Design Of Novel Nanoprobe And Its Application In Tumor Diagnosis And Treatment

Aggregation Induced Emission(AIE)effect is a phenomenon that molecules do not emit light in solution but produce strong fluorescence in solid state,which was first reported by Professor Tang Benzhong's group in 2001.In the past two decades,AIE based on the basic theory,molecular design and cutting-edge application research has made great progress,and become the current research hotspot.In the basic theory of AIE,a cluster-induced luminescence theory system based on the restriction of intramolecular motion and supplemented by other mechanisms has been formed.In terms of molecular design,the free moving benzene ring is mainly used as the basic structural unit to carry out molecular self-assembly to construct light-emitting nanoparticles.Meanwhile,new materials such as benzene ring are developed to further improve the performance of light-emitting nanoparticles.In terms of applications,AIE nanoparticles show great potential in biomedical and optoelectronic devices,including biological imaging,precision tumor therapy,perovskite carrier research,organic light-emitting diodes(OLED),etc.AIE has the advantages of low preparation cost,low background noise,high optical stability and long time fluorescence tracking.However,in the current AIE research field,there are few molecular species,low quantum yield,poor stability,and long-term follow-up will bring some biological toxicity,which limit its clinical application.In this paper,AIE nanomaterials with high stability,high brightness and high photothermal conversion efficiency were prepared by rational molecular design and the introduction of novel materials,which were used in biological imaging and tumor treatment research.The details are as follows:(1)Construction of soft nano-fluorescent probe based on amphiphilic AIE molecule to study the processes and mechanisms of cell uptake and effluent.It was found that the soft AIE nanoparticles could be quickly removed from the cells,effectively reducing the cytotoxicity.Cp G was further used to construct immune reagents to activate cellular immunity,and it was found that the immune activation of cells could be effectively realized.(2)To construct a highly stable gold nanocluster-tetraphenylvinyl composite probe for highly sensitive imaging and photothermal therapy of tumors.In order to solve the problem of low heat conduction efficiency and poor stability of gold nanoclusters,the surface of gold nanoclusters was modified with TPE molecular rotor ligand,and the photothermal nanomaterials with molecular rotors were constructed and used for the photothermal therapy of tumors.The introduction of ligand significantly improved the thermal conductivity and photothermal stability of the material,and achieved 95% inhibition rate.(3)Using fluorescent labeled two-dimensional DNA origami as an imaging probe for liver cancer,we studied the process and mechanism of two-dimensional DNA nanostructures targeting liver metabolism and tumor.It was found that two-dimensional DNA origami could be quickly removed from the liver,and the accumulation time of the probe in the tumor was prolonged by tumor penetration and uptake of tumor phagocytes,thus achieving high contrast imaging of liver cancer.In this study,a variety of novel nanomaterials were designed and synthesized by using aggregation-induced luminescence molecules as structural elements to construct stable photothermal conversion nanomaterials for imaging and tumor therapy in both cells and in vivo.