| Chitosan has good stability, water-solubility and positive electrical property, which is an excellent biological macromolecule. Because of its particularly suitable for embedding and releasing peptides, proteins, nucleic acids, vaccines and other bioactive molecules, chitosan was concerned by researchers in recent years. In this paper, in order to expand the application range of chitosan and metalloporphyrins, a new type of water-soluble, functional and natural polymer nanoparticles was prepared by the way of coordinate bonding. It was insoluble metalloporphyrins combined with chitosan/ poly (acrylic acid) nanoparticles.First of all, main types of polysaccharide nanoparticles, the preparation methods and applications of chitosan nanoparticles were reviewed.Secondly, the chitosan/ polyacrylic acid nanoparticles (CS-PAA-NPs) were prepared by in-situ polymerization. Then the glutaraldehyde crosslinked chitosan/polyacrylic acid nanoparticles (CS-GA-PAA-NPs) were obtained via glutaraldehyde cross-linking. Four kinds of chitosan/ polyacrylic acid nanoparticles binding porphinatozinc were prepared by the way of complexing different zinc porphyrins with CS-GA-PAA-NPs. And they were characterized by UV-Vis spectra and DLS, which were named as ZnTpMoPP/CS-GA-PAA-NPs, ZnTpHPP/CS-GA -PAA-NPs, ZnToHPP/CS-GA-PAA-NPs and ZnTmMpHPP/CS-GA-PAA-NPs. It was concluded that the system was stable and the size of nanoparticles was uniform. It was conjectured that porphyrinatozinc and CS-GA-PAA-NPs was complexed by coordinate bonding. It was shown that porphyrinatozinc was better dispersed by CS/ PAA nanoparticles than by the solution of mixed organic solvent and water.Thirdly, in this thesis, the functions of CS-GA-PAA-NPs binding porphinatozinc were explored from two aspects, respectively.1) The oxygen free radical scavenging property of CS-GA-PAA-NPs binding porphinatozinc. The synthesis and separation of meso-tetraphenylporphyrins and their derivatives were relatively simple. So they have a broad application in the oxygen free radical scavenging. Metalloporphyrins can be used as enzyme model compound to eliminate oxygen free radicals. To improve metalloporphyrins'hydrophilicity is the main problem need to be solved because free radicals of human body were in a hydrophilic environment. In this paper, the superoxide anion radical scavenging property of CS-GA-PAA-NPs binding porphinatozinc was investigated. CS-GA-PAA-NPs binding porphinatozinc showed excellent scavenging activity compared with the properties of CS-GA-PAA-NPs and porphinatozinc complexes. The EC50 values of CS-GA-PAA-NPs binding porphinatozinc were between 1.99μmol/L and 8.60μmol/L. The degree to simulate the natural SOD enzyme of CS-GA-PAA-NPs binding porphinatozinc was up to 3.02%. The order of scavenging activity of four kinds of CS-GA-PAA-NPs binding porphinatozinc was ZnTpMoPP / CS-GA-PAA-NPs > ZnTmMpHPP/CS-GA-PAA-NPs > ZnToHPP/CS-GA-PAA -NPs > ZnTpHPP/CS-GA-PAA-NPs.2) The photosensitivity of CS-GA-PAA-NPs binding porphinatozinc. In this thesis, the photosensitivity of ZnTpHPP/CS-GA-PAA-NPs was also investigated. The Fluorescence of ZnTpHPP/CS-GA-PAA-NPs can be quenched by methyl viologen (MV2+). The photoinduced electron transfer reaction from ZnTpHPP/CS-GA-PAA-NPs to the water-soluble cationic acceptor (MV2+) in [ZnTpHPP/CS-GA-PAA-NPs] / MV2+/ TEOA system was also studied with durative irradiated illumination. It was shown that ZnTpHPP/CS-GA-PAA-NPs was a good natural polymer photosensitizer. The function of hydrogen production was also explored.In a word, CS-GA-PAA-NPs binding porphinatozinc have good property of scavenging oxygen free radicals and photosensitivity. The application of chitosan and metalloporphyrin has been enhanced, which can provide potential application prospect to develop new polymer antioxiunts, polymer electronic transfer reaction system and new energy.
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