| Background and ObjectivePhotodynamic therapy(PDT) shows considerable promise as a new treatment for malignant rumors on the basis of the accumulation of photosensitizer in malignant tissues and a variety of photochemical reactions that cause cell damage and death when the photosensitizer is activated by light at appropriate wavelength. Benzoporphyrin derivative monoacid ring A(BPD-MA) is a new second-generation photosensitizer with properties of ideal photosensitizer such as chemical purity, minimal dark toxicity, significant absorption at longer wavelength, high quarum yields for the generation of type I and II photochemical reactions, preferential tumor localization and rapid clearance from normal tissue. So photodynamic therapy with BPD-MA has become a promising approach to treat patients with skin and intraocular tumors. However, it has not been reported to treat the patients with bladder cancer by photodynamic therapy with BPD-MA, and the photobiological mechanisms of photodynamic therapy with BPD-MA need to be further investigated. The first objective of this study was to establish a light radiation system for the photodynamic study on culture cells and deterimine its major parameters.The second objective was to study the photodynamic inhibitory action on BIU-87 cells with BPD-MA so as to investigate the possibility of BPD-MA-PDT for clinical application to treating the patients with bladder cancer.The third objective was to observe the cell proliferating and metabolic status, PCNA-positive expression, apoptotic status, the alteration of mitochondria and the expressions of bcl-2 and bax proteins in BIU-87 cells post BPD-MA-PDT so as to propose the inhibitory mechanism of photodynamictherapy with BPD-MA on BIU-87. The study will provide a foundation for invivo study and clinical application. Methods and Results1. A light-radiation system established for the photodynamic study on culture cells and its major parameters determined.l)The absorption characteristics of BPD-MA and the transmission of the cell culture materials were investigated by UV-2201 ultraviolet spectrophotometer. The results showed that the absorption peaks of BPD-MA were located at 200-210nm, 360nm, 400~470nm, 580nm, 630~640nm and 690nm, the light at the wavelength of 600-800 nm could easily transmit the culture plate and RPMI1640 medium with 10% PCS, which indicated that the light at the wavelength of 632.8nm could not only activate BPD-MA but also could easily transmit the culture plate and culture medium with 10% PCS. And the transmission of the light at the wavelength of 632.8nm chosen as the light source through the culture plate and culture medium with 10% PCS was 89.97 0.02%,89.12 0.03% respectively .So the light dose on the cell monolayer equalled to 80.18 percent of the light dose of the laser source on the basis of the formula: D1=D0 T1 T2(D1 stands for the light dose on the cell monolayer,Do represents the light dose of Laser source,T1 stands for the transmission of the light through the culture plate,T2 stands for the transmission of the light through culture medium).2). The human bladder cancer cell lines BIU-87 were plated in 24-well dish and grown for 24h in RPMI1640 medium with 10%FCS. The culture medium was replaced with RPMI1640 medium without 10%FCS at the BPD-MA concentrations(1250,625,312.5ng/ml), and then the absorption characteristics of BPD-MA in BIU-87 cells were analyzed by fluorospectrophotometer at 0 , 15th, 30th, 60th , 90th, 120th, 180th minute respectively after coincubation. The results showed that the uptake of BPD-MA in BIU-87 cells was time-dependent and concentration-dependent, the absorption increased along with concentration of BPD-MA and incubation time before incubated for 90 min, but the highest peak at 90th minute post incubationand then became a plateau of the curve.3).BPD-MA with 1250ng/ml was added into cultured BIU-87 cells and incubated for 90 min at 37 癈 with 5%CO2. After incubation, the BPD-MA-containing medium was removed. The cells were washed twice wit...
|
PDF Full Text Request