邻苯二甲酰亚氨基酞菁锌(ZnPcS2P2)的光谱特性

测定和研究光敏剂的光谱特性,可为确定最佳治疗的光源波长提供直接依据,同时也是荧光诊断中选定检测荧光波长的理论依据．本文研究新型光敏剂邻苯二甲酰亚氨基酞菁锌（ZnPcS2P2）的光谱特性,测出ZnPcS2P2在含10%人血清生理盐水的吸收光谱和荧光发射光谱,并与血卟啉衍生物（HpD）进行比较。实验结果表明：在吸收光谱中ZnPcS2P2的最大吸收峰位于670nm,而HpD的最大的吸收峰在405nm处,所以在光动力学治疗中ZnPcS2P2比HpD效果更好。当用波长为632nm的光源激发时,从荧光发射光谱可知,HpD比ZnPcS2P2获得的荧光激发效率高。因此,HpD在光动力学诊断中有更突出的优点。     

三种卟啉类光敏剂的荧光量子产率

实验研究了喜泊分(Hiporfin),血啉甲醚(HMME)和癌光啉(PsD-007)等3种国产卟啉类光敏剂在水溶液中的吸收和荧光光谱特性,并利用对照法首次测定了它们在水溶液中的荧光量子产率.Hiporfin,HMME和PsD-007具有相似的吸收光谱和荧光发射特性,它们的荧光量子产率分别为0.013,0.026和0.020.实验表明光敏剂的荧光量子产率还与溶液中的氧含量有关.实验结果为光动力学诊断中光敏剂的选择,以及相应最佳荧光激发和检测波长的选取提供了理论依据.     

9,10-二氰蒽合成方法的改进

以蒽为原料,经溴化和氰化两步合成了光敏剂9,10-二氰蒽(DCA)。从反应溶剂的选择及提纯方法等方面改进了DCA的合成方法,提高了溴化和氰化反应的收率。结果表明,溴化反应时,控制溴的滴加温度为30℃,收率可达95%;合成DCA时,采用连续抽提法提纯,以DMSO为溶剂,反应中生成的无机盐完全溶解,粗产物不经抽提DCA收率可达74%～75%;而选用N-甲基吡咯烷酮为溶剂,DCA可与溴化铜形成配合物CuBr_2·DCA·CuBr_2,此配合物加热易分解,DCA收率达到93%。     

新型光敏剂BF01光动力治疗人肝癌的实验研究

探讨光敏剂BF01光动力对人肝癌细胞株bel- 7402体外杀伤效应和体内抑瘤效 应及其作用机制。CCK-8法检测同一激光强度不同给药浓度的(0、0.8、3.2 μmol·L－1)BF01光动力(激光剂量2.4 J/cm²,光照时间 :1min/well,激光波长652 nm)处 理下对bel-7402细胞的抑制率和IC50,流式 细 胞术检测bel-7402细胞死亡方式,DAPI染色 观察细胞凋亡特征,光动力后检测bel-7402活性氧、共聚焦显微镜 观察亚细胞定位,建立 裸鼠人肝癌细胞模型,绘制肿瘤生长曲线,观察治疗效果。BF01-PDT治疗组能明显 抑制bel-7402肿瘤细胞增殖,BF01的浓度为6.4 μmol·L－1时,其杀伤率到86%,半数杀伤 浓度IC50 μmol·L－1,检测细 胞死亡方式主要是以晚期凋亡为主,BF01-PDT作用 bel-7402细胞后,经DAPI染色细胞核的形态呈现出凋亡的特征,活 性氧水平随给药浓度 增加而增加,亚细胞定位在线粒体,体内实验表明BF01-PDT可以明显抑制人肝癌肿瘤生长 。光敏剂BF01介导的光动力疗法对人肝癌细胞及小鼠体内肿瘤生长抑制作用明显,光 动力疗法以细胞凋亡为主,其机制可能与光敏剂BF01定位在肿瘤细胞的线粒体,增加 bel-7402细胞中ROS含量有关。     

中药姜黄素的光谱学特性研究

目的:检测中药姜黄素的光谱学特性,为应用中药姜黄素进行光动力治疗提供实验资料。方法:采用紫外分光光度计测定姜黄素的吸收光谱和荧光分光光度计测定姜黄素的激发光谱和荧光发射光谱。结果:姜黄素在200—230nm和400-450nm处各有一吸收峰值,可见光范围内的最大吸收峰值位于425nm。姜黄素的荧光最大激发波长为425nm,最大发射波长为530nm。     

Pheomelanin Effect on UVB Radiation-Induced Oxidation/Nitration of l-Tyrosine

Pheomelanin is a natural yellow-reddish sulfur-containing pigment derived from tyrosinase-catalyzed oxidation of tyrosine in presence of cysteine. Generally, the formation of melanin pigments is a protective response against the damaging effects of UV radiation in skin. However, pheomelanin, like other photosensitizing substances, can trigger, following exposure to UV radiation, photochemical reactions capable of modifying and damaging cellular components. The photoproperties of this natural pigment have been studied by analyzing pheomelanin effect on oxidation/nitration of tyrosine induced by UVB radiation at different pH values and in presence of iron ions. Photoproperties of pheomelanin can be modulated by various experimental conditions, ranging from the photoprotection to the triggering of potentially damaging photochemical reactions. The study of the photomodification of l-Tyrosine in the presence of the natural pigment pheomelanin has a special relevance, since this tyrosine oxidation/nitration pathway can potentially occur in vivo in tissues exposed to sunlight and play a role in the mechanisms of tissue damage induced by UV radiation.     

羧酸稀土复合光敏剂的研制及其在降解地膜中的应用

根据目前已合成的光敏剂对紫外光吸收的波长及吸光系数不同,对光敏剂进行复合,研制出对紫外光具有较高吸收效率的复合光敏剂,并制备了光钙型环境友好降解地膜塑料材料;通过人工加速老化实验、户外曝晒实验,采用紫外光谱、红外光谱、热失重分析等方法,对所研制的复合光敏剂的光敏化效果进行表征,结果表明,所研制的复合光敏剂与单一光敏剂相比,具有良好的紫外光敏化效果,羧酸稀土复合光敏剂又能使塑料在光引发后具有避光继续氧化降解的性能。     

光敏剂在光动力治疗中的应用研究进展

光动力疗法（PDT）以其超高时空分辨率、非侵入性及低毒副作用的优点,被认为是治疗癌症和各种非恶性疾病的有效疗法之一。本文主要综述了几类光敏剂发展历史、主要结构、特点及研究进展,分析了高性能光敏剂的开发动态,包括化学修饰;与具有特定细胞受体的其他配体缀合成复合光敏剂;采取纳米技术,如纳米颗粒输送,基于富勒烯的光敏剂等。基于此,指出具有临床应用前景的高性能光敏剂的基本特征、设计原则及发展趋势。     

Potential Applications of Cucurbit[n]urils Inclusion Complexes in Photodynamic Therapy

Cucurbit[n]urils (CB[n]s) have emerged as potential candidates for drug delivery in several areas due to their strong binding interactions and low toxicity. More recently, their benefits for a type of cancer treatment termed Photodynamic Therapy (PDT) have been recognized. The outcomes of this therapy rely on better drug delivery strategies and improving overall photoactivity of the drugs, which is where CB[n]s could have a strong impact. The effects of these molecular containers on photoactivity are discussed and new interesting work is highlighted.     

In vivo and in vitro evaluation of the cytotoxic effects of Photosan-loaded hollow silica nanoparticles on liver cancer

This study aimed to compare the inhibitory effects of photosensitizers loaded in hollow silica nanoparticles and conventional photosensitizers on HepG2 human hepatoma cell proliferation and determine the underlying mechanisms. Photosensitizers (conventional Photosan-II or nanoscale Photosan-II) were administered to in vitro cultured HepG2 hepatoma cells and treated by photodynamic therapy (PDT) with various levels of light exposure. To assess photosensitizers'' effects, cell viability was determined by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, apoptotic and necrotic cells were measured by flow cytometry and the expression of caspase-3 and caspase-9 evaluated by western blot. Finally, the in vivo effects of nanoscale and conventional photosensitizers on liver cancer were assessed in nude mice. Nanoscale Photosan-II significantly inhibited hepatoma cell viability in a concentration-dependent manner and this effect was more pronounced with high laser doses. Moreover, nanoscale photosensitizers performed better than the conventional ones under the same experimental conditions (p < 0.05). Flow cytometry data demonstrated that laser-induced cell death was markedly increased after treatment with nanoscale Photosan-II in comparison with free Photosan-II (p < 0.05). Activated caspase-3 and caspase-9 levels were significantly higher in cells treated with Photosan-II loaded in silica nanoparticles than free Photosan-II (p < 0.05). Accordingly, treatment with nanoscale photosensitizers resulted in improved outcomes (tumor volume) in a mouse model of liver cancer, in comparison with conventional photosensitizers. Hollow silica nanoparticles containing photosensitizer more efficiently inhibited hepatoma cells than photosensitizer alone, through induction of apoptosis, both in vivo and in vitro.