The Application Of Nano Titanium Dioxide In The Research Of Hypocrellin

Hypocrellin (including hypocrellin A and Hypocrellin B),isolated from theparasitic fungus of Hypocrella bambuase sacc, belongs to 3,10-two hydroxide radical-4,9-chinone derivants. It is an efficient phototherapeutics agent and photosensitizer.Studies indicate Hypocrellin has low toxicity and significant anti-tumor and antiviral activities. More and more people has paied attention to hypocrellin all around the world. It is a very potential natural phototherapeutic drug. In this paper hypocrellin has been investigated in the following respects.1. Because Hypocrellin is an oleophilic compound,one of the difficulties is that it can't afford the double requirer between effective transit in blood and the effective adsorption on cells. In this paper, Hypocrellin encapsulated in titanium dioxide nanoparticles were synthetized with sol-gel method. The average size of the nanoparticles is 120 nm, It can be dissolved in water,phosphate buffered saline,physiological salt solution easily. It can be injected intravenously into the patients and get to the tumor target.2. The spectral properties of Hypocrellin encapsulated in titanium dioxide nanoparticles were studied by IR spectrophotometer, UV/Vis spectrophotometer and spectrofluorimeter and compared with Hypocrellin in water. The results showed that Hypocrellin were encapsulated in titanium dioxide nanoparticles successfully, because of high part concentration, the fluorescence was quenched. The intensity decrease and the peak redshift compared to Hypocrellin in water. After encapsulating, the microenvironment of Hypocrellin was changed and this made the UV/Vis spectrum red shift and intesity increased. All these changes are beneficial to Hypocrellin in phototherapeutics.3. The photostabilities of Hypocrellin encapsulated in titanium dioxide nanoparticles were tested, the results showed that because the protection of titanium dioxide nanoparticles, the photostabilities enhanced. This ensured phototherapeutics drug always possess effective concentration during the whole phototherapy process.4. The quantum yield of singlet oxygen and superoxide anion were tested, all results indicated that the protection of titanium dioxide nanoparticles can reduce the quench chance to active oxygen in water. This indicated that the ability of kill tumor cells has been enhanced.5. The passages size on titanium dioxide nanoparticles were measured by applying a series of quenching agents with different molecule diameters such as KI, diethylamine, triethylamine, quadrol). The results indicated that the passages size on titanium dioxide nanoparticles were between iodide ion and diethylamine.6. The photosensitive damage ability to CT-DNA were tested with spectrofluorimeter, results showed Hypocrellin encapsulated in titanium dioxide nanoparticles has better photosensitive damage ability than that in water.