Study On Building Method Of Functional Polysaccharide Quantum Fluorescent Probes

Polysaccharides,playing an important role in life activities,have different kinds of functions,include biological information transfer,anti-tumor,anti-inflammation,immunoregulation and so on,and more and more researchers pay attention to it.However,many reasons,which are complex biosynthetic mechanism,high molecular weight,many hydroxyl and branches structures and the research methods limitation,result in the study of polysaccharides are lower than protein.Biomarker is one of important method to study molecular mechanism of polysaccharides.So to find a convenient and practical biological label to the study of the mechanism of polysaccharides becomes particularly important.Quantum dots have many advantages include stable optical properties,size adjustability and so on,which provide a new way for building polysaccharide probes.This paper aims to build a sample,fast,visual polysaccharide fluorescent probes.We mainly used two methods to construct polysaccharide fluorescent probes.The first method,we make use of a biotin-streptavidin linkage to prepare the polysaccharide fluorescent probes.The experiment was able to get the polysaccharide fluorescent probes by self-assemble of two kinds of complexes,which are Streptavidin-Quantum dots complex and biotin-polysaccharides complex.Experiments also used Ganoderma tsugae polysaccharides SBT which was prepared by our laboratory to verify this method.The results show that the polysaccharide fluorescent probe can specific bind to the receptor on the surface of macrophages cell THP-1,and the optical properties of polysaccharide fluorescent probes are stability and not being quenched easily.The second method,we adopted the approach of directing synthesis to reduce the waste of samples and the shortcomings of long synthesis time.Experiments used bovine serum albumin(BSA)as a bridge to block the effect of Quantum dots on the structure of Dextran.Firstly,Dextran was covalently attached to BSA.Secondly,Quantum dots were attached to BSA-Dextran compounds,and self-assembling polysaccharide fluorescent probe.Experimental results show that the polysaccharide fluorescent probe can bind to the polysaccharides' receptors on the surface of THP-1 well,and the method is simple,and the probe has excellent fluorescent intensity.Both methods have their own advantages,the former has the activity of specific binding,the latter's method is simple,which paves the way for building polysaccharide chip,screening polysaccharides' receptors and measuring polysaccharides' receptors.