竹红菌乙素对视网膜和脉络膜光动力学治疗系统生物学效应的评定作用

背景：光动力疗法(photodynamic therapy，PDT)治疗老年性黄斑变性(senile macular degeneration，SMD)的光敏剂苯并卟啉衍生物单酸A环(benzoporphyrin derivative monoacid Aring，BPD-MA)价格昂贵，在国内不能普及。评定国产光敏剂竹红菌乙素(hypocrellin B，HB)对视网膜和脉络膜光动力学治疗系统生物学效应，以探讨是否有价值进一步研究HB治疗SMD的前景。目的：建立视网膜和脉络膜光动力治疗的照射系统、光敏剂体外光敏性检测方法和体内观察光敏剂PDT疗效的方法。设计：开放性实验。地点、材料和干预：实验地点为解放军总医院激光科。建立照射系统：在裂隙灯显微镜开创激光窗口，使用光纤连接激光器和裂隙灯显微镜，使激光和裂隙灯照明同光路到达眼底，作为照射系统；通过四甲偶氮唑盐法检测光敏剂体外光敏性，和BPD-MA相比，初步判断其光敏性。以青紫蓝兔为实验对象，用光敏剂HB进行PDT治疗，通过眼底观察、荧光眼底造影、光镜和电镜检查照光部位的生物学效应，检测建立的实验系统的实用性和可靠性。主要观察指标：裂隙灯显微镜和激光器的耦合效率，光敏剂体外光敏性以及照光部位的生物学效应。结果：照射系统输出稳定，由激光器发出的功率和裂隙灯显微镜的激光窗口末端的输出的功率的耦合率为60％。国产：HB体外光敏性和BPD-MA相似，HB-PDT引起脉络膜毛细血管损伤而对周围正常组织损伤小，达到选择性治疗目的，有进一步研究价值。结论：建立的照射系统和光敏剂光敏性体外评价系统，以及体内观察生物学效应的方法，可作为明确一种光敏剂是否适合治疗视网膜或脉络膜新生血管的初步判定方法。     

竹红菌乙素—光动力疗法对脉络膜毛细血管影响的生物学特征

背景：作者前期实验证实国产光敏剂竹红菌乙素(HB)—光动力疗法可引起脉络膜毛细血管的选择性损伤。改变治疗参数进行HB对脉络膜毛细血管1个月内光动力效应的观察，是否会产生新的结果。目的：观察竹红菌乙素-光动力治疗(HB—PDT)对青紫蓝兔脉络膜毛细血管的生物学效应的特点．探讨HB—PDT治疗脉络膜新生血管以及绿光作为PDT治疗光源的研究前景。设计：单一样本研究。单位：解放军总医院激光科。材料：实验于2002—01／2002—11在解放军总医院激光科、病理科及北京理工大学光电工程系完成光敏利HB，绿激光器、荧光眼底照相机和透射电子显微镜。方法：使用光纤连接532mn激光器和裂隙灯显微镜，选用青紫兰兔2．5～3．5kg，全麻生效后，耳缘静脉内注射HB1．0mg／kg，532nm光线作为光源激发光敏剂，眼底光斑功率密度300mW／cm^2，能量密度30J／cm^2，注射药物后立刻照光，光斑直径2000μm，3例，于PDT后1．7，28d观察视网膜，荧光眼底造影、光学显微镜和电子显微镜观察照光部位视网膜和脉络膜的生物学效应。主要观察指标：直接眼底观察视网膜的非选择性损伤，荧光眼底造影观察脉络膜血管系统的闭塞情况，光学显微镜初步观察视网膜非选择性损伤的部位和程度和脉络膜的血管结构改变，电子显微镜观察眼底组织改变的超微结构的变化。结果：PDT后1d，照光区域脉络膜毛细血管管腔内形成光动力血栓．视网膜的损伤以外层为主，内层没有明显改变第7天脉络膜毛细血管内皮细胞损伤加重，脉络膜大血管无明显改变，第28天后在原来毛细血管的部位出现纤维组织，玻璃膜增厚；照光K域的RPE细胞出现修复、增殖。结论：PDT后第1天至第7天靶组织的生物学效应和非靶组织的非选择性开始出现并不断增强，第28天后逐渐以纤维组织恢复HB—PDT治疗老年性黄斑变性或其他以脉络膜新生血管为特点的眼底疾病，有进一步研究价值。     

竹红菌乙素-光动力疗法对脉络膜毛细血管影响的生物学特征

背景作者前期实验证实国产光敏剂竹红菌乙素(HB)-光动力疗法可引起脉络膜毛细血管的选择性损伤.改变治疗参数进行HB对咏络膜毛细血管1个月内光动力效应的观察,是否会产生新的结果?目的观察竹红菌乙素-光动力治疗(HB-PDT)对青紫蓝兔脉络膜毛细血管的生物学效应的特点,探讨HB-PDT治疗脉络膜新生血管以及绿光作为PDT治疗光源的研究前景.设计单一样本研究.单位解放军总医院激光科.材料实验于2002-01/2002-11在解放军总医院激光科、病理科及北京理工大学光电工程系完成.光敏剂HB,绿激光器、荧光眼底照相机和透射电子显微镜.方法使用光纤连接532 nm激光器和裂隙灯显微镜,选用青紫兰兔2 5～3.5kg,全麻生效后,耳缘静脉内注射HB 1.0mg/kg,532 nm光线作为光源激发光敏剂,眼底光斑功率密度300 mW/cm2,能量密度30 J/cm2,注射药物后立刻照光,光斑直径2000μm,3例,于PDT后1,7,28 d观察视网膜,荧光眼底造影、光学显微镜和电子显微镜观察照光部位视网膜和脉络膜的生物学效应.主要观察指标直接眼底观察视网膜的非选择性损伤,荧光眼底造影观察脉络膜血管系统的闭塞情况,光学显微镜初步观察视网膜非选择性损伤的部位和程度和脉络膜的血管结构改变,电子显微镜观察眼底组织改变的超微结构的变化.结果PDT后1 d,照光区域脉络膜毛细血管管腔内形成光动力血栓,视网膜的损伤以外层为主,内层没有明显改变.第7天脉络膜毛细血管内皮细胞损伤加重,脉络膜大血管无明显改变,第28天后在原来毛细血管的部位出现纤维组织,玻璃膜增厚;照光区域的RPE细胞出现修复、增殖.结论PDT后第1天至第7天靶组织的生物学效应和非靶组织的非选择性开始出现并不断增强,第28天后逐渐以纤维组织恢复.HB-PDT治疗老年性黄斑变性或其他以脉络膜新生血管为特点的眼底疾病,有进一步研究价值.     

不同参数竹红菌乙素-光动力治疗对兔脉络膜毛细血管层的生物学效应

背景世界各国都在进行光敏剂开发,治疗脉络膜新生血管(CNV)疾病的工作,本实验是国内少数几家利用国产光敏剂治疗CNV之一.目的观察不同治疗参数竹红菌乙素-光动力治疗(HB-PDT)对青紫蓝兔脉络膜毛细血管层生物学效应以及对视网膜的非选择性损伤,选择适宜PDT治疗方案,为进一步探讨HB-PDT治疗CNV提供先期研究工作.设计随机对照的实验研究.地点和材料实验在北京解放军总医院和北京理工大学完成,以青紫兰兔为实验材料.干预使用光纤连接532nm激光器和裂隙灯显微镜,作为照射系统.青紫兰兔耳缘静脉内注射竹红菌乙素,532 nm光线激发光敏剂.使用不同PDT方案进行实验,每组实验眼3例,同时以单纯照光组和单照药物组作为对照.主要观察指标PDT后第1天行视网膜观察、荧光眼底造影和组织学检查,观察照光部位及其表面正常组织的变化.结果在PDT后第1天,单纯照光组和单纯药物对照组眼底和组织学无改变;在HB剂量为1.0mg/kg,532 nm连续激光激发光敏剂,功率密度120～700 mW/cm2,能量密度14.4～60 J/cm2,可以导致脉络膜毛细血管层的闭塞,对视网膜外层有损害,内层无明显改变.HB剂量1.0 mg/kg,功率密度300～600 mW/cm2,照光时间100～80 s,能量密度30～50 J/cm2是适宜的治疗方案.结论HB对视网膜和脉络膜的生物学效应与光敏剂的剂量、照光时机、功率密度、能量密度密切相关.生物学效应与能量密度呈量效依赖性关系.     

不同参数竹红菌乙素-光动力治疗对兔脉络膜毛细血管层的生物学效应

背景：世界各国都在进行光敏剂开发，治疗脉络膜新生血管(CNV)疾病的工作，本实验是国内少数几家利用国产光敏剂治疗CNV之一。目的：观察不同治疗参数竹红菌乙素一光动力治疗(HB-PDT)对青紫蓝兔脉络膜毛细血管层生物学效应以及对视网膜的非选择性损伤，选择适宜PDT治疗方案，为进一步探讨HB-PDT治疗CNV提供先期研究工作。设计：随机对照的实验研究。地点和材料：实验在北京解放军总医院和北京理工大学完成，以青紫兰兔为实验材料。干预：使用光纤连接532nm激光器和裂隙灯显微镜，作为照射系统。青紫兰兔耳缘静脉内注射竹红菌乙素，532nm光线激发光敏剂。使用不同PDT方案进行实验，每组实验眼3例，同时以单纯照光组和单照药物组作为对照。主要观察指标：PDT后第1天行视网膜观察、荧光眼底造影和组织学检查，观察照光部位及其表面正常组织的变化。结果：在PDT后第1天，单纯照光组和单纯药物对照组眼底和组织学无改变；在HB剂量为1．0mg／kg，532nm连续激光激发光敏剂，功率密度120～700mW／cm^2，能量密度14．4～60J／cm^2，可以导致脉络膜毛细血管层的闭塞，对视网膜外层有损害，内层无明显改变。HB剂量1．0mg／kg，功率密度300～600mW／cm^2，照光时间100～80s，能量密度30～50J／cm^2是适宜的治疗方案。结论：HB对视网膜和脉络膜的生物学效应与光敏剂的剂量、照光时机、功率密度、能量密度密切相关。生物学效应与能量密度呈量效依赖性关系。     

光动力疗法治疗脉络膜新生血管的护理

脉络膜新生血管（GNU）是异常的新生血管在视网膜下,特别是黄斑部的视网膜下生长,引起视网膜出血、水肿及视网膜组织的破坏,最终形成疤痕,导致中心视力丧失,是全球成年人致盲的首要疾病之一,常见于年龄相关性黄斑变性（AMD）、病理性近视（PM）等眼底疾病,主要的治疗方法是光动力疗法（PDT）。光动力疗法（PDT）是指将一种特殊的光敏剂通过静脉推注,到达病变组织后,利用激光照射,将靶组织的光敏剂激活,产生光化学效应,以达到治疗目的的一种新方法。本院于2008年开展此新技术。现将护理体会报告如下。     

1例老年直肠癌患者行光动力治疗的观察与护理

光动力疗法(photon dynamic treatment,PDT)又称光敏疗法、光化学疗法,它是现代肿瘤微创或无创领域的最新进展,原理是肿瘤摄取预先注射的光敏剂后,在体外导入激光的照射下肿瘤组织产生单碳氧,使肿瘤细胞变性坏死,以达到治疗的一种方法[1].     

眼科光动力疗法围术期病人的心理特征及对策

光动力疗法(photodynamic therapy,PDT)是利用光敏剂选择性地在新生血管等增生活跃的组织中聚集、滞留的特性,在相应波长的光照射下产生化学效应,破坏病变组织从而达到治疗目的的治疗方法。目前PDT被广泛地应用于眼科脉络膜新生血管相关性疾病的治疗。PDT疗法的围术期包括了治疗前、治     

1例老年直肠癌患者行光动力治疗的观察与护理

光动力疗法(photon dynamic treat ment,PDT)又称光敏疗法、光化学疗法,它是现代肿瘤微创或无创领域的最新进展,原理是肿瘤摄取预先注射的光敏剂后,在体外导入激光的照射下肿瘤组织产生单碳氧,使肿瘤细胞变性坏死,以达到治疗的一种方法[1]。该疗法对体表肿瘤、消化道肿瘤、肝癌     

光动力疗法治疗脉络膜新生血管致视力下降病人的护理

脉络膜新生血管(CNV)可导致视力重度下降,从而影响病人的生活质量.光动力疗法(photodynamic therapy,PDT)可有效降低中度到重度视力丧失的危险,PDT治疗是将特异的光敏剂维替泊芬注入血管中,随血流到达眼底异常的新生血管,然后用一种特殊的非热能激光(冷激光)照射,从而破坏异常的新生血管,抑制各种新生血管的发展,从而保存视力的一种疗法.     

Intracellular target for photosensitization in cancer antiangiogenic photodynamic therapy mediated by polycation liposome.

Previous study indicated that antiangiogenic photodynamic therapy (PDT), laser irradiation at 15 min post-injection of photosensitizer in vivo, is effective for cancer treatment, and a photosensitizer, benzoporphyrin derivative monoacid ring A (BPD-MA), encapsulated in polycation liposomes (PCLs), liposomes modified with cetylated polyethylenimine (cetyl-PEI), is more effective than BPD-MA encapsulated in non-modified liposomes [Cancer 97 (2003) 2027]. In the present study, we examined intracellular distribution of BPD-MA. BPD-MA encapsulated in liposomes or in PCLs was incubated with human endothelial cell line ECV304 cells or human umbilical vein endothelial cells (HUVECs), and monitored the intracellular distribution of BPD-MA by confocal laser scan microscopy. BPD-MA was taken up time-dependently into the cells and was distributed in not only cytoplasmic area but also intranuclear region. The enhanced uptake of BPD-MA was observed by the PCL formulation. Intracellular distribution of polycation was monitored by using fluorescein isothiocyanate-labeled cetyl-PEI (cetyl-PEI-FITC) and was colocalized with BPD-MA. Cytoplasmic BPD-MA distribution was partly overlapped with that of rhodamine 123, a mitochondrial fluorostaining probe, suggesting that mitochondrial photosensitization as well as nuclear photosensitization, is involved in the antiangiogenic PDT treatment.     

竹红菌甲素脂质体对体外培养肿瘤HeLa细胞的光灭活作用

目的 本研究旨在观察及探讨竹红菌甲素(HA)脂质体对体外培养肿瘤细胞的光动力作用.方法 构建HA脂质体,注入体外培养瘤细胞的培养基中,并用新鲜Hank′s液反复冲洗后,于室温下在碘钨灯下照光,通过与单纯照光组、单用HA脂质体组、空白对照组对比的实验方法,观察HA脂质体对体外培养瘤细胞的光动力学作用.结果 注有HA脂质体的培养基中经光照显示HeLa细胞的不同时间段的死亡率比单纯照光组及单用HA脂质体组均高(P<0.05).结论 HA脂质体对培养基中HeLa细胞光动力灭活作用确切.HA结构单一清楚,光动力作用确切可靠,也应是一种具有发展前途的光敏剂.     

Cellular distribution and phototoxicity of Benzoporphyrin derivative and Photofrin

Photodynamic therapy (PDT) induces cell-membrane damage and alterations in cancer-cell adhesiveness, an important parameter in cancer metastasis. These alterations result from cell sensitivity to photosensitizers and the distribution of photosensitizers in cells. The efficacy of photosensitizers depends on their close proximity to targets and thus on their pharmacokinetics at the cellular level. We studied the cellular distribution of photosensitizers with a confocal microspectrofluorimeter by analysing the fluorescence emitted by benzoporphyrin derivative-monoacid ring A (BPD-MA) and Photofrin relative to their cell sensitivity. Two cancer cell lines of colonic origin, but with different metastatic properties, were used: PROb (progressive) and REGb (regressive). For BPD-MA (1.75 μg/ml), maximal fluorescence intensity (8,300 cts) was reached after 2 h for PROb and after 1 h (4,900 cts) for REGb. For Photofrin (10 μg/ml), maximal fluorescence intensity (467 cts) was reached after 5 h for PROb and after 3 h (404 cts) for REGb. Intracellular studies revealed stronger cytoplasmic than nuclear fluorescence for both BPD and Photofrin. Both of the sensitizers induced a dose-dependent photo-toxicity; LD₅₀ with BPD-MA was 93.3 ng/ml for PROb and 71.1 ng/ml for REGb, under an irradiation of 10 J/cm². With Photofrin, LD₅₀ was 1,270 ng/ml for PROb and 1,200 ng/ml for REGb under an irradiation of 25 J/cm². The photosensitizer effect within PROb and REGb cancer cells was assessed by incorporation kinetics and toxicity-phototoxicity tests. The intracellular concentration of the photosensitive agent was one important factor in the effectiveness of PDT, but not the only one contributing to the photodynamic effect. In conclusion, this study showed that there was a clear difference between sensitizer uptake and phototoxicity, even in cancer cells of the same origin. This could induce cell-killing heterogeneity in clinics.     

Cooperative Clinical Trial of Photodynamic Therapy for Early Gastric Cancer With Photofrin Injection and YAG-OPO Laser

Background and Objective: Photodynamic therapy (PDT) treats malignant tumors using photosensitizers and light. We employed a new pulse laser as the excitation light source for PDT, i.e. an optical parametric oscillator (OPO) system pumped by a Q-switched Nd:YAG laser, because it provides extremely high peak power.Study Design/Materials and Methods: The effects of PDT using the photosensitizer Photofrin((R)) and the new laser were evaluated in 12 patients with early gastric cancer.Results: Complete responses (CR) were obtained in 75% of 12 assessable patients, CR was observed in all cases with mucosal carcinoma (response rate 100%).Regarding toxicity, mild photosensitivity was seen in one case and it lasted several weeks. The other major side effect was decrease of total protein, which was observed in six patients (40%), lasting several months. There were no serious abnormalities in symptoms or laboratory tests.Conclusion: We conclude that the YAG-OPO laser is suitable as an excitation light source for PDT.     

Cellular distribution and phototoxicity of Benzoporphyrin derivative and Photofrin

Photodynamic therapy (PDT) induces cell-membrane damage and alterations in cancer-cell adhesiveness, an important parameter in cancer metastasis. These alterations result from cell sensitivity to photosensitizers and the distribution of photosensitizers in cells. The efficacy of photosensitizers depends on their close proximity to targets and thus on their pharmacokinetics at the cellular level. We studied the cellular distribution of photosensitizers with a confocal microspectrofluorimeter by analysing the fluorescence emitted by benzoporphyrin derivative-monoacid ring A (BPD-MA) and Photofrin relative to their cell sensitivity. Two cancer cell lines of colonic origin, but with different metastatic properties, were used: PROb (progressive) and REGb (regressive). For BPD-MA (1.75 µg/ml), maximal fluorescence intensity (8,300 cts) was reached after 2 h for PROb and after 1 h (4,900 cts) for REGb. For Photofrin (10 µg/ml), maximal fluorescence intensity (467 cts) was reached after 5 h for PROb and after 3 h (404 cts) for REGb. Intracellular studies revealed stronger cytoplasmic than nuclear fluorescence for both BPD and Photofrin. Both of the sensitizers induced a dose-dependent phototoxicity; LD₅₀ with BPD-MA was 93.3 ng/ml for PROb and 71.1 ng/ml for REGb, under an irradiation of 10 J/cm². With Photofrin, LD₅₀ was 1,270 ng/ml for PROb and 1,200 ng/ml for REGb under an irradiation of 25 J/cm². The photosensitizer effect within PROb and REGb cancer cells was assessed by incorporation kinetics and toxicity-phototoxicity tests. The intracellular concentration of the photosensitive agent was one important factor in the effectiveness of PDT, but not the only one contributing to the photodynamic effect. In conclusion, this study showed that there was a clear difference between sensitizer uptake and phototoxicity, even in cancer cells of the same origin. This could induce cell-killing heterogeneity in clinics.     

Photodynamic therapy

Photodynamic therapy (PDT) is a photochemical process that uses?a photosensitizer drug activated by laser light to produce mucosal ablation. Porfimer sodium PDT has proved long-term efficacy and durability in the treatment of Barrett's esophagus and high-grade dysplasia and early esophageal adenocarcinoma. Its use has been limited by serious side effects including prolonged cutaneous photosensitivity and stricture formation. Other photosensitizers with a better safety profile have been used mostly in Europe with limited experience. The future of PDT lies on a better understanding of dosimetry, tissue properties, and host genetic factors.     

Development of a model to demonstrate photosensitizer-mediated viral inactivation in blood

A model has been developed to demonstrate the use of photodynamic treatment (PDT) to eradicate viral contaminants from donated blood and blood products. Whole blood, spiked with vesicular stomatitis virus (VSV), was treated with the photosensitizer benzoporphyrin derivative-monoacid ring A (BPD-MA). After light activation of BPD-MA, a neutral red dye uptake assay was carried out to determine virus inactivation. Various drug incubation times and light intensities were tested as well as red cell lysis and distribution of VSV in blood. At BPD-MA concentrations between 2 and 4 micrograms per mL in whole blood, up to 10(7) VSV were inactivated. Several photosensitizers were also tested with this model to determine their relative efficacy in viral inactivation.     

Erythrosine is a potential photosensitizer for the photodynamic therapy of oral plaque biofilms

OBJECTIVES: The purpose of this study was to evaluate the clinical plaque disclosing agent erythrosine as a photosensitizer in the photodynamic killing of the oral bacterium Streptococcus mutans grown as a biofilm. METHODS: S. mutans biofilms of 200 microm thickness were grown in a constant-depth film fermenter. In addition to determining localization of the photosensitizer within biofilms using confocal laser scanning microscopy (CLSM), we compared the bacterial killing efficacy of erythrosine with that of two well-characterized photosensitizers, methylene blue (MB) and photofrin. Incubations were carried out with each photosensitizer (22 microM), and irradiation was for 15 min using a 400 W white light source. RESULTS: The CLSM results showed that erythrosine is taken up into S. mutans biofilms, where it is associated with the biomass of the biofilm rather than the fluid-filled channels and voids. Comparison of the cell killing efficacy of erythrosine in S. mutans biofilms of different ages showed that erythrosine was 1-2 log(10) more effective at killing biofilm bacteria than photofrin and 0.5-1 log(10) more effective than MB. The results were statistically significant (P < 0.01). Photodynamic therapy (PDT) with all three photosensitizers was increasingly effective as biofilm age increased, suggesting that temporal changes in biofilm architecture and composition affect susceptibility to PDT. CONCLUSIONS: PDT using erythrosine as photosensitizer shows excellent potential as a treatment for oral plaque biofilms.