叶绿素类光敏剂在光动力抗肿瘤中的研究进展

光动力疗法（PDT）是一种多学科交叉融合发展起来的肿瘤治疗方法,光敏剂（PS）是光动力疗法中的重要作用因素。其中,叶绿素类光敏剂包含叶绿素及其衍生物,具有优良的光物理性质,是一类很有临床应用前景的光敏剂,目前针对叶绿素类光敏剂的基础研究及临床应用研究也正在开展。本文拟就八大叶绿素类光敏剂的特征、临床应用及研究进展进行综述。     

光动力疗法及光动力治疗研究应用

随着光动力的研究、光敏剂和光源的不断发展,光动力治疗在肿瘤治疗中的应用已日趋成熟。光动力疗法的基础与理论研究,以及新产品的不断上市,也给患者带来了福音。笔者总结今年光动力基础研究和临床研究,并阐述相关观点。     

光动力学疗法中光敏剂的研究和展望

光动力学疗法(photodynamic therapy,PDT)是一种独具特点的肿瘤治疗新技术,它是随着光敏剂的发现、发展而逐渐建立和完善的。第1代光敏剂血卟啉衍生物的出现奠定了光动力学疗法临床应用的基础。近年来,多种第2代光敏剂不断涌现,丰富了临床用药的选择,进一步扩展了适应症。国内光动力研究经历一段时间低迷后,也有新型光敏剂进入临床研究,预期国内会再次出现一个光敏剂研究和应用的高潮。本文对目前临床研究的主要光敏剂作一回顾分析和总结,并对未来光敏剂的研究方向进行展望。     

Mitochondrial dysfunction is related to necrosis-like programmed cell death induced by A23187 in CEM cells

We have previously reported that calcium ionophore A23187 differentially induces necrosis in CEM cells, a T-lymphoblastic leukemia cell line, and apoptosis in HL60 cells, a promyelocytic leukemia cell line. Stimulation with VP16, however, induces typical apoptosis in both cell lines. Necrosis in CEM cells, characterized by cell shrinkage and clustering, began within 5 min of treatment. Swelling of the mitochondria, lumpy chromatin condensation and intact plasma membranes were evident by electron microscopy. These A23187-mediated changes in CEM cells were suppressed by clonazepam or CGP37157, inhibitors of the mitochondrial Na(+)/Ca(2+) exchanger. The changes, however, were not affected by cyclosporin A, an inhibitor of the mitochondrial permeability transition pore. In both CEM and HL60 cells, intra-cellular calcium increased with similar amplitude within 1 min of treatment with 2 microM A23187. Intra-mitochondrial calcium increased with clonazepam pre-treatment alone in both CEM and HL60 cells. However, intra-mitochondrial calcium did not change drastically in response to A23187 in CEM or HL60 cells, either untreated or pre-treated with clonazepam. A23187 induces necrosis in CEM cells concurrent with mitochondrial dysfunction, which is independent of the mitochondrial permeability transition, but affected by intra-mitochondrial calcium, while HL60 cells lack these early changes. Differences in the responses to A23187 between these two cell lines might derive from differences in the susceptibility of the mitochondrial membrane to rapid increases in intra-cellular calcium.     

Nanoparticles in photodynamic therapy: an emerging paradigm

Photodynamic therapy (PDT) has emerged as one of the important therapeutic options in management of cancer and other diseases [M. Triesscheijn, P. Baas, J.H. Schellens, F.A. Stewart, Photodynamic therapy in oncology, Oncologist 11 (2006) 1034-1044]. Most photosensitizers are highly hydrophobic and require delivery systems. Previous classification of delivery systems was based on presence or absence of a targeting molecule on the surface [Y.N. Konan, R. Gurny, E. Allemann, State of the art in the delivery of photosensitizers for photodynamic therapy, J. Photochem. Photobiol., B 66 (2002) 89-106]. Recent reports have described carrier nanoparticles with additional active complementary and supplementary roles in PDT. We introduce a functional classification for nanoparticles in PDT to divide them into passive carriers and active participants in photosensitizer excitation. Active nanoparticles are distinguished from non-biodegradable carriers with extraneous functions, and sub-classified mechanistically into photosensitizer nanoparticles, [A.C. Samia, X. Chen, C. Burda, Semiconductor quantum dots for photodynamic therapy, J. Am. Chem. Soc. 125 (2003) 15736-15737, R. Bakalova, H. Ohba, Z. Zhelev, M. Ishikawa, Y. Baba, Quantum dots as photosensitizers? Nat. Biotechnol. 22 (2004) 1360-1361] self-illuminating nanoparticles [W. Chen, J. Zhang, Using nanoparticles to enable simultaneous radiation and photodynamic therapies for cancer treatment, J. Nanosci. Nanotechnology 6 (2006) 1159-1166] and upconverting nanoparticles [P. Zhang, W. Steelant, M. Kumar, M. Scholfield, Versatile photosensitizers for photodynamic therapy at infrared excitation, J. Am. Chem. Soc. 129 (2007) 4526-4527]. Although several challenges remain before they can be adopted for clinical use, these active or second-generation PDT nanoparticles probably offer the best hope for extending the reach of PDT to regions deep in the body.     

Nanoparticle-mediated combination chemotherapy and photodynamic therapy overcomes tumor drug resistance in vitro

Drug resistance limits the success of many anticancer drugs. Reduced accumulation of the drug at its intracellular site of action because of overexpression of efflux transporters such as P-glycoprotein (P-gp) is a major mechanism of drug resistance. In this study, we investigated whether photodynamic therapy (PDT) using methylene blue, also a P-gp inhibitor, can be used to enhance doxorubicin-induced cytotoxicity in drug-resistant tumor cells. Aerosol OT (AOT)-alginate nanoparticles were used as a carrier for the simultaneous cellular delivery of doxorubicin and methylene blue. Methylene blue was photoactivated using light of 665 nm wavelength. Induction of apoptosis and necrosis following treatment with combination chemotherapy and PDT was investigated in drug-resistant NCI/ADR-RES cells using flow cytometry and fluorescence microscopy. Effect of encapsulation in nanoparticles on the intracellular accumulation of doxorubicin and methylene blue was investigated qualitatively using fluorescence microscopy and was quantitated using HPLC. Encapsulation in AOT-alginate nanoparticles significantly enhanced the cytotoxicity of combination therapy in resistant tumor cells. Nanoparticle-mediated combination therapy resulted in a significant induction of both apoptosis and necrosis. Improvement in cytotoxicity could be correlated with enhanced intracellular and nuclear delivery of the two drugs. Further, nanoparticle-mediated combination therapy resulted in significantly elevated reactive oxygen species (ROS) production compared to single drug treatment. In conclusion, nanoparticle-mediated combination chemotherapy and PDT using doxorubicin and methylene blue was able to overcome resistance mechanisms and resulted in improved cytotoxicity in drug-resistant tumor cells.     

抗真菌的化学治疗与光动力学治疗药物的研究进展

随着免疫缺陷患者增多、器官移植和环境的日益恶化,真菌病的发生率正逐年上升,真菌的耐药性也日益严重,研究新型抗真菌药物和新的治疗途径已成为国内外研究的热点。对于真菌病的治疗,化学治疗是目前临床上的主要手段,而光动力治疗是新兴的方法。本文将从抗真菌的化学治疗药物和光动力治疗药物两个方面分析和总结抗真菌药物的研究现状和发展前景。     

The p53-mediated cytotoxicity of photodynamic therapy of cancer: recent advances

Photodynamic therapy (PDT) is a promising modality for the treatment of both pre-malignant and malignant lesions. The mechanism of action converges mainly on the generation of reactive oxygen species which damage cancer cells directly as well as indirectly acting on tumor vasculature. The exact mechanism of PDT action is not fully understood, which is a formidable barrier to its successful clinical application. Elucidation of the mechanisms of cancer cell elimination by PDT might help in establishing highly specific, non-genotoxic anti-cancer treatment of tomorrow. One of the candidate PDT targets is the well-known tumor suppressor p53 protein recognized as the guardian of the genome. Together with its family members, p73 and p63 proteins, p53 is involved in apoptosis induction upon stress stimuli. The wild-type and mutant p53-targeting chemotherapeutics are currently extensively investigated as a promising strategy for highly specific anti-cancer therapy. In photodynamic therapy porphyrinogenic sensitizers are the most widely used compounds due to their potent biophysical and biochemical properties. Recent data suggest that the p53 tumor suppressor protein might play a significant role in porphyrin-PDT-mediated cell death by direct interaction with the drug which leads to its accumulation and induction of p53-dependent cell death both in the dark and upon irradiation. In this review we describe the available evidence on the role of p53 in PDT.     

One-pot preparation of nanodispersion with readily available components for localized tumor photothermal and photodynamic therapy

Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparation procedures. To actualize a high-efficiency combination therapy for cancer via a feasible approach, three readily available materials are simply associated together in one-pot, namely the single-walled carbon nanohorns(SWCNH), zinc phthalocyanine(ZnPc), and surfactant TPGS. The es...     

光动力学在中重度痤疮治疗中的疗效观察

目的 对中重度痤疮采用光动力学治疗的临床疗效予以分析.方法 86例中重度痤疮患者,按照随机数字表法分为对照组和观察组,每组43例.观察组实施氨基酮戊酸光动力学治疗,对照组予以红蓝光治疗.比较两组患者临床疗效,治疗8周后残留皮损数,治疗前后肿瘤坏死因子-α与白细胞介素-8水平,并发症(红斑水肿、皮肤瘙痒、皮肤干涩)发生情...     

微创结合光动力治疗中重度痤疮的临床观察和护理

目的 观察微创结合光动力治疗中重度痤疮的临床效果.方法 收集来本院皮肤科门诊就诊的中重度痤疮患者60例,采用随机数字表法将其分为观察组与对照组,各30例.观察组采用微创结合光动力疗法进行治疗,对照组使用光动力疗法进行治疗,两组患者治疗前和治疗后痤疮皮损面积和严重程度指数评分、治疗后的临床疗效以及不良反应发生率进行比较.结果 治疗后两组患者的粉刺、丘疹、脓疱和结节、囊肿个数以及GAGS评分均低于治疗前,且治疗后观察组的粉刺、丘疹、脓疱和结节、囊肿个数以及GAGS评分均低于对照组,差异有统计学意义(P＜0.05);观察组总有效率为93.3％,对照组总有效率为63.3％,差异有统计学意义(P＜0.05);两组患者在红斑、肿胀疼痛、反应性痤疮、色素沉着和面部瘙痒方面的不良反应发生率比较,差异无统计学意义(P＞0.05),而对照组的脱屑反应发生率高于观察组,差异有统计学意义(P＜0.05).结论 微创结合光动力治疗中重度痤疮的疗法简单、安全、有效,推荐在临床上应用.     

5-氨基酮戊酸光动力疗法联合电灼术治疗肛周尖锐湿疣疗效观察

目的 评价5-氨基酮戊酸光动力疗法（ALA-PDT）联合电灼术治疗肛周尖锐湿疣的疗效和复发率.方法 将67例肛周尖锐湿疣患者按门诊就诊顺序随机分为三组,联合治疗组22例用电灼术去除显性疣体后立即进行ALA-PDT治疗,每周1次,连续治疗3～4次;光动力组22例,用ALA-PDT治疗,每周1次,1个月为1个疗程;电灼术组23例,用传统方法电灼术对所有皮损逐个进行电灼气化治疗,每周1次的分批治疗,1个月为1个疗程.末次治疗后随访6个月判定疗效及观察复发率.结果 联合治疗组痊愈率为90.9％（20/22）,复发率为9.1％ （2/22）;光动力组痊愈率为54.5％ （12/22）,复发率为22.7％ （5/22）;电灼术组痊愈率为39.1％ （9/23）,复发率为43.5％ （10/23）.联合治疗组的痊愈率和复发率与电灼术治疗组差异有统计学意义（P =0.000;P =0.017）.结论 ALA-PDT治疗肛周尖锐湿疣治愈率高,复发率低,副作用小.     

光动力疗法联合紫杉醇对结直肠癌患者淋巴细胞转移增殖的影响

目的探讨光动力疗法联合紫杉醇对结直肠癌患者淋巴细胞转移增殖的影响。方法连续选取我院2013年1月至2014年1月收治的结直肠癌患者40例,随机分为对照组和试验组,每组20例。对照组给予单纯的紫杉醇化疗,根据癌症的分级、分期情况合理选择化疗疗程;试验组联合应用光动力疗法和紫杉醇。对比分析两组患者的T淋巴细胞转移率、淋巴细胞凋亡率、IFN-γ增殖水平以及淋巴细胞IL-2表达水平和临床有效率的差异性,同时对两组治疗前后的E-cadherin病理表达情况进行分析。结果试验组患者的T淋巴细胞转移率高于对照组,淋巴细胞凋亡率低于对照组,IFN-γ和IL-2的表达水平高于对照组,差异均有统计学意义(P<0.05)。试验组患者的总有效率高于对照组,生存时间较对照组延长,住院时间较对照组缩短,差异均有统计学意义(P<0.05)。治疗前,试验组与对照组的E-cadherin阳性表达率分别为10.0%、15.0%,治疗后分别为25.0%和60.0%,两组比较差异有统计学意义(P<0.05)。结论光动力疗法联合紫杉醇治疗结直肠癌能较好地抑制患者淋巴细胞的转移和增殖情况,增强E-cadherin表达,提高有效率。     

Enhanced photodynamic efficacy towards melanoma cells by encapsulation of Pc4 in silica nanoparticles

Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore limits its clinical application. We have encapsulated Pc4 using silica nanoparticles (Pc4SNP), which not only improved the aqueous solubility, stability, and delivery of the photodynamic drug but also increased its photodynamic efficacy compared to free Pc4 molecules. Pc4SNP generated photo-induced singlet oxygen more efficiently than free Pc4 as measured by chemical probe and EPR trapping techniques. Transmission electron microscopy and dynamic light scattering measurements showed that the size of the particles is in the range of 25–30 nm. Cell viability measurements demonstrated that Pc4SNP was more phototoxic to A375 or B16-F10 melanoma cells than free Pc4. Pc4SNP photodamaged melanoma cells primarily through apoptosis. Irradiation of A375 cells in the presence of Pc4SNP resulted in a significant increase in intracellular protein-derived peroxides, suggesting a Type II (singlet oxygen) mechanism for phototoxicity. More Pc4SNP than free Pc4 was localized in the mitochondria and lysosomes. Our results show that these stable, monodispersed silica nanoparticles may be an effective new formulation for Pc4 in its preclinical and clinical studies. We expect that modifying the surface of silicon nanoparticles encapsulating the photosensitizers with antibodies specific to melanoma cells will lead to even better early diagnosis and targeted treatment of melanoma in the future.     

GSH-sensitive polymeric prodrug: Synthesis and loading with photosensitizers as nanoscale chemo-photodynamic anti-cancer nanomedicine

Precisely delivering combinational therapeutic agents has become a crucial challenge for anti-tumor treatment. In this study, a novel redox-responsive polymeric prodrug (molecular weight, MW: 93.5 kDa) was produced by reversible addition–fragmentation chain transfer (RAFT) polymerization. The amphiphilic block polymer-doxorubicin (DOX) prodrug was employed to deliver a hydrophobic photosensitizer (PS), chlorin e6 (Ce6), and the as-prepared nanoscale system [NPs(Ce6)] was investigated as a chemo-photodynamic anti-cancer agent. The glutathione (GSH)-cleavable disulfide bond was inserted into the backbone of the polymer for biodegradation inside tumor cells, and DOX conjugated onto the polymer with a disulfide bond was successfully released intracellularly. NPs(Ce6) released DOX and Ce6 with their original molecular structures and degraded into segments with low MWs of 41.2 kDa in the presence of GSH. NPs(Ce6) showed a chemo-photodynamic therapeutic effect to kill 4T1 murine breast cancer cells, which was confirmed from a collapsed cell morphology, a lifted level in the intracellular reactive oxygen species, a reduced viability and induced apoptosis. Moreover, ex vivo fluorescence images indicated that NPs(Ce6) retained in the tumor, and exhibited a remarkable in vivo anticancer efficacy. The combinational therapy showed a significantly increased tumor growth inhibition (TGI, 58.53%). Therefore, the redox-responsive, amphiphilic block polymeric prodrug could have a great potential as a chemo-photodynamic anti-cancer agent.     

Bcl-2 family members as molecular targets in cancer therapy

Escape from apoptosis is often a hallmark of cancer cells, and is associated to chemotherapy resistance or tumor relapse. Proteins from the Bcl-2 family are the key regulators of the intrinsic pathway of apoptosis, controlling the point-of no-return and setting the threshold to engage the death machinery in response to a chemical damage. Therefore, Bcl-2 proteins have emerged as an attractive target to develop novel anticancer drugs. Current pharmacological approaches are focused on the use of peptides, small inhibitory molecules or antisense oligonucleotides to neutralize antiapoptotic Bcl-2 proteins, lowering the threshold and facilitating apoptosis of cancer cells. We discuss here recent advances in the development of Bcl-2 targeted anticancer therapies.     

光动力疗法联合支架置入治疗食管癌所致气道狭窄的效果观察

目的：比较单纯支架置入与光动力治疗联合支架置入治疗食管癌所致气道狭窄的效果。方法2009年10月~2014年10月,收集武安市第一人民医院胸外科食管癌引起中央气道狭窄患者25例,将其随机分为两组,12例(试验组)给予支架置入后行光动力治疗,13例(对照组)行单纯支架置入,比较两组患者的气促评分情况、平均稳定期、平均生存期及并发症发生率。结果两组的气促评分改善情况差异无统计学意义(P跃0.05);试验组患者的平均稳定期、平均生存期明显延长(P<0.05),支气管再狭窄发生率降低(P<0.05)。结论光动力治疗联合支架置入是治疗食管癌所致气道狭窄的一项有效姑息治疗方法,可延长平均稳定期和平均生存期,降低支气管再狭窄发生率。     

Design and development of dendrimer photosensitizer-incorporated polymeric micelles for enhanced photodynamic therapy

Photodynamic therapy (PDT), which involves systemic administration of photosensitizers (PSs) followed by local photoillumination, is a promising method for the treatment of solid tumors and other diseases. Recently, considerable efforts have been devoted to the development of nanocarriers for the PS delivery with the aim of avoiding non-specific phototoxicity to normal tissues such as the skin. Here, we discuss the biological significance of the use of nanocarrier-encapsulated PSs in PDT. Also, we report our recent achievements on the development of dendrimer photosensitizer-loaded micelles as nanocarriers for PS delivery. We found that our nanocarriers greatly enhanced the PDT efficacy in vitro and in vivo, and also significantly reduced the skin phototoxicity. These results indicate the importance of a development strategy for nanocarriers and their great potential for clinical use. In addition, this review discusses the development of nanocarriers for emerging PDT-related technologies such as photodynamic diagnosis (PDD) and photochemical internalization (PCI).