Synthesis And Applications Of Glypolymers-based Fluorescent Probes

Glycopolymer is a natural or synthetic polymer,which has functional groups of carbohydrates, especially the polymers, having the sugar units in the side chains. Sugar as an important molecular has an important role in biological and many other life processes, for example: sugar molecules can specifically recognize the protein, involve in many life processes including cell recognition, cell proliferation, signal transduction and pathogen infection, sugar also has the character of hydrophilicity, biocompatibility and biodegradability. In disease treatment, in order to improve the targeting property of drugs, thereby enhancing the treatment effect of disease, appropriate targeting ligands need to incorporated, glycopolymer is one promising candidtate. Using the specific recognition feature of sugar, glypolymers are also widely used in biomaterials, chiral recognition, signal sensing and other fields.Herein, variable polymer synthetic methods have been used to synthesize glycopolymers, to enhance the water solubility and stability of obtained materials. In addition, it can reinforce the ability of polymer with cell specific recognition and biocompatibility. Meanwhile, its application in biological aspects was studied.Fluorescent probe is a dye, which can emit fluorescence when absorbing light with certain wavelength. Because of the visual and convenient characteristics of fluorescent probe, it has been widely used for imaging and biomarkers in the biological field.Our goal is to synthesize a series of glycopolymers with fluorescence using advanced polymerization methods, study their recognition with proteins and cells, and to explore the application in cellular imaging, cancer treatment and monitoring p H of cells. Specific research in this paper is as follows:(1) Microwave-Assisted Synthesis and Application of Glycopolymer-Functionalized Silver Nanoclusters.First, we prepared a series of different molecular weight polymers using a reversible addition-fragmentation chain transfer(RAFT) polymerization process, adjusted the p H value, then adding silver nitrate solution with the assist of microwave to achieve the glycopolymer-functionalized silver nanoclusters. Experimental results showed that the silver nanoclusters have the uniform size, strong fluorescence and are stable in aqueous solution. Meanwhile they also have good capacity to recognize the lectins and cancer cells, a high yield of Reactive Oxygen Spcies(ROS), and high cytotoxicity toward cancer cells.(2) Preparation and properties of p H-senstive glycopolymer-based fluorescent probeThis study combines RAFT polymerization and "click chemistry"(Click Reaction) to prepare sugary fluorescent probe. Firstly, Fluorescein O-methacrylate and monosaccharides were synthesized by RAFT polymerization, secondly, Acryloxyethyl thiocarbamoyl Rhodamine B was "clicked" onto the polymer chain. Experimental results showed that the fluorescent probe has good response to p H changes. With the increasing p H between 5 to 9, the fluorescence intensity of FITC increases, the fluorescence strength of RBITC remained unchanged, meanwhile the polymer is almost non-toxic and has good biocompatibility, and it can be applied in monitoring the p H changes in cells.