阿糖胞苷金属卟啉衍生物的合成及光动力抗肿瘤活性

设计并合成了阿糖胞苷卟啉衍生物(AHP), 并通过金属插入反应获得了4种金属卟啉衍生物, 采用核磁共振、红外光谱、紫外-可见光谱和质谱等手段对化合物的结构进行了表征.光动力抗肿瘤活性实验结果表明, 含药浓度为25 μmol/L的ZnAHP经光照30 min后对人乳腺癌MCF-7细胞的光动力杀伤率平均达(45.86±8.20)%.     

Chlorin photosensitizers sterically designed to prevent self-aggregation

The synthesis and photophysical evaluation of new chlorin derivatives are described. The Diels-Alder reaction between protoporphyrin IX dimethyl ester and substituted maleimides furnishes endo-adducts that completely prevent the self-aggregation of the chlorins. Fluorescence, resonant light scattering (RLS) and (1)H NMR experiments, as well as X-ray crystallographic have demonstrated that the configurational arrangement of the synthesized chlorins prevent π-stacking interactions between macrocycles, thus indicating that it is a nonaggregating photosensitizer with high singlet oxygen (Φ(Δ)) and fluorescence (Φ(f)) quantum yields. Our results show that this type of synthetic strategy may provide the lead to a new generation of PDT photosensitizers.     

PHOTODYNAMIC EFFECTS OF NEW SILICON PHTHALOCYANINES: In vitro STUDIES UTILIZING RAT HEPATIC MICROSOMES AND HUMAN ERYTHROCYTE GHOSTS AS MODEL MEMBRANE SOURCES

Abstract— Photodynamic therapy (PDT) of cancer is a modality that relies upon the irradiation of tumors with visible light following selective uptake of a photosensitizer by the tumor tissue. There is considerable emphasis to define new photosensitizers suitable for PDT of cancer. In this study we evaluated six phthalocyanines (Pc) for their photodynamic effects utilizing rat hepatic microsomes and human erythrocyte ghosts as model membrane sources. Of the newly synthesized Pc, two showed significant destruction of cytochrome P-450 and monooxygenase activities, and enhancement of lipid peroxidation, when added to microsomal suspension followed by irradiation with ∼ 675 nm light. These two Pc named SiPc IV (HOSiPcOSi[CH₃]₂[CH₂]₃N[CH₃]₂) and SiPc V (HOSiPcOSi[CH₃]₂[CH₂]₃N[CH₃]₃¹ I) showed dose-dependent photodestruction of cytochrome P-450 and monooxygenase activities in liver microsomes, and photoenhancement of lipid peroxidation, lipid hydroperoxide formation and lipid fluorescence in rnicrosomes and erythrocyte ghosts. Compared to chloroaluminum phthalocyanine tetrasulfonate, SiPc IV and SiPc V produced far more pronounced photodynamic effects. Sodium azide, histidine, and 2,5-dimethylfuran, the quenchers of singlet oxygen, afforded highly significant protection against SiPc IV- and SiPc V-mediated photodynamic effects. However, to a lesser extent, the quenchers of superoxide anion, hydrogen peroxide and hydroxyl radical also showed some protective effects. These results suggest that SiPc IV and SiPc V may be promising photosensitizers for the PDT of cancer.     

Synthesis of beta-galactose-conjugated chlorins derived by enyne metathesis as galectin-specific photosensitizers for photodynamic therapy.

A first report on the synthesis and biological evaluation of the beta-galactose-conjugated purpurinimides (a class of chlorins containing a six-membered fused imide ring system) as Gal-1 (galectin-1) recognized photosensitizers, prepared from purpurin-N-propargylimide via enyne metathesis, is discussed. On the basis of examination of the available crystal structure of the galectin-1 N-acetyllactose amine complex, it was considered that the chlorin-based photosensitizers could be introduced into a carbohydrate skeleton to expand the repertoire of the galectin-1-specific ligands. Preliminary molecular modeling analysis utilizing the modeled photosensitizers and the available crystal structures of galectin-carbohydrate complexes indicated that addition of the photosensitizer to the carbohydrate moiety at an appropriate position does not interfere with the galectin-carbohydrate recognition. Under similar drug and light doses, compared to the free purpurinimide analogue, the purpurinimides conjugated either with galactose or with lactose (Gal(beta1-4)-Glc) produced a considerable increase in photosensitizing efficacy in vitro. This indicates the possibility for development of a new class of specific photosensitizers for photodynamic therapy (PDT) based on recognition of a cellular receptor.     

酞菁配合物的结构与其光动力抗癌活性

光动力治疗是一种正在发展中的治疗癌症的新方法.主要是利用抗癌光敏剂可优先在 肿瘤组织中富集的特性和随后在适当波长的光照下所引发的光敏化反应来杀死癌肿瘤.自198 5年以来,酞菁配合物作为抗癌光敏剂的研究越来越引人注目. 此文在总结51篇参考文献的 基础上,提出了酞菁配合物的结构与其光动力抗癌活性的某些相关性,着重讨论了中心离子 、环取代基、轴向配体对光动力活性和相关物化性质的影响.得出的一个主要的结论是两亲 性酞菁是极具潜力的光敏剂.     

肿瘤光动力治疗临床应用的光敏剂及其研究概况

光动力治疗是一种非侵蚀性并具有一定靶向性的肿瘤治疗新方法。 光动力治疗需要光敏剂、光和氧结合产生光动力反应。 光敏剂是光动力治疗的关键和物质基础。 本文概括介绍了已上市的和已被批准进入临床试验中的光敏剂,并根据其分子的骨架结构,将其分为分卟啉类、二氢卟吩（叶绿素）类和菌绿素/酞菁三类。 同时从理想光敏剂应具备特点出发,探讨了研究中的光敏剂和光动力治疗的发展前景。     

Metal Nanoparticles for Photodynamic Therapy: A Potential Treatment for Breast Cancer

Breast cancer (BC) is the most common malignant tumor in women worldwide, which seriously threatens women’s physical and mental health. In recent years, photodynamic therapy (PDT) has shown significant advantages in cancer treatment. PDT involves activating photosensitizers with appropriate wavelengths of light, producing transient levels of reactive oxygen species (ROS). Compared with free photosensitizers, the use of nanoparticles in PDT shows great advantages in terms of solubility, early degradation, and biodistribution, as well as more effective intercellular penetration and targeted cancer cell uptake. Under the current circumstances, researchers have made promising efforts to develop nanocarrier photosensitizers. Reasonably designed photosensitizer (PS) nanoparticles can be achieved through non-covalent (self-aggregation, interfacial deposition, interfacial polymerization or core-shell embedding and physical adsorption) or covalent (chemical immobilization or coupling) processes and accumulate in certain tumors through passive and/or active targeting. These PS loading methods provide chemical and physical stability to the PS payload. Among nanoparticles, metal nanoparticles have the advantages of high stability, adjustable size, optical properties, and easy surface functionalization, making them more biocompatible in biological applications. In this review, we summarize the current development and application status of photodynamic therapy for breast cancer, especially the latest developments in the application of metal nanocarriers in breast cancer PDT, and highlight some of the recent synergistic therapies, hopefully providing an accessible overview of the current knowledge that may act as a basis for new ideas or systematic evaluations of already promising results.     

Intracellular localization is a cofactor for the phototoxicity of protoporphyrin IX in the gastrointestinal tract: in vitro study

Photodynamic therapy (PDT) is a new treatment modality for solid tumors as well as for flat lesions of the gastrointestinal tract. Although the use of 5-aminolevulinic acid-induced protoporphyrin IX (PPIX) shows important advantages over other photosensitizers, the main mechanisms of phototoxicity induced are still poorly understood. Three human colon carcinoma cell lines with variable degrees of differentiation and a normal colon fibroblast cell line were used to generate a suitable in vitro model for investigation of photosensitizer concentration as well as the applied light dose. Also, the effects of intracellular photosensitizer localization on efficiency of PDT were examined, and cellular parameters after PDT (morphology, mitochondrial transmembrane potential, membrane integrity and DNA fragmentation) were analyzed to distinguish between PDT-induced apoptosis from necrosis. The fibroblast cell line was less affected by phototoxicity than the tumor cells to a variable degree. Well-differentiated tumor cells showed higher toxicity than less-differentiated cells. After irradiation, cell lines with cytosolic or mitochondrial PPIX localization indicate a loss of mitochondrial transmembrane potential resulting in growth arrest, whereas membrane-bound PPIX induces a loss of membrane integrity and consequent necrosis. Although the absolute amount of intracellular photosensitizer concentration plays the main determining role for PDT efficiency, data indicate that intracellular localization has additional effects on the mode of cell damage.     

Supramolecular nanoparticles constructed by orthogonal assembly of pillar[5]arene-cyclodextrin dimacrocycle for chemo-photodynamic combination therapy

Chemotherapy combined with photodynamic therapy has emerged as a promising strategy for cancer treatment. However, simultaneously delivering chemotherapeutic drugs and photosensitizers and precisely adjusting the ratio of the two components as needed remains a challengeable task. Herein, novel supramolecular nanoparticles (donated as BODIPY-CPT-NPs) for chemo-photodynamic combination cancer therapy are constructed from a glutathione-responsive camptothecin-based prodrug, BODIPY photosensitizer, and dimacrocyclic host molecule through orthogonal host-guest recognitions and co-assembly. With this strategy, the ratio of prodrugs and photosensitizers in nanoparticles can be easily and precisely controlled as needed. Benefiting from the strong host-guest interactions and stable self-assembly, the nanoparticles exhibit excellent stability and photobleaching resistance. Furthermore, camptothecin can be released from nanoparticles for chemotherapy in the presence of reduction agent and single oxygen can be efficiently generated for PDT with light irradiation. The combined effects of the BODIPY-CPT-NPs have been verified in CT26 and HeLa cancer cells.     

A Multiresponsive Nanohybrid to Enhance the Lysosomal Delivery of Oxygen and Photosensitizers

Photodynamic therapy (PDT) is a promising cancer ablation method, but its efficiency is easily affected by several factors, such as the insufficient delivery of photosensitizers, low oxygen levels as well as long distance between singlet oxygen and intended organelles. A multifunctional nanohybrid, named MGAB, consisting of gelatin-coated manganese dioxide and albumin-coated gold nanoclusters, was designed to overcome these issues by improving chlorin e6 (Ce6) delivery and stimulating oxygen production in lysosomes. MGAB were quickly degraded in a high hydrogen peroxide, high protease activity, and low pH microenvironment, which is closely associated with tumor growth. The Ce6-loaded MGAB were picked up by tumor cells through endocytosis, degraded within the lysosomes, and released oxygen and photosensitizers. Upon near-infrared light irradiation, the close proximity of oxygen with photosensitizer within lysosomes enabled the production of cytotoxic singlet oxygen, resulting in more effective PDT.     

Quantitative in vitro demonstration of two-photon photodynamic therapy using photofrin and visudyne

Photodynamic therapy (PDT), the combined action of a photosensitizer and light to produce a cytotoxic effect, is an approved therapy for a number of diseases. At present, clinical PDT treatments involve one-photon excitation of the photosensitizer. A major limitation is that damage may be caused to healthy tissues that have absorbed the drug and lie in the beam path. Two-photon excitation may minimize this collateral damage, as the probability of absorption increases with the square of the light intensity, enabling spatial confinement of the photosensitizer activation. A potential application is the treatment of the wet-form of age-related macular degeneration, the foremost cause of central vision loss in the elderly. Herein, the commercial photosensitizers Visudyne and Photofrin are used to demonstrate quantitative in vitro two-photon PDT. A uniform layer of endothelial cells (YPEN-1) was irradiated with a Ti:sapphire laser (300 fs, 865 nm, 90 MHz) using a confocal scanning microscope. Quantification of the two-photon PDT effect was achieved using the permeability stain Hoechst 33258 and a SYTOX Orange viability stain. Visudyne was found to be around seven times more effective as a two-photon photosensitizer than Photofrin under the conditions used, consistent with its higher two-photon absorption cross-section. We also demonstrate for the first time the quadratic intensity dependence of cellular two-photon PDT. This simple in vitro method for quantifying the efficacy of photosensitizers for two-photon excited PDT will be valuable to test specifically designed two-photon photosensitizers before proceeding to in vivo studies in preclinical animal models.     

A Single-wavelength NIR-triggered Polymer for in situ Generation of Peroxynitrite(ONOO~–) to Enhance Phototherapeutic Efficacy

Phototherapies including photodynamic therapy(PDT) and photothermal therapy(PTT) are the most promising and non-invasive cancer treatments. However, the efficacy of mono-therapy of PDT or PTT is often limited by the phototherapeutic defects such as low light penetration depth of photosensitizers and insufficiency of photothermal agents. Peroxynitrite(ONOO~-) has been proved to be an efficient oxidizing and nitrating agent that involves in various physiological and pathological processes. Therefore, ONOO~-produced in tumor site could be an effective treatment in cancer therapy. Herein, a novel cyanine dye-based(Cy7) polymer nanoplatform is developed for enhanced phototherapy by in situ producing ONOO~-. The Cy7 units in the nanoparticles can not only be served as the photosensitizer to produce reactive oxygen species(ROS) including singlet oxygen and superoxide anion for PDT, but also be used as a heat source for PTT and the release of NO gas from N-nitrosated napthalimide(NORM) at the same time. Since NO can react quickly with superoxide anion to generate ONOO~-, the enhanced phototherapy could be achieved by in situ ONOO~-produced by PCy7-NO upon exposure to the near infrared(NIR) light. Therefore, the NIRtriggered Cy7-based nanoplatform for ONOO~--enhanced phototherapy may provide a new perspective in cancer therapy.     

姜黄素桥连卟啉光敏剂的合成及表征

为了开发新的高效光动力治疗光敏剂, 以2-(2-羟基萘基)-5,10,15,20-四苯基卟啉及其Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ)配合物为原料, 利用1,6-二溴己烷桥连具有抗癌活性的小分子姜黄素, 设计合成4个新型的天然产物桥连卟啉化合物. 通过UV, ¹H NMR, IR, MS及元素分析等手段对该新型光敏药剂进行了结构表征; 在此基础上, 采用凝胶电泳法考察了化合物在光照和无光照条件下对pBR322质粒DNA的切割能力. 作为潜在光敏剂与DNA相互作用的初步研究表明, 其与DNA结合能力较强, 具有明显的光敏切割效果.     

Photodynamic Therapy with Tumor Cell Discrimination through RNA-Targeting Ability of Photosensitizer

Photodynamic therapy (PDT) represents an effective treatment to cure cancer. The targeting ability of the photosensitizer is of utmost importance. Photosensitizers that discriminate cancer cells can avoid the killing of normal cells and improve PDT efficacy. However, the design and synthesis of photosensitizers conjugated with a recognition unit of cancer cell markers is complex and may not effectively target cancer. Considering that the total RNA content in cancer cells is commonly higher than in normal cells, this study has developed the photosensitizer QICY with RNA-targeting abilities for the discrimination of cancer cells. QICY was specifically located in cancer cells rather than normal cells due to their stronger electrostatic interactions with RNA, thereby further improving the PDT effects on the cancer cells. After intravenous injection into mice bearing a xenograft tumor, QICY accumulated into the tumor location through the enhanced permeability and retention effect, automatically targeted cancer cells under the control of RNA, and inhibited tumor growth under 630 nm laser irradiation without obvious side effects. This intelligent photosensitizer with RNA-targeting ability not only simplifies the design and synthesis of cancer-cell-targeting photosensitizers but also paves the way for the further development of highly efficient PDTs.     

Porphyrin and Nonporphyrin Photosensitizers in Oncology: Preclinical and Clinical Advances in Photodynamic Therapy

Photodynamic therapy (PDT) is now a well-recognized modality for the treatment of cancer. While PDT has developed progressively over the last century, great advances have been observed in the field in recent years. The concept of dual selectivity of PDT agents is now widely accepted due to the relative specificity and selectivity of PDT along with the absence of harmful side effects often encountered with chemotherapy or radiotherapy. Traditionally, porphyrin-based photosensitizers have dominated the PDT field but these first generation photosensitizers have several disadvantages, with poor light absorption and cutaneous photosensitivity being the predominant side effects. As a result, the requirement for new photosensitizers, including second generation porphyrins and porphyrin derivatives as well as third generation photosensitizers has arisen, with the aim of alleviating the problems encountered with first generation porphyrins and improving the efficacy of PDT. The investigation of nonporphyrin photosensitizers for the development of novel PDT agents has been considerably less extensive than porphyrin-based compounds; however, structural modification of nonporphyrin photosensitizers has allowed for manipulation of the photochemotherapeutic properties. The aim of this review is to provide an insight into PDT photosensitizers clinically approved for application in oncology, as well as those which show significant potential in ongoing preclinical studies.     

Photodynamic Therapy Efficacy Enhanced by Dynamics: The Role of Charge Transfer and Photostability in the Selection of Photosensitizers

Progress in the photodynamic therapy (PDT) of cancer should benefit from a rationale to predict the most efficient of a series of photosensitizers that strongly absorb light in the phototherapeutic window (650–800 nm) and efficiently generate reactive oxygen species (ROS=singlet oxygen and oxygen‐centered radicals). We show that the ratios between the triplet photosensitizer–O₂ interaction rate constant (k_D) and the photosensitizer decomposition rate constant (k_d), k_D/k_d, determine the relative photodynamic activities of photosensitizers against various cancer cells. The same efficacy trend is observed in vivo with DBA/2 mice bearing S91 melanoma tumors. The PDT efficacy intimately depends on the dynamics of photosensitizer–oxygen interactions: charge transfer to molecular oxygen with generation of both singlet oxygen and superoxide ion (high k_D) must be tempered by photostability (low k_d). These properties depend on the oxidation potential of the photosensitizer and are suitably combined in a new fluorinated sulfonamide bacteriochlorin, motivated by the rationale.     

Highly efficient and photostable photosensitizer based on BODIPY chromophore

Photosensitizers are reagents that produce reactive oxygen species upon light illumination and are commonly used to study oxidative stress or for photodynamic therapy. There are many available photosensitizers, but most have limitations, such as low photostability, structural instability, or a limited usable range of solvent conditions. Here, we describe a novel photosensitizer scaffold (2I-BDP) based on the unique characteristics of the BODIPY chromophore (i.e., high extinction coefficient, high photostability, and insensitivity to solvent environment). 2I-BDP shows stronger near-infrared singlet oxygen luminescence emission and higher photostability than the well-known photosensitizer, Rose Bengal. Unlike other photosensitizers, this scaffold is widely applicable under various conditions, including lipophilic and aqueous environments. HeLa cells loaded with 2I-BDP could be photosensitized by light illumination, demonstrating that 2I-BDP is potentially useful as a reagent for cell photosensitization, oxidative stress studies, or PDT.     

Perfluorocarbon nanomaterials for photodynamic therapy

Photodynamic therapy (PDT) is a treatment modality in which a photosensitizer is irradiated with light, producing reactive oxygen species, often via energy transfer with oxygen. As it is common for tumors to be hypoxic, methods to deliver photosensitizer and oxygen are desirable. One such approach is the use of perfluorocarbons, molecules in which all C–H bonds are replaced with C–F bonds, to co-deliver oxygen because of the high solubility of gases in perfluorocarbons. This review highlights the benefits and limitations of several fluorinated nanomaterial architectures for use in PDT.     

Highly Efficient,Conjugated‐Polymer‐Based Nano‐Photosensitizers for Selectively Targeted Two‐Photon Photodynamic Therapy and Imaging of Cancer Cells

Two‐photon photodynamic therapy (2P‐PDT) is a promising noninvasive treatment of cancers and other diseases with three‐dimensional selectivity and deep penetration. However, clinical applications of 2P‐PDT are limited by small two‐photon absorption (TPA) cross sections of traditional photosensitizers. The development of folate receptor targeted nano‐photosensitizers based on conjugated polymers is described. In these nano‐photosensitizers, poly{9,9‐bis[6′′‐(bromohexyl)fluorene‐2,7‐ylenevinylene]‐co‐alt‐1,4‐(2,5‐dicyanophenylene)}, which is a conjugated polymer with a large TPA cross section, acts as a two‐photon light‐harvesting material to significantly enhance the two‐photon properties of the doped photosensitizer tetraphenylporphyrin (TPP) through energy transfer. These nanoparticles displayed up to 1020‐fold enhancement in two‐photon excitation emission and about 870‐fold enhancement in the two‐photon‐induced singlet oxygen generation capability of TPP. Surface‐functionalized folic acid groups make these nanoparticles highly selective in targeting and killing KB cancer cells over NIH/3T3 normal cells. The 2P‐PDT activity of these nanoparticles was significantly improved, potentially up to about 1000 times, as implied by the enhancement factors of two‐photon excitation emission and singlet oxygen generation. These nanoparticles could act as novel two‐photon nano‐photosensitizers with combined advantages of low dark cytotoxicity, targeted 2P‐PDT with high selectivity, and simultaneous two‐photon fluorescence imaging capability; these are all required for ideal two‐photon photosensitizers.     

Enhanced Photodynamic Therapy by Reduced Levels of Intracellular Glutathione Obtained By Employing a Nano‐MOF with CuII as the Active Center

In photodynamic therapy (PDT), the level of reactive oxygen species (ROS) produced in the cell directly determines the therapeutic effect. Improvement in ROS concentration can be realized by reducing the glutathione (GSH) level or increasing the amount of photosensitizer. However, excessive amounts photosensitizer may cause side effects. Therefore, the development of photosensitizers that reduce GSH levels through synergistically improving ROS concentration in order to strengthen the efficacy of PDT for tumor is important. We report a nano‐metal–organic framework (Cu^II‐metalated nano‐MOF {CuL‐[AlOH]₂}_n (MOF‐2, H₆L=mesotetrakis(4‐carboxylphenyl)porphyrin)) based on Cu^II as the active center for PDT. This MOF‐2 is readily taken up by breast cancer cells, and high levels of ROS are generated under light irradiation. Meanwhile, intracellular GSH is considerably decreased owing to absorption on MOF‐2; this synergistically increases ROS concentration and accelerates apoptosis, thereby enhancing the effect of PDT. Notably, based on the direct adsorption of GSH, MOF‐2 showed a comparable effect with the commercial antitumor drug camptothecin in a mouse breast cancer model. This work provides strong evidence for MOF‐2 as a promising new PDT candidate and anticancer drug.