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Photodynamic therapy of cancer with liposomal photosensitizers
摘要： The photodynamic reaction involves the light-induced generation of an excited state in a photosensitizer molecule (PS), which then results in the formation of reactive oxygen species in the presence of oxygen, or a direct modification of a cellular molecule. Most PSs are porphyrinoids, which are highly lipophilic, and are administered usually in liposomes to facilitate their effective delivery to target cells. The currently available liposomal formulations are Visudyne R(cid:2) and Fospeg R(cid:2). Novel PSs were developed and tested for their photodynamic activity against cancer cells. Several compounds were highly phototoxic to oral cancer cells both in free and liposome-encapsulated form, with nanomolar IC50 values. The lowest IC50s (7–13 nM) were obtained with a PS encapsulated in cationic liposomes.
关键词： photosensitizer,liposome,photodynamic therapy,cytotoxicity,porphyrazine
更新于2025-09-23 15:21:21
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Interaction of a phenazinium-based photosensitizer with surface active ionic liquid micelles: Investigating the effect of cyclodextrins on SAIL micelles
摘要： The present study depicts a spectroscopic investigation on the binding interaction of a phenazinium-based photosensitizer, phenosafranin (PSF) with a micelle forming surface active ionic liquid (SAIL), 1-butyl-3-methylimidazolium octyl sulfate (Bmim Os). The steady-state as well as time-resolved spectroscopic results reveal the binding of PSF with the micelles of the ionic liquid. The modulations of the spectral properties of PSF on interacting with Bmim Os micelles have been further employed to monitor the effect of various cyclodextrins, αCD, βCD and γCD (with varying dimensions of the hydrophobic cavity), on the Bmim Os micellar aggregates. The effective disruption of the Bmim Os micelles in presence of CDs is confirmed from the reduced size of Bmim Os micelles with added CD as observed from the DLS results.
关键词： Photosensitizer,Surface Active Ionic Liquid,Effect of Cyclodextrins,Binding Interaction,Bmim Os Micelles
更新于2025-09-23 15:21:01
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A genetically encoded photosensitizer protein facilitates the rational design of a miniature photocatalytic CO2-reducing enzyme
摘要： Photosensitizers, which harness light energy to upgrade weak reductants to strong reductants, are pivotal components of the natural and artificial photosynthesis machineries. However, it has proved difficult to enhance and expand their functions through genetic engineering. Here we report a genetically encoded, 27 kDa photosensitizer protein (PSP), which facilitates the rational design of miniature photocatalytic CO2-reducing enzymes. Visible light drives PSP efficiently into a long-lived triplet excited state (PSP*), which reacts rapidly with reduced nicotinamide adenine dinucleotide to generate a super-reducing radical (PSP?), which is strong enough to reduce many CO2-reducing catalysts. We determined the three-dimensional structure of PSP? at 1.8 ? resolution by X-ray crystallography. Genetic engineering enabled the site-specific attachment of a nickel–terpyridine complex and the modular optimization of the photochemical properties of PSP, the chromophore/catalytic centre distance and the catalytic centre microenvironment, which culminated in a miniature photocatalytic CO2-reducing enzyme that has a CO2/CO conversion quantum efficiency of 2.6%.
关键词： quantum efficiency,photosensitizer protein,visible light,photocatalytic CO2-reducing enzymes,X-ray crystallography,nickel–terpyridine complex,genetic engineering
更新于2025-09-23 15:21:01
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Photodynamic therapy in the treatment of oral leukoplakia: a systematic review
摘要： Objective: The aim of the present study was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral leukoplakia (OLK). Methods: This systematic review aimed to address the following focused question: “Is photodynamic therapy effective in the management of oral leukoplakia?’’ PubMed/Medline, EMBASE, ISI Web of Knowledge, OVID, CNKI, and WANFANG DATA were searched up to and including June 2018 using different combinations of the following keywords: photodynamic therapy, leukoplakia, oral dysplasia, oral precancers, and oral premalignant lesions. Results: Sixteen studies were included in the present study. A total of 352 patients was included in this review, with the age ranging from 20 to 79 years. Photosensitizers used were aminolevulinic acid, Photofrin, methylene blue, and chlorine-e6. Laser wavelength, duration of irradiation, and power density were 420 to 660 nm, 60 to 1000 seconds, and 100 to 150 mW/cm2, respectively. On the whole, the rates of complete response and partial response were 32.9% and 43.2%, and the sum was 76.1%. The follow-up period ranged from 1 month to 119 months. The recurrence rate of OLK was 0-60%. Conclusion: PDT seems to be a useful therapeutic strategy in the management of oral leukoplakia as a non-surgical treatment. Further RCTs with long follow-up period, standardized PDT parameters, and comparing efficacy of PDT with various therapies are expected to acquire definite conclusions.
关键词： Light source,Oral dysplasia,Oral leukoplakia,Photosensitizer,Photodynamic therapy,Oral premalignant lesions
更新于2025-09-23 15:21:01
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Clinical trial of photodynamic therapy for peripheral-type lung cancers using a new laser device in a pilot study
摘要： Introduction/Aim: Photodynamic therapy (PDT) involves the use of a tumor-specific photosensitizer and laser irradiation, and one of the treatment options recommended for early centrally located lung cancers, but not yet for peripheral-type lung cancers. We developed a new laser probe, the composite-type optical fiberscope (COF), which allows accurate laser irradiation of a cancer lesion with simultaneous visualization of the lesion. Methods: This phase I study was conducted in 7 patients with peripheral lung cancers (primary tumor ≤20 mm in diameter). We performed endobronchial PDT for these patients using the new laser probe and talaporfin sodium as the photosensitizer. Results: We performed PDT for 3 patients with peripheral lung cancer using a laser dose of 50 J/cm2 at 120 mW, and confirmed the feasibility of using this dose. Then, we escalated the laser dose to 100 J/cm2 in 4 additional patients. A total of 7 patients met our inclusion criteria. Evaluation at 2 weeks and 3 months after the PDT revealed no complication such as pneumonia or pneumothorax. At the evaluation conducted 6 months later, we found CR in 3 cases and SD in the remaining 4 cases. Conclusion: PDT was found to be a feasible and non-invasive treatment modality for early peripheral-type lung cancer. In the future, PDT could become a standard treatment option for peripheral-type lung cancer.
关键词： Photodynamic Therapy (PDT),laser,peripheral type lung cancer,clinical trial,photosensitizer,endobronchial treatment
更新于2025-09-23 15:21:01
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Revisiting Barrett's Esophagus || Endoscopic Treatments: Photodynamic Therapy
摘要： Photodynamic therapy (PDT) is a technique developed in 1990 for reducing the severity of tumor symptoms and cancer size. It acts through a non-thermal mechanism utilizing the activation of a photosensitizer—administrated by intravenous, topical, or oral route—with a specific wavelength of light. The excited photosensitizer generates oxygen radicals which induces localized necrosis and cellular damage in the site of photoactivation. Site and depth of injury depended on several factors, including oxygen concentration, type of sensitizing agent, waiting time between dosing and light stimulation, energy per unit area, intensity of light dosimetry, wavelength, and time of irradiation. PDT may be used in the tissues accessible to light exposure, such as skin, retina, bronchial tree, and the gastrointestinal tract, for either palliative approach (namely lumen obstruction by lung and esophageal tract cancer) or curative therapy. In the gastrointestinal tract, PDT is thought to be effective in the treatment of Barrett’s esophagus with high-grade dysplasia. Further investigational applications include palliative approach to unresectable cholangiocarcinoma and treatment of duodenal or colon adenomas associated to FAP syndrome. Finally, there are few data on ablation of gastric superficial tumors. This review focused on PDT tools, indications, limits, and contraindications in the treatment of Barrett’s esophagus.
关键词： Light,Barrett’s esophagus,Gastrointestinal tract,Photosensitizer,Photodynamic therapy
更新于2025-09-23 15:21:01
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Tuning the Color Palette of Semi-Transparent Solar Cells via Lateral ??-Extension of Polycyclic Heteroaromatics of Donora??Acceptor Dyes
摘要： Durable solar cells with tunable color and diaphaneity are very promising for building integrated photovoltaic applications. In this paper we employ donor–acceptor organic dyes U3, U4, U5, and R6 featured by polycyclic heteroaromatics 6,12-dihydroindeno[1,2-b]indeno[2',1':4,5]thieno[2,3-d]thiophene (IT2), 7,15-dihydrobenzo[6',7']indeno[2',1':4,5]thieno[3,2-b]benzo[6,7]indeno[2,1-d]thiophene (BIT2), 7,15-dihydrophenaleno[1,2-b]phenaleno[2',1':4,5]thieno[2,3-d]thiophene (PT2), and 9,19-dihydrobenzo[1',10']phenanthro[3',4':4,5]thieno[3,2-b]benzo[1,10]phenanthro[3,4-d]thiophene (BPT2) to fabricate semi-transparent dye-sensitized solar cells (DSSCs). The U3, U4, U5, and R6 based cells are goldenrod, crimson, red, and sapphire blue, with power conversion efficiencies of 3.5%, 8.2%, 7.6, and 10.1% at the AM1.5G conditions. Density functional theory calculation and voltammetric measurement reveal that lateral π-extension of polycyclic heteroaromatic brings forth a downward displacement of lowest unoccupied molecular orbital, affording a high molar extinction coefficient, low-energy gap blue dye. Femtosecond fluorescence decay measurements of dyed titania and alumina films unravel the electron injection yields of photo-excited dye molecules, which are well correlated with the maximal values of external quantum efficiencies of DSSCs. After 1,000 h full sunlight soaking at 60 oC, the red and blue DSSCs exhibit stable photocurrents, owing to the strong bonding and photochemical stability of dye molecules adsorbed on the surface of titania as well as the retention of close-to-unity electron collection yield.
关键词： electron injection,durability,tunable color,semi-transparent solar cell,lateral π-extension,photosensitizer
更新于2025-09-23 15:19:57
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Unsymmetrical Small Molecules for Broadband Photoresponse and Efficient Charge Transport in Organic Phototransistors
摘要： Organic photosensitizers have been investigated as effective light sensing elements that can promote strong absorption with high field-effect mobility in organic phototransistors (OPTs). In this study, a novel organic photosensitizer is synthesized to demonstrate broadband photoresponse with enhanced electrical performance. An unsymmetrical small molecule of a solubilizing donor(Dsol)-acceptor(A)-dye donor(Ddye) type connected with twisted conjugation system is designed for broadband detection (ranging from 250 nm to 700 nm). This molecule has high solubility, thereby facilitating the formation of uniformly dispersed nanoparticles in an insulating polymer matrix, which is deposited on top of OPT semiconductors by a simple solution process. The broadband photodetection shown by the organic photosensitizer is realized with improved mobility by close to an order of magnitude and high on/off current ratio (~105) of the organic semiconductor. Furthermore, p-type charge transport behavior in the channel of the OPT is enhanced through the intrinsic electron-accepting ability of the organic photosensitizer, caused by the unique molecular configuration. These structural properties of organic photosensitizers contribute to an improvement in broadband photosensing systems with new optoelectronic properties and functionalities.
关键词： Photosensitizer,Surface doping,Broadband detection,Phototransistor,Charge trap
更新于2025-09-23 15:19:57
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Nucleus-targeted organoiridium-albumin conjugate for photoactivated cancer therapy
摘要： A novel organoiridium-albumin bioconjugate (Ir1-HSA) was synthesized via reaction of a pendant maleimide ligand with human serum albumin. The phosphorescence of Ir1-HSA was enhanced significantly compared to the parent complex Ir1. The long phosphorescence lifetime and high 1O2 quantum yield of Ir1-HSA are highly favourable properties for photodynamic therapy. Ir1-HSA mainly accumulated in the nucleus of living cancer cells and showed remarkable photocytotoxicity against a range of cancer cell lines and tumor spheroids (light IC50; 0.8-5 μM, photo-cytotoxicity index PI = 40-60) while remaining non-toxic to normal cells and normal cell spheroids, even after photo-irradiation. This nucleus-targeting organoiridium-albumin is a strong candidate photosensitizer for anticancer photodynamic therapy.
关键词： Photodynamic therapy,Photosensitizer,Albumin,Organoiridium
更新于2025-09-23 15:19:57
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Heavy-atom-free charge transfer photosensitizers: Tuning the efficiency of BODIPY in singlet oxygen generation via intramolecular electron donor-acceptor interaction
摘要： To test the tunability of charge transfer (CT)-based BODIPY photosensitizers in generating singlet oxygen (1D g), twelve meso-phenyl-BODIPY (donor-acceptor) type compounds have been synthesized and fully characterized, in which the phenyl moiety is modified with respective 0, 1, 2 and 3 methoxy groups to increase its electron-donating ability. The UV-Vis absorption spectra, fluorescence emission spectra, fluorescence quantum yield, fluorescence lifetime, excited triplet state formation, and singlet oxygen formation properties are measured. DFT quantum chemical computation is also carried out to explain the experiments. The occurrence of intra-molecular CT is confirmed by UV-Vis absorption, fluorescence properties and quantum chemical computation. The triplet excited state formation is evidenced by laser flash photolysis technique. The quantitative photosensitized singlet oxygen formation is demonstrated by DPBF (diphenylisobenzofuran) chemical trapping method. This type of BODIPY CT photosensitizers show good tunability in generating singlet oxygen (1D g). When the number of methoxy group on the donor is increased (so that CT is enhanced), the efficiency of singlet oxygen generation becomes higher from 0.070 to 0.30. When solvent polarity is increased (CT is also enhanced), the efficiency of singlet oxygen generation is also increased significantly. The increase in singlet oxygen generation is accompanied by the decrease in fluorescence quantum yield and fluorescence lifetime values. These facts show that a higher CT efficiency in a simple phenyl-BODIPY donor-acceptor conjugate can lead to significant higher quantum yield of singlet oxygen generation. These results are useful in designing novel CT-based heavy-atom-free photosensitizers for photodynamic therapy of tumor.
关键词： Charge transfer photosensitizer,singlet oxygen,BODIPY,photodynamic therapy
更新于2025-09-19 17:15:36