细胞功能的光动力调控

Photodynamic action with a large number of photosensitisers has important practical implications such as photodynamic cancer therapy. But the cellular and molecular mechanisms involved have been rather poorly understood. In this paper, photodynamic modulation of cell signal transduction and the resultant changes in cellular function are reviewed, with a particular emphasis on smooth muscle and the pancreas.     

Mitochondria-based photodynamic anti-cancer therapy

As photodynamic therapy (PDT) becomes established as a treatment for cancer, there is increasing interest in identifying critical mechanisms of cell killing and understanding the bases for effective photosensitizers. The existence of multiple cellular targets makes it difficult to distinguish the critical events leading to cell death from PDT. However, with more sensitive techniques to detect photosensitizer localization, the isolation of PDT-resistant and -sensitive mutants and the use of innovative molecular and biochemical strategies to map cellular events occurring during and after photosensitization, some order is emerging from the chaos. The subcellular localization of many photosensitizers and the early responses to light activation indicate that mitochondria play a major role in photodynamic cell death. PDT with many agents which damage or inhibit different or multiple mitochondrial targets has many of the desirable characteristics for an effective anti-cancer therapy.     

The chlorophyll catabolite pheophorbide a as a photosensitizer for the photodynamic therapy

Pheophorbide a is a clorophyll catabolite that recently has drawn the attention of several investigators for its potential in photodynamic therapy. In this review we summarize its photophysical properties, phototoxicity, cellular localization, biodistribution and PDT activity as a free or conjugated molecule.     

Targeted photodynamic therapy via receptor mediated delivery systems

Targeted photodynamic therapy (PDT) offers the opportunity of enhancing photodynamic efficiency by directly targeting diseased cells and tissues. While antibody-conjugates have received the most attention, cellular transformations offer numerous other potent targets to exploit during the delivery of photosensitizers (PSs) for PDT. Alterations in receptor expression, increased levels of specific cell surface membrane lipids and proteins as well as changes in the cellular microenvironment all occur in diseased cells. Along with other biochemical and physiological changes that occur during diseased and malignant cell transformation, these factors have been utilized in order to improve the efficacy of PDT. Attempts have been made to either increase the uptake of the dye by the target cells and tissues or to improve subcellular localization so as to deliver the dye to photosensitive sites within the cells. This review discusses various PS bioconjugates that utilize these factors and summarizes the results obtained to date.     

共载多西他赛和IR820的化疗/光热/光动纳米粒的抗肿瘤增殖及转移作用考察

本课题采用改进的乳化溶剂蒸发法制备聚乳酸-羟基乙酸共聚物(PLGA)-聚乙烯亚胺(PEI)纳米粒,并通过亲疏水作用力和电性吸附原理分别将多西他赛(1)和光敏剂IR820共同装载于PLGA内核和PEI阳离子亲水外壳中。为使纳米粒具有长循环功能,选用负电性肝素(heparin,H)修饰在纳米粒表面使电荷翻转,得到共载药纳米粒(1@IR820/H NPs),从而实现将化疗/光热/光动3种肿瘤治疗相结合,达到理想的抗乳腺癌细胞增殖和转移的治疗效果。制备并表征了所得纳米粒的物理化学性质,并考察了其在体外经近红外光(808 nm)照射处理后对乳腺癌细胞4T1增殖和转移的影响。结果显示,所得的1@IR820/H NPs的粒径为(192.7±4.1)nm,ζ电位为(-22.6±1.9)mV。细胞摄取试验表明,与1@IR820/HNPs共孵育的4T1细胞经近红外光照射处理后,明显增强了摄取能力。体外活性氧试验表明,细胞摄取的增强可提高光动治疗效果。另外,共载药纳米粒的细胞毒性明显高于游离药物。抗肿瘤转移试验表明IR820及共载药纳米粒可抑制肿瘤细胞转移,并且Western Blot技术表征显示抗转移作用...     

Diacyllipid micelle-based nanocarrier for magnetically guided delivery of drugs in photodynamic therapy

We report the design, synthesis using nanochemistry, and characterization of a novel multifunctional polymeric micelle-based nanocarrier system, which demonstrates combined function of magnetophoretically guided drug delivery together with light-activated photodynamic therapy. Specifically, the nanocarrier consists of polymeric micelles of diacylphospholipid-poly(ethylene glycol) (PE-PEG) coloaded with the photosensitizer drug 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH), and magnetic Fe3O4 nanoparticles. The nanocarrier shows excellent stability and activity over several weeks. The physicochemical characterizations have been carried out by transmission electron micrography and optical spectroscopy. An efficient cellular uptake has been confirmed with confocal laser scanning microscopy. The loading efficiency of HPPH is practically unaffected upon coloading with the magnetic nanoparticles, and its phototoxicity is retained. The magnetic response of the nanocarriers was demonstrated by their magnetically directed delivery to tumor cells in vitro. The magnetophoretic control on the cellular uptake provides enhanced imaging and phototoxicity. These multifunctional nanocarriers demonstrate the exciting prospect offered by nanochemistry for targeting photodynamic therapy.     

Sharp pH-sensitive amphiphilic polypeptide macrophotosensitizer for near infrared imaging-guided photodynamic therapy

Tumor environmental sensitive polypeptide integrated photosensitizer is a platform for imaging-guided photodynamic therapy (PDT). However, the photosensitizer leakage during blood circulation, poor accumulation in tumor tissue and inferior quantum yield of singlet oxygen are still challenges. Herein, NHS-active boron-dipyrromethene derivative with bromine substituted NHS-BODIPY-Br₂ was first synthesized, which possessed high singlet oxygen generation efficiency and near infrared (NIR) fluorescence, and then it was conjugated to a sharp pH (6.36) sensitive polypeptide to achieve a macrophotosensitizer for NIR imaging-guided PDT. In vitro study showed that the macrophotosensitizer nanoparticles exhibited good cellular uptake and ability to kill cancer cells. Once accumulating in the tumor tissues, the nanoparticles can be demicellized by tumor acidity to promote cellular uptake, which could enlarge fluorescence signal intensity and enhance in vivo PDT therapeutic effect upon NIR laser irradiation. It provides a strategy to design photosensitizer conjugated tumor acidity sensitive polypeptide for NIR imaging-guided photodynamic therapy.     

金丝桃素提取物对乳腺癌细胞MDA231的光动力杀伤效应研究

目的研究贯叶金丝桃中金丝桃素（HY）提取物对人乳腺癌细胞株MDA231的体外光动力杀伤效应。方法通过测定胞内荧光强度来确定细胞对金丝桃素的吸收，用显微镜观察、MTT法和DNA电泳分析法来研究金丝桃素对细胞的生长抑制作用。结果光活化的金丝桃素对MDA231细胞有显著的体外杀伤效应，其抑制细胞生长的能力与HY的浓度及光照能量密切相关。结论金丝桃素提取物在光照下能明显抑制乳腺癌细胞的生长，金丝桃素用于治疗乳腺癌具有广阔的开发应用前景。     

基于新型光敏剂的光动力治疗在胆管癌中的应用

目的：验证新型叶绿素类光敏剂———2-1-己氧乙基-2-去乙烯基卟吩e6三钠盐（ HCE6）,光动力疗法对于QBC939系胆管癌细胞的光动力治疗作用,并探讨其量效关系。方法 CCK-8检测652 nm不同激光光强度下不同浓度（0、0．3、0．5、1．0、15、2．0 mg· L－1）光敏剂HCE6光动力处理下细胞的增殖率,得出最适光动力剂量。建立QBC939系胆管癌细胞荷瘤裸鼠模型,光敏剂尾静脉注射0．5 mg· kg－1,24 h后接受激光治疗（激光剂量：120 J· cm－2,功率0．2 W,治疗20 min）,激光治疗后1、3、5、7、10 d观察实验组和对照组瘤体体积变化差异,并对比观察瘤体病理变化。结果在最适光照强度2．7 J· cm－2（功率0．9 W,PDT处理5 min）剂量,随着光敏剂浓度升高,细胞增殖率逐渐下降,最适完全抑制浓度为1．5 mg· L－1;超过这个浓度,细胞增值率变化无差异。荷瘤裸鼠模型实验中实验组和对照组有明显肿瘤体积差异（P＜0．05）,光动力治疗第10天,实验组与对照组体积差异明显（P＜0．05）,实验组瘤块体积（0．5±0．010）cm3,而对照组（2．25±0．015）cm3。接受PDT组与对照组比较肿瘤生长速度明显受限。结论体内外实验表明光敏剂HCE6对QBC939系人胆管癌细胞生长具有明显的抑制作用。     

Preparation and improvement of release behavior of chitosan microspheres containing insulin

Sophisticated delivery systems, such as nanoparticles, represent a growing area in biomedical research. Nanoparticles (Np) were prepared using a solvent emulsion evaporation method (SEEM) to load zinc(II) phthalocyanine (ZnPc). Np were obtained using poly (d,l latic-co-glycolic acid) (PLGA). ZnPc is a second generation of photoactive agents used in photodynamic therapy.

ZnPc loaded PLGA nanoparticles were prepared by SEEM, characterized and available in cellular culture. The process yield and encapsulation efficiency were 80 and 70%, respectively. The nanoparticles have a mean diameter of 285 nm, a narrow size distribution with polydispersive index of 0.12, smooth surface and spherical shape. ZnPc loaded nanoparticles maintains its photophysical behavior after encapsulation. Photosensitizer release from nanoparticles was sustained with a moderate and burst effect of 15% for 3 days. The photocytotoxicity of ZnPc loaded PLGA Np was evaluated on P388-D1 cells what were incubated with ZnPc loaded Np (5 μM) by 6 h and exposed to red light (675 nm) for 120 s, and light dose of 30 J/cm². After 24 h of incubation, the cellular viability was determined, obtaining 61% of cellular death. All the physical–chemical, photophysical and photobiological measurements performed allow us conclude that ZnPc loaded PLGA nanoparticles is a promising drug delivery system for photodynamic therapy.     

Accumulation and photodynamic activity of chlorin e6 in cisplatin-resistant human lung cancer cells

Cisplatin or cis-diamminedichloroplatinum (II) (CDDP) is one of the most potent anticancer drugs, but the emergence of acquired resistance to CDDP is a major problem in clinical settings. The purpose of this study was to investigate and compare the cellular accumulation and photodynamic activity of chlorin e6, a photosensitizer, in human lung cancer A549 cell line and its CDDP-resistant subline. First, we established the CDDP-resistant (A549/CDDP) cell subline with fourfold greater half-maximal inhibitory concentration value of CDDP on cell growth than that of the parent A549 cells. The cellular accumulation of chlorin e6 was temperature sensitive, and there were no significant differences in chlorin e6 accumulation between the two cell lines. The mRNA expression levels of ABCC1, ABCC2, and ABCG2 in A549/CDDP cells were comparable to those in A549 cells, whereas ABCB1 mRNA level was significantly higher in A549/CDDP cells than in A549 cells. In consistent with chlorin e6 accumulation, chlorin e6-mediated photodynamic activity on A549/CDDP cells was similar to that on A549 cells, whereas no cytotoxicity was observed when these cell lines were kept in dark. Our observations suggest that CDDP resistance has no significant influence on accumulation and photodynamic activity of chlorin e6 in A549 cells.     

Peripheral and axial substitution of phthalocyanines with solketal groups: synthesis and in vitro evaluation for photodynamic therapy

Phthalocyanines (Pcs) are a class of photosensitizers (PSs) with a strong tendency to aggregate in aqueous environment, which has a negative influence on their photosensitizing ability in photodynamic therapy. Pcs with either peripheral or axial solketal substituents, that is, ZnPc(sol)8 and Si(sol)2Pc, respectively, were synthesized and their tendency to aggregate as well as their photodynamic properties in 14C and B16F10 cell lines were evaluated. The results were compared to more hydrophilic silicon Pcs, that is, Si(PEG750)2Pc and Pc4. The order of cellular uptake was Pc4 > ZnPc(sol)8 > Si(PEG750)2Pc > Si(sol2)Pc. In contrast, Si(sol2)Pc showed the highest photocytotoxicity, while ZnPc(sol)8 did not show any photocytotoxicity up to a concentration of 10 microM in both cell types. UV/vis spectroscopy showed that Si(sol)2Pc is less prone to aggregation than ZnPc(sol)8, which can explain the lack of photoactivity of the latter. Si(sol)2Pc was predominantly located in lipid droplets, whereas Si(PEG750)2Pc was homogeneously distributed in the cytosol, which is probably the main cause of their difference in photoactivity. The very high photodynamic efficacy of Si(sol)2Pc makes this PS an interesting candidate for future studies.     

Gallium phthalocyanine photosensitizers: carboxylation enhances the cellular uptake and improves the photodynamic therapy of cancers

The octacarboxyl gallium (GaPcC) and metal-free (H2PcC) phthalocyanines were prepared using the carboxyl as the peripheral substituent. The carboxylation improves the intracellular delivery of these two PcCs into KB and QGY cancer cells as compared to that of sulfonated aluminum phthalocyanines (AlPcS), a popularly used photosensitizer (PS). Moreover, GaPcC maintains high photoproduction of singlet oxygen. With a short incubation time of 3 hours, GaPcC accumulates sufficiently in both KB and QGY cells and improves photodynamic therapy (PDT) by effectively killing these cancer cells. AlPcS and H2PcC show much lower PDT effects under the same conditions, because AlPcS have a slow cellular uptake rate resulting in a low cellular amount and the ability of H2PcC to produce 1O2 is low. Carboxylation is a promising way to prepare water-soluble metal phthalocyanines (MPcCs) and facilitates the cellular uptake of MPcCs for PDT improvement.     

Apoptosis following photodynamic tumor therapy: induction, mechanisms and detection

As a treatment modality for malign and certain non-malignant diseases, photodynamic therapy (PDT) involves a two step protocol which consists of the (selective) uptake and accumulation of a photosensitizing agent in target cells and the subsequent irradiation with light in the visible range. Reactive oxygen species (ROS) produced during this process cause cellular damage and, depending on the treatment dose/severity of damage, lead to either cellular repair/survival, apoptotic cell death or necrosis. PDT-induced apoptosis has been focused on during the last years due to the intimate connection between ROS generation, mitochondria and apoptosis; by this PDT employs mechanisms different to those in the action of radio- and chemotherapeutics, giving rise to the chance of apoptosis induction by PDT even in cells resistant to conventional treatments. In this review, the (experimental) variables determining the cellular response after PDT and the known mechanistic details of PDT-triggered induction and execution of apoptosis are discussed. This is accompanied by a critical evaluation of wide-spread methods employed in apoptosis detection with special respect to in vitro/cell-based methodology.     

Photosensitizer-assembled PEGylated graphene-copper sulfide nanohybrids as a synergistic near-infrared phototherapeutic agent

Objectives: Stimulative nanostructures play a crucial role in developing the smart nanomedicine for high therapeutic efficacy with minimum adverse effects. Herein, a near-infrared (NIR) light-responsive nanohybrids p-nanographene oxide (GO)-copper sulfide (CuS)/indocyanine green (ICG) comprised of GO, CuS nanoparticles and photosensitizer ICG was fabricated to couple the photothermal property of CuS and photodynamic effect of ICG in one system in order to achieve the synergistic phototherapy.

Methods: pGO-CuS/ICG was constructed by self-assembling ICG on pGO-CuS nanostructure. Its physicochemical, photothermal and photodynamic properties were studied by spectroscopic methods. The in vitro cellular uptake, cytotoxicity, the single/combined photothermal therapeutic (PTT) and photodynamic therapeutic (PDT) effects were investigated with biological techniques.

Results: pGO-CuS/ICG exhibited high efficacy of photothermal conversation and singlet oxygen generation under NIR laser excitation. It entered into the target cancer cells probably via passive transmembrane pathway and exerted obvious PTT and PDT effect against the tumor cells upon irradiation with the respective 940 and 808 nm lasers. In particular, the tremendous synergistic efficacy of PDT and PTT had been demonstrated by tuning the NIR laser combined irradiation.

Conclusions: This study promises the future applications of pGO-CuS/ICG as a NIR light activable theranostic nanodrug for deep-seated cancer noninvasive phototherapy.     

藻蓝蛋白亚基脂质体制备及其光动力学抗肿瘤作用实验

本研究建立了藻蓝蛋白亚基脂质体的制备方法，检测其对肿瘤细胞转染及光动力杀伤作用(PDT)效果。采用薄膜水合-超声分散法制备藻蓝蛋白亚基脂质体，测定其粒径大小及分布，荧光显微镜观察藻蓝蛋白亚基(PCS)及其脂质体(PCS-lip)的细胞转染率，MTT法检测藻蓝蛋白亚基及其脂质体对肿瘤细胞光动力杀伤效果。结果显示脂质体的粒径为80～160 nm，包封率为42.3%；在质量浓度为100 μg·mL^-1时，藻蓝蛋白亚基脂质体对小鼠肉瘤细胞S180转染率在2 h达到(18.5±0.8)%，4 h为(23.1±0.9)%，5～6 h转染率不再上升。肿瘤细胞光动力杀伤实验表明，在0～200 μg·mL^-1内，光照剂量为22 J·cm^-2时，随着藻蓝蛋白亚基及其脂质体浓度的增加，对胃癌细胞BGC-823和S180的光敏作用也随之增强；在200 μg·mL^-1时PCS-lip对两种细胞生存率分别降低为(45±5.2)%和(36±5.5)%，PCS-lip-PDT组与PCS-PDT组对细胞生存率影响有显著性差异(P<0.05)。研究结果表明，藻蓝蛋白亚基脂质体可很好地保持藻蓝蛋白亚基的生物活性，在相同蛋白浓度时藻蓝蛋白亚基脂质体比藻蓝蛋白亚基更快地转染进肿瘤细胞，药物作用的最佳时间为4 h。在相同浓度及光照剂量的情况下，藻蓝蛋白亚基脂质体对肿瘤细胞的光动力学作用略强于藻蓝蛋白亚基。     

非手术综合治疗巨大型尖锐湿疣13例疗效观察

目的 观察钬激光联合光动力及冷冻综合治疗巨大型尖锐湿疣的疗效和安全性.方法 13例肛周、外生殖器巨大型尖锐湿疣患者,男8例、女5例,通过钬激光消融疣体,清理创面干净后,立即给予氨基酮戊酸光动力治疗,复发后给予光动力或冷冻治疗,共治疗1～8次.结果 13例巨大疣体均经钬激光消融1次清除,随后进行的光动力治疗中,1次治疗即痊愈者4例;余9例经过2～3次的光动力结合冷冻治疗中获得痊愈;随访3～6月未复发.不良反应主要是术中疼痛不适和术后瘢痕及色素改变.结论 钬激光联合光动力及冷冻非手术综合治疗对巨大型尖锐湿疣安全、有效.     

Multifunctionalized mesoporous silica nanoparticles for the in vitro treatment of retinoblastoma: Drug delivery, one and two-photon photodynamic therapy

In this work, we focused on mesoporous silica nanoparticles (MSN) for one photon excitated photodynamic therapy (OPE-PDT) combined with drug delivery and carbohydrate targeting applied on retinoblastoma, a rare disease of childhood. We demonstrate that bitherapy (camptothecin delivery and photodynamic therapy) performed with MSN on retinoblastoma cancer cells was efficient in inducing cancer cell death. Alternatively MSN designed for two-photon excited photodynamic therapy (TPE-PDT) were also studied and irradiation at low fluence efficiently killed retinoblastoma cancer cells.     

新一代光动力治疗联合化疗治疗肺癌并大量胸腔积液疗效观察及护理

目的观察新一代光动力治疗联合化疗治疗肺癌伴大量胸腔积液的疗效及护理作用探讨。方法选择经组织学和（或）细胞学确诊的肺癌伴胸腔积液患者71例作为观察组,另选同期经CT或B型超声或胸部X线片确诊的肺癌伴胸腔积液患者63例作为对照组。观察组采用新一代光动力治疗联合常规化疗进行治疗,对照组单用化疗治疗。比较2组临床疗效及不良反应发生情况。结果观察组总有效率为85.9%高于对照组的55.6%,差异有统计学意义（P〈0.05）;2组均未出现明显不良反应。结论新一代光动力治疗联合常规化疗治疗肺癌伴大量胸腔积液安全、有效、毒副作用小;良好的护理对保证光动力治疗恶性肿瘤的顺利进行起着非常重要的作用。     

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。