Blood Detection Of Cancer Based On Hydrogel Photonic Crystal Microbeads

Following the huge increase in the amount of biomolecular information that must be accessed for research and clinical purposes,there has been increasing importance of bioassay to determine the biological activity or specific functional response of a substance,nowadays a large number of technologies that encompassed applications in functional analysis of unknown genes,screening in drug discovery and clinical diagnostics have been developed.With the increasing demand for a multiplex and high throughput analysis of large numbers of biomolecules,the multiplex technology,which allow multiple discrete assays to be performed simultaneously within the same microvolume sample,is the promising tool to carry out thousands of individual reactions all at the same time for large-scale biological analysis,and suspension array that uses barcode particles as the microcarriers has emerged as a popular technology for the application in various multiplex bioassays of different fields including food safety,drug discovery,clinical diagnosis and biodefense.At present,there are a great deal of encoding technologies that have been proposed for the development of barcode particles,such as fluorescent encoding,graphic encoding,electronic encoding,chemical encoding and so on.Although the fluorescent barcode particles have achieved great success in commercialization,they also have some problems,such as encoding missing and encoding interference.However,another optical encoding technology,photonic crystal encoding,can completely avoid these problems,and has the advantages of stable encoding and large encoding amount,and thus has been used in the research of multiplex bioassays.This dissertation discussed the applications of different functional hydrogel photonic crystal microbeads in multiplex tumor detections,and the works are divided into the following three parts:(1)Multiplex detection of tumor markers based on novel composite hydrogel photonic crystal microbeads.A new type of agarose-poly(ethylene glycol)diacrylate(PEG-DA)composite hydrogel photonic crystal microbeads was prepared,and the conditions of immobilization of biological probe molecules and detection of tumor markers were optimized.Under optimal conditions,quantitative analysis of tumor markers was performed using double-antibody sandwich method,and the standard test curves were also established.Finally,the feasibility of multiplex detection was verified and clinical samples were tested to determine the accuracy of the results by comparing with clinical method.(2)Multiplex detection of tumor-associated miRNA based on core-shell hydrogel photonic crystal microbeads.To improve the encoding stability of hydrogel microbeads,core-shell hydrogel photonic crystal microbeads were prepared,in which silica photonic crystal cores were used for stable encoding and the hydrogel shells were used for bioassays.Under optimized conditions,the detection of the target miRNA was completed,and the signal amplification was also performed by using the rolling circle amplification method to improve the sensitivity.Finally,the feasibility of multiple detection was confirmed.(3)Multiplex capture of circulating tumor cells based on aptamer-modified magnetic hydrogel photonic crystal microbeads.Due to the small number of circulating tumor cells in the blood,magnetic hydrogel photonic crystal microbeads were prepared for the sufficient contact between microbeads and cells,they can be moved to any position of the reaction system under magnetic field for capture.Bacteria,as a simple cell-structure organism,were first used to confirm the superiority of magnetic hydrogel photonic crystals and the feasibility of multiplex capture.