phytochlorin and Urinary-Bladder-Neoplasms

An emerging class of targeted therapy relies on light as a spatially and temporally precise stimulus. Photodynamic therapy (PDT) is a clinical example in which optical illumination selectively activates light-sensitive drugs, termed photosensitizers, destroying malignant cells without the side effects associated with systemic treatments such as chemotherapy. Effective clinical application of PDT and other light-based therapies, however, is hindered by challenges in light delivery across biological tissue, which is optically opaque. To target deep regions, current clinical PDT uses optical fibers, but their incompatibility with chronic implantation allows only a single dose of light to be delivered per surgery. Here we report a wireless photonic approach to PDT using a miniaturized (30 mg, 15 mm

Topics: Animals; Chlorophyllides; Dose-Response Relationship, Drug; Electric Power Supplies; Equipment Design; Implants, Experimental; Mice, Inbred C57BL; Miniaturization; Neovascularization, Pathologic; Photochemotherapy; Photosensitizing Agents; Porphyrins; Urinary Bladder Neoplasms; Wireless Technology; Xenograft Model Antitumor Assays

Bladder sparing treatment options for high risk non-muscle invasive blader cancer (NMIBC) after intravesical Bacillus Calmette-Guerin (BCG) failure are limited.. To evaluate photodynamic therapy (PDT) using chlorin e6-polyvinylpyrrolidone (Ce6-PVP) as a bladder sparing therapy for NMIBC refractory to intravesical BCG therapy.. Between July 2004 and June 2009, patients with recurrent NMIBC after induction intravesical BCG therapy were treated with PDT performed with a 665nm laser and light dosimetry of 10-24J/cm(2). The patients underwent cystoscopic surveillance for tumour recurrence post PDT. Post treatment lower urinary tract symptoms and bladder capacity were also monitored. Serum and urine samples were collected for spectrometric quantification of photosensitizer levels.. Five patients underwent PDT, with a total of seven treatments performed. One patient received intravenous Ce6-PVP, while the rest received intravesical Ce6-PVP.The median age was 80 years (mean 79 years, range 72-88 years). There were three patients with primary CIS of the bladder and two with T1 high grade TCC and CIS of the bladder. At a median follow-up of 29 months (mean 25 months, range 6-36 months), two patients were disease free, two patients developed recurrence and one patient progressed to muscle invasive disease. There were no immediate adverse effects. The patient receiving intravenous Ce6-PVP developed an enterovesical fistula 16 months post PDT.. Despite being a small pilot study, intravesical Ce6-PVP mediated PDT is a feasible bladder sparing treatment option for recurrent high risk non-muscle invasive bladder carcinoma in selected individuals.

Topics: Administration, Intravesical; Aged; Aged, 80 and over; BCG Vaccine; Carcinoma in Situ; Carcinoma, Transitional Cell; Chlorophyllides; Feasibility Studies; Female; Humans; Injections, Intravenous; Male; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Photochemotherapy; Porphyrins; Povidone; Protoporphyrins; Radiation-Sensitizing Agents; Treatment Failure; Urinary Bladder Neoplasms

Topics: Carcinoma in Situ; Carcinoma, Transitional Cell; Chlorophyllides; Humans; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Photochemotherapy; Porphyrins; Povidone; Protoporphyrins; Radiation-Sensitizing Agents; Urinary Bladder Neoplasms

Photosensitizer based fluorescence imaging and spectroscopy is fast becoming a promising approach for cancer detection. The purpose of this study was to examine the use of the photosensitizer chlorin e6 (Ce6) formulated in polyvinylpyrrolidone (PVP) as a potential exogenous fluorophore for fluorescence imaging and spectroscopic detection of human cancer tissue xenografted in preclinical models as well as in a patient.. Fluorescence imaging was performed on MGH human bladder tumor xenografted on both the chick chorioallantoic membrane (CAM) and the murine model using a fluorescence endoscopy imaging system. In addition, fiber optic based fluorescence spectroscopy was performed on tumors and various normal organs in the same mice to validate the macroscopic images. In one patient, fluorescence imaging was performed on angiosarcoma lesions and normal skin in conjunction with fluorescence spectroscopy to validate Ce6-PVP induced fluorescence visual assessment of the lesions.. Margins of tumor xenografts in the CAM model were clearly outlined under fluorescence imaging. Ce6-PVP-induced fluorescence imaging yielded a specificity of 83% on the CAM model. In mice, fluorescence intensity of Ce6-PVP was higher in bladder tumor compared to adjacent muscle and normal bladder. Clinical results confirmed that fluorescence imaging clearly captured the fluorescence of Ce6-PVP in angiosarcoma lesions and good correlation was found between fluorescence imaging and spectral measurement in the patient.. Combination of Ce6-PVP induced fluorescence imaging and spectroscopy could allow for optical detection and discrimination between cancer and the surrounding normal tissues. Ce6-PVP seems to be a promising fluorophore for fluorescence diagnosis of cancer.

Topics: Animals; Cell Line, Tumor; Chick Embryo; Chlorophyllides; Chorioallantoic Membrane; Disease Models, Animal; Luminescent Measurements; Mice; Mice, Inbred C57BL; Mice, Nude; Microscopy, Fluorescence; Porphyrins; Povidone; Protoporphyrins; Sensitivity and Specificity; Spectrometry, Fluorescence; Urinary Bladder Neoplasms

We have determined the influences of polyvinylpyrrolidone (PVP) on the topical delivery of chlorin e6 (Ce6) in malignant bladder cells. The chick chorioallantoic membrane (CAM) was used to model the tumor spheroids that resemble small residual bladder tumors prior to vascularization. Macroscopic fluorescence imaging showed that Ce6-PVP-induced fluorescence had a higher sensitivity and specificity for delineating tumor from the adjacent normal CAM compared to Ce6 alone. Nonlinear regression analyses have shown that Ce6-PVP has a longer half-life in the tumor compared to Ce6. The uptake ratio of Ce6-PVP was found to have a 2-fold increase across the CAM when compared to that of Ce6, indicating that PVP was able to facilitate diffusion of Ce6 across the membrane. Confocal laser scanning microscopy further confirmed that Ce6-PVP has better penetration in the CAM as well as in the tumor cells compared to Ce6. The present work contributes to our understanding of the Ce6-PVP drug-polymer system by demonstrating for the first time that the presence of PVP facilitates the transport of Ce6 across the chorioallantoic membrane.

Topics: Animals; Biological Transport; Cell Line, Tumor; Cell Membrane Permeability; Chick Embryo; Chlorophyllides; Chorioallantoic Membrane; Diffusion; Humans; Neoplasm Transplantation; Photochemotherapy; Photosensitizing Agents; Porphyrins; Povidone; Spheroids, Cellular; Transplantation, Heterologous; Urinary Bladder Neoplasms

The use of fluorescence diagnosis as a modern cancer diagnostic modality is rapidly gaining importance in the field of urology. It is based on the detection of distinctive light emission of tissues sensitized by fluorescent dyes, commonly referred to as photosensitizers, after irradiation with a specific light source. Therefore, the search for specific fluorescent dyes with high sensitivity and specificity for bladder cancer is constantly being sought after. The aim of this study is to investigate the use of a new formulation consisting a mixture of chlorin e6 and polyvinylpyrrolidone (Ce6-PVP) for the detection of human bladder cancer cells (MGH) implanted on the chick chorioallantoic membrane (CAM) model. Uptake kinetics studies were quantitatively determined for both systemic and topical administrations of Ce6-PVP to the normal CAM as well as the MGH human bladder tumor implanted on CAM using fluorescence imaging technique. Rapid elimination of Ce6-PVP was displayed following topical application compared to systemic administration in the normal CAM system. Ce6-PVP was found to localize selectively in the xenografted bladder tumor in contrast to the CAM tissue. Neither dark toxicity nor irritancy was observed on the CAM tissue at the dose of 2 mg/kg Ce6-PVP. In conclusion, the Ce6-PVP formulation appeared to have the potential as a fluorescent marker for fluorescence diagnosis of human bladder cancer.

Topics: Animals; Cell Line, Tumor; Chick Embryo; Chickens; Chlorophyllides; Chorioallantoic Membrane; Diagnostic Imaging; Fluorescence; Fluorometry; Humans; Kinetics; Neoplasm Transplantation; Porphyrins; Povidone; Transplantation, Heterologous; Urinary Bladder Neoplasms

We propose the use of acetoxymethyl esters of pH-sensitive amphipathic photosensitizers (PS) for photodynamic therapy (PDT). These compounds may be applicable for PDT involving endocytosis of lipophilic carriers leading to lysosomal uptake of the esterified PS by target cells. Partial and/or total enzymatic de-esterification may result in the extralysosomal distribution of the photoactive agents, possibly culminating in a multisite photochemical response. We report here the synthesis and properties of chlorin e6 triacetoxymethyl ester (CAME) and pheophorbide a acetoxymethyl ester (PAME). Chlorin e6 and pheophorbide a are photocytotoxic chlorins that possess free carboxylate groups and exhibit optimum wavelengths of excitation substantially red shifted relative to hematoporphyrin derivative. Acetoxymethyl esterification of chlorin e6 and pheophorbide a was accomplished with bromomethyl acetate. High-performance liquid chromatography allowed for the purification of PAME, in 87% purity, and CAME, in 63% yield and 94% purity, as well as the detection of the presumed mono- and diesters of chlorin e6 as transient intermediates in the synthesis of CAME. The ultraviolet-visible absorption, fluorescence excitation and emission, NMR and mass spectra of the chlorin e6 triester are consistent with those expected for CAME. The pH-sensitive amphipathicity of pheophorbide a and chlorin e6 but not CAME was demonstrated using a water/1-octanol partition assay. The production of pheophorbide a from PAME and the sequential formation of the di- and monoesters and free chlorin e6 from CAME, by the action of lysosomal esterases obtained from cancer cells, demonstrate the potential of cellular enzymes to convert the lipophilic esters to pH-sensitive amphipathic PS.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Carcinoma; Chlorophyll; Chlorophyllides; Esterases; Esterification; Esters; Humans; Hydrogen-Ion Concentration; Lysosomes; Photosensitizing Agents; Porphyrins; Solubility; Spectrometry, Fluorescence; Spectrophotometry; Urinary Bladder Neoplasms

Photodynamic therapy is an experimental method of cancer treatment in which a photosensitizer is administered and subsequently the tumor is irradiated with light. Due to problems of prolonged skin phototoxicity with hematoporphyrin derivative, new photosensitizers and methods of localization are being sought. The goal of this study was to compare the photosensitizer chlorin e6 (Ce6) free and bound to 1-micron-diameter microspheres (MS) for phototoxicity, uptake and efflux characteristics, phagocytosis rates in malignant and benign cells, and effects of NaN3, D2O, and buthionine sulfoximine on phototoxic efficacy. Incubation of MGH-U1 human bladder carcinoma cells with Ce6-MS (0.43 microM Ce6-equivalent; 18 h) and subsequent irradiation using an argon laser-pumped dye laser at a radiant exposure of 20 J/cm2 caused 100% cell death 24 h after irradiation. In contrast, MGH-U1 cells incubated with free Ce6 (0.43 microM; 18 h) remained 100% viable 24 h after irradiation at a radiant exposure of up to 50 J/cm2. The presence of D2O during irradiation increased the phototoxicity to MGH-U1 cells, whereas the presence of NaN3 decreased it; these data support an important role for 1O2. Irradiation of MGH-U1 cells in the presence of the glutathione depleter buthionine sulfoximine also increased the phototoxicity, demonstrating a role for intracellular glutathione and possibly free radical intermediates. The cellular uptake of Ce6 was approximately 50 times lower than that of Ce6-MS at equivalent incubation concentrations. Efflux experiments showed that the phototoxicity of Ce6-MS was reduced by 40% for a 5-h washout time as compared to no washout time. In contrast, for free Ce6, the decrease was 95.3% under identical conditions. Because the total intracellular concentration of Ce6-MS after an efflux time of 5 h was only slightly changed, the decreased phototoxicity is attributed to an altered intracellular localization. Confocal laser scanning fluorescence microscopy data appear consistent with this hypothesis although they are not conclusive. The observed patterns were different at 0 and 5 h. Comparison of the phagocytosis rates of Ce6-MS by carcinoma and benign cells showed that on average 20 MS/cell were phagocytosed by MGH-U1 compared with 2.5 and 8.3 in the benign human fibroblasts and keratinocytes, respectively. After incubation with Ce6-MS (0.1 microM; 18 h) and irradiation at 10 J/cm2 the surviving fraction of MGH-U1 cells was 76.3 +/- 0.95% (mean +/- SE) and

Topics: Buthionine Sulfoximine; Cell Line; Cell Survival; Chlorophyllides; Fibroblasts; Humans; Kinetics; Light; Methionine Sulfoximine; Microspheres; Porphyrins; Radiation-Sensitizing Agents; Urinary Bladder Neoplasms

Photodynamic therapy is an experimental modality for treatment of superficial bladder cancer, and consists of the administration of a photosensitizer and subsequent tumor-irradiation with light. Presently hematoporphyrin derivative (HPD) is the only photosensitizer in experimental clinical use in the United States. Because of the high nonspecific phototoxicity of HPD, new methods of photosensitization have been sought. In this study we compared chlorin e6, free and conjugated to 1-micron.-diameter latex microspheres. Phototoxicity was evaluated on MGH-U1 cells derived from a human bladder carcinoma. MGH-U1 cells were preincubated for 18 hours either with free Ce6 (0.43 microM) or Ce6-microspheres (0.43 microM equivalent in Ce6) and irradiated with an argon-laser-pumped dye laser emitting at 659 nm., over the radiant-exposure range of 5-50 J/cm. At 24 hours after light exposure the cells were observed microscopically for morphological alteration and evaluated for cell death by trypan blue exclusion. Cultures incubated with Ce6-microspheres and subsequently irradiated showed morphologic evidence of cell damage, apparent after irradiation with five J/cm. and a light dose dependent decrease in cell survival. In contrast, cells incubated with free Ce6 at the same concentration of 0.43 microM and subsequently irradiated demonstrated neither detectable morphologic alteration nor change in cell survival. Only cells preincubated with free Ce6 at higher concentration showed morphologic changes. Thus, Ce6-microsphere conjugate was much more efficient at inducing photodynamic destruction of bladder carcinoma cells than was free Ce6.

Topics: Carcinoma, Transitional Cell; Cell Line; Cell Survival; Chlorophyllides; Humans; Latex; Microspheres; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Tumor Cells, Cultured; Urinary Bladder Neoplasms