Extraction And Characterization Of Tumor-Related Cell Exosomes And Research On Application Methods Based On Aptamers

Exosomes are small extracellular vesicles with a diameter of 30-150 nm that all cells produce and secrete autonomously through biological mechanisms.In recent years,exosomes have developed rapidly in the medical field,and have been widely used in the diagnosis and treatment of various pathological diseases,especially in the diagnosis and treatment of cancer.The aptamer is one of the important ways for the extraction and application of exosomes.Compared with antibodies,aptamers have the advantages of stable chemical properties and no immunogenicity.Therefore,using aptamers to isolate and detect exosomes is a more promising option.At present,aptamers related to exosomes only stay at the content level of exosomes.There is no report on the aptamers of intact exosomes.Different exosomes have various types of differences due to their different cell sources.For example,if they can screen out the aptamers of complete exosomes,the separation or identification of exosomes using aptamers will be more accurate.Test strip technology is a fast and convenient detection method.For example,the combination of test strip technology and aptamers can be used for qualitative detection of exosomes,which will provide a new method for exosome detection.In this project,two different types of tumor-related typical cells were selected,human umbilical vein endothelial cells(HUVEC)and non-small lung cancer cells(A549),and the exosomes of the two cells were extracted and characterized respectively.Taking HUVEC exosomes as the target,4 ?m aldehyde-based latex beads were used to enlarge their particle size,and nucleic acid aptamers were screened,and the screening conditions were optimized.Although the screening results are not ideal,this part of the experiment is still useful for the screening of intact exosome aptamers.In addition,this topic developed a test strip sensor that can be used to quickly detect A549 exosomes,which can detect exosomes with a concentration of 6.4 × 109 particles/mL.This topic provides a new method for the visual detection of exosomes.method.