Silica Nanoparticles And Polyamidoamine, The Hydrophilic Carrier Systems For Photosensitizer

As a photosensitizer, zinc phthalocyanine can transform O2 to produce reactive oxygen species by the photosensitization under the excitation of right light. This has caused wide concern in photocatalysed and photodynamic areas. However, the small solubility, easy aggregation property and other issues have greatly limited its application. To develop the suitable carrier system is an important way to solve these problems. Compared to other carrier materials, silica nanoparticles and polyamidoamine dendrimers materials have good biocompatibility, low toxicity, big surface areas, easy biodegradability, and prone to functional modification on their surface. Therefore, they have been widely used in the fields of environmental management and bio-pharmaceuticals. The research topic of this thesis mainly focuses on hydrophilic carriers of silica nanoparticles and polyamidoamine dendrimers. Through optimizing the synthesis methods and processes, the photochemical or biological activity of the photosensitizer is improved significantly. The main research work is as follows.The first chapter was introduction. The development history, photosensitive properties, mechanism and applications of phthalocyanine photosensitizer were summarized. The advantages and current research situation of some important carrier systems, especially the silica nanoparticles and the polyamidoamine dendrimers, impact in the field of photocatalysis and photodynamic therapy were reviewed.In chapter 2, Tetra-a-(2,4-di-tert-butylphenoxy) phthalocyaninato zinc was successfully encapsulated in SiO2 nanoparticles (ZnPc(OAr)4@SiO2) by microemulsion method. It was showed from TEM that the nanoparticles were highly dispersed and uniform in particle size distribution around 100 nm. The nanoparticles were able to degrade two pollutions,2,4,6-trichlorophenol and rhodamine B under the condition of visible light irradiation and oxygen. After being irradiated 270 min, the degradation ratio of 2,4,6-trichlorophenol and rhodamine B were achieved in 95.4% and 47.2%, respectively, at pH 10 under irradiation of visible light (λ≥ 550 nm). The nanoparticles can be recyclicaled and exhibited high photochemical stability. By high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry analysis it revealed that 2,4,6-trichlorophenol mainly degradate to the organic compounds.In chapter 3, the third generation of polyamidoamine dendrimers with amino end group (G3-PAMAM-NH2) was used as carrier of tetra-substituted carboxyl phthalocyaninato zinc (ZnPcC4), thus constructed ZnPcC4@G3-PAMAM-NH2 materials. It is advantageous to improve the solubility and reduce the aggregation tendency of ZnPcC4 in aqueous solution. The singlet oxygen yield of ZnPcC4@G3-PAMAM-NH2 with different raw ratios of ZnPcC4 to G3-PAMAM-NH2. which was determined by chemiluminescence method, was based on the high sensitive MCLA. The photodynamic activity of ZnPcC4@G3-PAMAM-NH2 by cancer cells Hep-G2 in vitro showed that the activity of photodynamic therapy was associated with the raw ratio of ZnPcC4 to G3-PAMAM-NH2. The ZnPcC4@G3-PAMAM-NH2 system with best photodynamic activity (IC501.67 μg/mL) was found to obtain from 1:0.01 raw ratio of ZnPcC4 to G3-PAMAM-NH2. This result was consistent with the ability of ZnPcC4@G3-PAMAM-NH2 system to produce 1O2 by chemiluminescence method, basing on the MCLA. It could infer that the raw ratio of ZnPcC4 to G3-PAMAM-NH2 of optimizing complex is 6:1 from the mass spectrum.