Study On The Treatment And Imaging Efficiency Of Fluorescent Nanoparticle On PDX Model

Background: In China,the provinces and regions with distorted Taihang Mountains have a higher incidence of esophageal cancer than the general population.Due to their unique terrain,lifestyle,dietary habits and genetic susceptibility,the esophageal squamous cell carcinoma(ESCC)was the most common.When people suffered from esophageal cancer,the patient can appear progressive deglutition difficulty and coarse hard food.When swallowed,there will be a burning sensation with retrosternum,and occasionally translucent,sticky secretions of vomiting.Esophageal cancer is a malignant tumor of digestive system,which is easily transferred to liver through portal vein,lung,bone,lymph node,and even brain and pericardium through blood circulation.The severity of the disease depends not only on the degree of dysphagia,but also on whether the distant metastasis of the tumor causes an organ crisis.Therefore,accurate imaging is very important for clinical staging and target lesion determination.With the development of nanotechnology,nanomedicine has become a new technology and new method to assist in tumor diagnosis and treatment.Bioresponsive nanosystems show promising applications in bioimaging diagnosis,drug delivery,tissue engineering and biosensors.Make drugs "intelligent recognition" to achieve accurate treatment.Small molecule fluorescent dye indocyanine green(ICG),as the only near-infrared fluorescent dye approved by FDA,is a medical water-soluble fluorescent dye with near-infrared(NIR)absorption and emission spectrum.ICG has weak self-fluorescence,low interference,low toxicity,high affinity,and is easy to combine with proteins to form non-covalent fluorescent complexes.However,due to its bleach property,it cannot be stable and targeted for imaging.Paclitaxel(PTX)is a natural anticancer drug,which is widely used in the treatment of esophageal squamous cell carcinoma.However,in the course of drug use,the drug composition contained in paclitaxel causes a high probability of adverse reactions,and patients may have abnormal liver and kidney functions,digestive system and metabolic functions,elevated body temperature,bone marrow suppression,hair loss and other conditions after drug use.During the period of medication,the patient’s discomfort will be greatly reduced.Therefore,it is of great significance to improve drug targeting,make it concentrate in tumor microenvironment and kill tumor.Objective: In this study,nanotechnology was applied to achieve extensive removal of tumor tissue,and tumor suppression and accurate imaging of fluorescent nanoreactor were explored.In addition,we will explore the safety and efficacy of nanoparticles in molecular,in vitro and animal levels.Methods: Firstly,the optimal synthesis pathway of fluorescent nanoreactor was explored.The stable nanocore was prepared by comparing paclitaxel and indocyanine green with different concentrations by solvent evaporation method.Then the KYSE150 cells were subjected to repeated freeze-thaw and ultrasonic treatment,and the membrane and surface proteins were obtained by differential centrifugation.Coomassie blue and Western Blot were used to verify and compare the expression of n-cadherin and CD44v6 in whole cell group,cytoplasm group,cell membrane group and nanoparticle group.The synthesized nanoparticles were characterized by particle size analyzer,UV spectrophotometer and transmission electron microscope.MTT assay was used to find the median lethal concentrations of paclitaxel and nanoparticles,which were applied to subsequent experiments.In cell scratch experiment,the group was divided into control group,paclitaxel group and nanoparticle group,and the effects of different interventions on cell invasiveness were compared.Through the detection of average fluorescence intensity of different concentrations of nanomaterials in small animal imager,the optimal concentration of nanoparticles in animal experiments was explored.Fresh tissue samples from esophageal squamous cell carcinoma operation in our hospital were collected to construct PDX mouse model,and nanoparticles were injected through caudal vein.The imaging efficiency was explored by small animal imager.On day 35,the mice were sacrificed,and the tumor size of the control group,the paclitaxel group and the nanoparticles group were compared.The body weight and tumor volume of mice were recorded to verify the toxicity of the nanomaterial.The liver and kidney toxicity of the nanomaterial was confirmed by examining AST,ALT,ALP and CRE in mice by orbital blood sampling.Results:1.Nanoparticles coated with paclitaxel and indocyanine green and coated with tumor cell membrane were successfully constructed by solvent evaporation method and repeated extrusion method.2.MTT and scratch experiments confirmed that nanomaterials coated with cell membranes had better biocompatibility;Approximately equivalent tumor inhibition effect of nanoparticles compared with paclitaxel;3.In vivo experiments show that the fluorescence nanoreactor can achieve accurate imaging of tumor site in PDX model;4.There was no statistical difference in the therapeutic effect between the nanoparticles group and the chemotherapy alone group;The weight of mice in the nanoparticle treatment group was slightly higher than that in the chemotherapy alone group,and significantly higher than that in the control group,P < 0.05.The adverse reactions and toxicity of the nanomaterial were lower than that of the chemotherapy group.5.Nanomaterials can achieve good targeting in both therapy and imaging.Conclusion:1.This method of constructing loaded drug therapy is safe and effective,and can be a valuable application method for drug delivery.2.Nanoparticles can achieve extensive and accurate measurement of tumor lesions,providing new ideas for intraoperative guidance and clinical imaging.3.The nanometer reactor has the function of drug loading,so the nanometer particle has the development potential of edge treatment.