nucleic acid structure,and provided an new consideration for the related work in life analysis filed.3.Based on the biocompatibility of nucleic acid nanomaterials and their strong interaction between chemical drug doxorubicin(DOX)and nucleic acid sequence,the biodegradable DNA-drug nano-particles were prepared.By modification of HER2 aptamer on the surface,the nano-particles could have higher uptake and utilization efficiency for tumor cell lines with high expression of HER2.With the degradation of nano-particles,Cp G nucleic acid fragments could be relased by the death of tumor cells and would generate immune stimulation in tumor microenvironment,promote the antigen processing efficiency of dendritic cells.Therefore,combined with antigenic substances release that caused by the destructive effect of DOX chemotherapy,the“cold” tumor tissue could be transformed into “hot” tissue and immunosuppression can be reduced to achieve synergistic immunotherapy.The established strategy is expected to reduce the impact of tumor resistance and enhance the suppression of distal metastasis and recurrence by using the advantage of the immune response in body.