Design,synthesis And Research Of Novel Precise And Intelligent Anti-tumor Nano-drug Carrier

With the rapid development of nanotechnology,the effective combination of nanotechnology and tumor biomedicine has gradually become one of the research hotspots in the field of nanobiomedicine.Nanotechnology has shown great potential in the diagnosis,imaging and treatment of cancer.In vivo,nanoparticles produce enhanced permeability and retention effects?EPR effects?due to their size advantages,which can produce effective enrichment at tumor sites,increase the efficacy of nanoparticles and reduce systemic side effects.Based on the application of hyaluronic acid in tumor cells,bio-orthogonal chemistry and glycol-metabolic engineering,three different targeted therapeutic systems for nano-drug loaded tumors were designed and constructed for the orthogonal reaction of skeleton and organism.The main research contents are as follows:1.Sythesis and study of hyaluronic acid-based enzyme and pH dual-response nano-drug delivery system:Hyaluronic acid?HA?is a natural biopolymer that can target to tumor cells due to CD44 receptors overexpressed in tumor cells.Here,a theranostic nanoparticle HA-Ce6?DOX?with enzyme and pH dual-responsive is presented,which combined HA and a highly promised photosensitizer chlorin e6?Ce6?using adipic dihydrazide?ADH?as a linker.The hydrazide group on its surface can efficiently conjugate doxorubicin to form HA-Ce6?DOX?nanoparticles through the pH-sensitive hydrazone bond.In this study,the dual-response of HA-Ce6?DOX?nanoparticles in the tumor cell are discussed.The HA-Ce6?DOX?nanoparticles showed an average size of 90 nm with a uniform spherical morphology.In vitro drug release studies showed that HA-Ce6?DOX?accomplished rapid drug release under acid conditions and enzyme stimulating.Confocal images revealed that the nanoparticles enhance the cellular accumulation of DOX and Ce6 in A549 cells.The therapeutic efficacy of HA-Ce6?DOX?nanoparticles in A549 cells in vitro was evaluated through the MTT assay.The results showed that the therapeutic efficacy of HA-Ce6?DOX?nanoparticles against A549 cells was remarkably enhanced compared with free DOX and free Ce6.These results indicate that the HA-Ce6?DOX?nanoparticles could be a promising delivery system for photodynamic therapy and chemotherapy.2.Study on the combination of salmonella YB1 and photodynamic nanoparticles for tumor treatment:Metabolism of Ac₄manAz was used to introduce azide?N₃?on the surface of salmonella YB1?YB1-N₃?.Meanwhile,on the basis of previous studies,HA-Ce6 was used to connect dibenzocyclooctene group?DBCO?to synthesize HA-Ce6-DBCO nanoparticles.HA-Ce6-DBCO and YB1-N₃ were connected to HA-Ce6-YB1 by click chemical reaction.Photosensitizer Ce6 can be introduced into tumor cells by bacterial anaerobic targeting.The average particle size of HA-Ce6-YB1 was determined as 1394.959nm by the Dynamic light scattering particle size tester?DLS?,with uniform size.The biomarkers test was observed by confocal microscopy,and all the bacteria connected with HA-Ce6 showed obvious Ce6fluorescence.In addition,the confocal images of the cells showed that HA-Ce6-YB1 could release Ce6 in the cells very well.MTT assay was used to study the cytotoxicity of HA-Ce6-YB1 on MB49 cells in vitro.It is expected that bacteria combined with photodynamic particles will be a new and effective method for tumor treatment.3.Study on the Bio-Orthogonal tumor targeting system based on glycol-metabolic engineering:T cells can kill tumor cells by cell surface immunological recognition,but low affinity for tumor-associated antigens could lead to T cell off-target effects.Herein,a universal T cell targeting strategy based on bio-orthogonal chemistry and glycol-metabolic engineering is introduced to enhance recognition and cytotoxicity of T cells in tumor immunotherapy.Three kinds of bicycle[6.1.0]nonyne?BCN?-modified sugars are designed and synthesized,in which Ac₄manBCN shows efficient incorporation into wide tumor cells with a BCN motif on surface glycans.Meanwhile,activated T cells are treated with Ac₄galAz to introduce azide?N₃?on the cell surface,initiating specific tumor targeting through a bio-orthogonal click reaction between N₃ and BCN.This artificial targeting strategy remarkably enhances recognition and migration of T cells to tumor cells.Such a universal bio-orthogonal T cell-targeting strategy might further broaden applications of T cell therapy against tumors and provide a new strategy for T cell modification.