PHOTOSENSITIZED DESTRUCTION OF HUMAN BLADDER-CARCINOMA CELLS TREATED WITH CHLORIN E6-CONJUGATED MICROSPHERES
PHOTOSENSITIZED DESTRUCTION OF HUMAN BLADDER-CARCINOMA CELLS TREATED WITH CHLORIN E6-CONJUGATED MICROSPHERES
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DOI：
10.1073/pnas.88.4.1580
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发表时间：
1991-02-01
影响因子：
11.1
通讯作者：
HASAN, T
中科院分区：
文献类型：
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作者：
BACHOR, R;SHEA, CR;HASAN, T
研究了1微米直径聚苯乙烯微球共价键合的光敏剂偶联物Ce6对人膀胱癌MGH-U1细胞的光动力杀伤作用。这些微球被癌细胞贪婪地摄取；激光共聚焦扫描荧光显微镜显示它们定位在细胞质中，显然是在溶酶体中，用吖啶橙标记可见。相反，未结合Ce6的荧光存在于大多数细胞膜中。使用Ce6-微球结合物导致细胞内平均浓度比未结合的Ce6高20倍。在Ce6-微球结合物(0.43-mU-M当量)存在下孵育的细胞，然后用氩离子激光泵浦的染料激光在659 nm处照射，显示出剂量依赖性的光毒性，导致在5J/cm2的辐射照射下完全抑制集落形成；相反，在激光照射前，未结合的Ce6(0.43-mU-M)或未结合的微球孵育的细胞不受影响。经Ce6-微球结合物处理的细胞在90%(H2O)-H-2存在的照射下，光毒性显著增加，这一效应与激发态单线态氧在损伤机制中的重要作用相一致。然而，在溶液中，Ce6-微球结合物光敏产生单线态氧的效率比未结合的Ce6低9倍。因此，Ce6-微球结合物的光毒性明显高于未结合的Ce6，这是由于通过吞噬结合物及其特定的细胞内定位位置而获得的较高的Ce6细胞内浓度的结果。因此，这些偶联物是将光敏药物输送到癌细胞的有效系统。
A photosensitizer conjugate, chlorin e6 (Ce6) covalently bound to 1-mu-m-diameter polystyrene microspheres, has been investigated in the photodynamic destruction of MGH-U1 human bladder carcinoma cells in vitro. The microspheres were taken up avidly by the carcinoma cells; confocal laser scanning fluorescence microscopy showed them to be localized in the cytoplasm, apparently within lysosomes, visualized by labeling with acridine orange. In contrast, fluorescence of unconjugated Ce6 was present within most cellular membranes. Use of Ce6-microsphere conjugates led to a 20-fold-higher mean intracellular concentration, compared with unconjugated Ce6. Cells incubated in the presence of Ce6-microsphere conjugates (0.43-mu-M equivalent) and subsequently irradiated at 659 nm with a dye laser pumped by an argon-ion laser showed dose-dependent phototoxicity, leading to total inhibition of colony formation at a radiant exposure of 5 J/cm2; in contrast, cells incubated with either unconjugated Ce6 (0.43-mu-M) or unconjugated microspheres before laser irradiation were unaffected. Cells pretreated with Ce6-microsphere conjugates and irradiated in the presence of 90% (H2O)-H-2 showed significantly increased phototoxicity, an effect consistent with an important role for excited-state singlet oxygen in the mechanism of injury. In solution, however, photosensitized generation of singlet oxygen with Ce6-microsphere conjugates was 9 times less efficient than with unconjugated Ce6. The markedly greater phototoxicity of Ce6-microsphere conjugates compared to unconjugated Ce6 was therefore a consequence of the high intracellular Ce6 concentration attained by phagocytosis of the conjugates and their particular sites of intracellular localization. Thus, these conjugates are an efficient system for the delivery of photosensitizing drugs to carcinoma cells.