Comparison of intravenous and intravesical administration of chloro-aluminum sulfonated phthalocyanine for photodynamic treatment in a rat bladder cancer model

Establishment of an optimized orthotopic bladder cancer model in mice

BACKGROUND

Bladder cancer (BC) is one of the most common malignancies of the genitourinary system. Animal models offer an important tool to explore tumour initiation, progression, and therapeutic mechanisms. Our aim is to construct an optimized orthotopic BC model which is predictable, reproducible, and convenient.

METHODS

The optimized orthotopic BC model was constructed in male C57BL/6 mice utilizing microsyringes to inoculate them with a murine BC cell line (MB49). Anesthetised mice were inoculated with an MB49 cell suspension (10 µL) at approximately 5 × 10⁶/mL. The whole process of modelling was observed and monitored every 3 days for 21 days utilizing HE staining and transabdominal ultrasonography (TUS).

RESULTS

In this study, the model showed excellent success rates for tumour formation (96.67%) and metastatic rate (89.66%). Compared to the control group (sham operation), mice in the modelling group had serous cachexia, visible haematuresis and weight loss (all P < 0.05). The lungs, liver, ureter and kidneys were found to have tumour metastasis. Moreover, the average survival time (19.73 ± 1.69 d) of modelling mice was significantly shorter than that of the control mice (P < 0.05), which remained alive.

CONCLUSION

Our study established a method using microsyringes to inject murine BC cells into the bladder wall, creating a stable transplantable BC model in mice.

Glypican-1 as a target for fluorescence molecular imaging of bladder cancer

OBJECTIVES

To investigate whether anti-glypican-1 antibody Miltuximab conjugated with near-infrared dye IRDye800CW can be used for in vivo fluorescence imaging of urothelial carcinoma.

METHODS

The conjugate, Miltuximab-IRDye800CW, was produced and characterized by size exclusion chromatography and flow cytometry with glypican-1-expressing cells. Balb/c nude mice bearing subcutaneous urothelial carcinoma xenografts were intravenously injected with Miltuximab-IRDye800CW or control IgG-IRDye800CW and imaged daily by fluorescence imaging. After 10 days, tumors and major organs were collected for ex vivo study of the conjugate biodistribution, including its accumulation in the tumor.

RESULTS

The intravenous injection of Miltuximab-IRDye800CW to tumor-bearing mice showed its specific accumulation in the tumors with the tumor-to-background ratio of 12.7 ± 2.4, which was significantly higher than that in the control group (4.6 ± 0.9, P < 0.005). The ex vivo imaging was consistent with the in vivo findings, with tumors from the mice injected with Miltuximab-IRDye800CW being significantly brighter than the organs or the control tumors.

CONCLUSIONS

The highly specific accumulation and retention of Miltuximab-IRDye800CW in glypican-1-expressing tumors in vivo shows its high potential for fluorescence imaging of urothelial carcinoma and warrants its further investigation toward clinical translation.

A new method of establishing orthotopic bladder transplantable tumor in mice

Objective

The present study aims to find a convenient, rapid, and stable method to establish bladder tumor in mice.

Methods

Female Balb/C-nu-nu nude mice (or female T739 mice) were narcotized by sodium pentobarbital at a dosage of 60 mg/kg. The stylet of the 24# venous retention needles was bent in a 5° to 7° angle at a distance of 15 mm from the needlepoint to form a circle with 2.61 mm to 3.66 mm radius when the stylet is rotated. The pipe casing was lubricated with liquid paraffin, and inserted into the bladder cavity. The drift angle stylet was inserted into the pipe casing slowly, rotated for five times, and then pulled out. A cell suspension (0.1 mL) of approximately 1×10⁶ T24 cells (or BTT cells) was then injected immediately.

Results

A total of 60 T739 mice and 60 Balb/C-nu-nu nude mice were inoculated with BTT cells and T24 cells, respectively. The bladder tumor incidence and the average survival time of the tumor-bearing mice were 100% and (26.69±9.24) d and 100% and (34.59±9.8) d for the T739 mice and Balb/C-nu-nu nude mice, respectively.

Conclusions

Using the drift angle stylet to injure the mucous membrane of the urinary bladder can establish a stable bladder transplantable tumor model in mice.

Terapia fotodinâmica com ftalocianina de zinco tópica: avaliação da intensidade de fluorescência, absorção cutânea, alterações histológicas e imuno-histoquímicas na pele do modelo animal

FUNDAMENTOS - Ftalocianinas são promissores agentes fotossensibilizadores na terapia fotodinâmica (TFD). OBJETIVOS - Avaliar intervalos, veículos e a incorporação de promotor de absorção na formulação tópica da ftalocianina de zinco (FC-Zn). Avaliar alterações macro e micromorfológicas e a expressão de Fas promovidas pela TFD com FC-Zn tópica no modelo murino. MÉTODOS - Por meio da espectrometria de fluorescência, foram avaliadas combinações de diferentes períodos de oclusão tópica das formulações gel ou emulsão de FC-Zn (1mg/dl), com ou sem monoleína 5%, no dorso do camundongo hairless. Após oito horas das diferentes formulações, os camundongos foram expostos ao laser de diodo de 670nm, dose de 50J/cm-². RESULTADOS - A fluorescência foi discretamente superior após oito horas e com a emulsão nos intervalos de uma, duas e quatro horas de oclusão. A intensidade do edema e da erosão correspondeu à necrose da epiderme e à imunoexpressão de Fas nos cortes histológicos de pele. CONCLUSÕES - Os achados indicam a ação fotodinâmica promovida pela interação entre FC-Zn e fonte de luz de 670nm. As alterações macro e micromorfológicas foram correspondentes e mais substanciais com a emulsão FC-Zn e monoleína, sugerindo a acentuação dos efeitos com essa formulação. A imunoexpressão de Fas e as alterações histológicas sugeriram a apoptose como mecanismo de morte celular na TFD com FC-Zn tópica.

Transferrin-Conjugated Liposome Targeting of Photosensitizer AlPcS4 to Rat Bladder Carcinoma Cells

BACKGROUND

The efficacy and safety of photodynamic therapy for superficial bladder cancer depend on tumor-selective accumulation of the photosensitizer. Bladder transitional-cell carcinoma cells overexpress the transferrin receptor on their surface. We examined whether transferrin-mediated liposomal targeting of the photosensitizer aluminum phthalocyanine tetrasulfonate (AlPcS4) is an effective strategy to attain tumor-selective accumulation of this compound when applied intravesically.

METHODS

AlPcS4 was stably encapsulated in unconjugated liposomes (Lip-AlPcS4) or transferrin-conjugated liposomes (Tf-Lip-AlPcS4). The accumulation of free AlPcS4, Lip-AlPcS4, and Tf-Lip-AlPcS4 in human AY-27 transitional-cell carcinoma cells and in an orthotopic rat bladder tumor model was visualized by fluorescence microscopy. In vitro AlPcS4 accumulation was quantified by fluorescence measurements following drug extraction, and the photodynamic efficacy of AlPcS4 was measured in a clonogenic assay. All statistical tests were two-sided.

RESULTS

AY-27 cells incubated with Tf-Lip-AlPcS4 had much higher intracellular AlPcS4 levels than AY-27 cells incubated with Lip-AlPcS4 (384.1 versus 3.7 microM; difference = 380.4 microM, 95% CI = 219.4 to 541.3; P = .0095). Among rats bearing AY-27 cell-derived bladder tumors, intravesical instillation with Tf-Lip-AlPcS4 resulted in mean AlPcS4 fluorescence in tumoral tissue, normal urothelium, and submucosa/muscle of 77.9 fluorescence units (fu) (95% CI = 69.1 to 86.8 fu), 4.3 fu (95% CI = 4.0 to 4.5 fu), and 1.0 (95% CI = 0.1 to 1.9 fu), respectively, whereas instillation of free AlPcS4 resulted in nonselective accumulation throughout the whole bladder wall, and Lip-AlPcS4 instillation resulted in no tissue accumulation. Photodynamic therapy of AY-27 cells incubated with Lip-AlPcS4 resulted in cell viabilities greater than 90% for all concentrations and incubation times tested; photodynamic therapy of cells incubated with 1 muM Tf-Lip-AlPcS4 or AlPcS4 resulted in cell viabilities of 0.19% (95% CI = 0.02% to 0.36%) and 1.32% (95% CI = 0.46% to 2.19%), respectively. Higher concentrations of either AlPcS4 or Tf-Lip-AlPcS4 resulted in cell kills of more than 3 logs.

CONCLUSIONS

Transferrin-mediated liposomal targeting of photosensitizing drugs is a promising potential tool for photodynamic therapy of superficial bladder tumors.

Spatial heterogeneity and temporal kinetics of photosensitizer (AlPcS2) concentration in murine tumors RIF-1 and MTG-B

In this study we compared the photosensitizer concentration in two experimental murine tumors using an in situ fluorescence detection instrument to examine temporal and spatial variations, after intravenous versus intratumor injection. Also, the variations in the estimate as detected by large area sampling and micro-region sampling are compared, in order to determine what the inter-tissue and inter-animal variations are, and how the method of sampling affects this estimate. The latter study was carried out ex vivo in the same tumors, which had been harvested and frozen after in vivo measurements were made. The photosensitizer, disulphonated aluminum phthalocyanine (AlPcS2) was injected either intravenously (IV) or directly into the tumor (ITu), using two murine models, MTG-B (mammary adenocarcinoma) and RIF-1 (radiation-induced fibrosarcoma) grown subcutaneously on the flank. An in situ microsampling fluorescence probe was used to assess photosensitizer concentration, through real-time measurement of the remitted intensity. The photosensitizer concentration was evaluated at 8 time endpoints between 15 min and 48 h post-injection. Inter-tumor and intra-tumor variations were assessed by repeated samples from the tumor tissues. The average photosensitizer level reaches a peak between 3 to 6 h in both tumor and normal tissues using IV administration, but peaks within 1 h following ITu administration. MTG-B tumors demonstrated a factor of 2 higher uptake than RIF-1 tumors. The pharmacokinetic uptake rates of the RIF-1 tumor were 3 times faster than for MTG-B, while there was no statistical difference in their clearance rates. Preferential uptake of AlPcS2 by both tumors compared to contra-lateral flank subcutaneous normal tissue was documented, with ITu injection exceeding IV injection by a factor of 10 in the tumor to normal tissue ratio. Inter-animal standard deviation in the mean fluorescence was near 76% for both routes of administration, but estimates of the variation within tumor were near 16% standard deviation when a large sampling volume was used. In contrast, microscopic intra-tumor standard deviation in the mean estimate was near 76%, with IV injection, indicating that high heterogeneity exists in the photosensitizer concentration on a smaller distance scale. The inter-tumor variation was reduced by ITu injection, but at the expense of increasing intra-tumor variation.

A new method of implanting orthotopic rat bladder tumor for experimental therapies

We developed a model of orthotopic transplantation of bladder tumor cells in female Fischer rats using a new reproducible technique. After first performing the mechanical abrasion of a portion of the bladder urothelium with an Abrader inserted transurethrally via a catheter, we administered a suspension of 5-40 x 10(6) viable AY-27 tumor cells in sterile phosphate-buffered saline to the bladder cavity. This rapidly led to a tumor growth incidence of approximately 100%. The induced bladder tumors grew expansively into the bladder cavity from the surface (mucosa) and gradually invaded the submucosa, muscles, serosa and surrounding tissue (high-stage invasive transitional cell carcinoma). Size and staging were related to the quantity of tumor cells instilled into the bladder cavity. This model matches the characteristics of human bladder tumor more closely than other bladder cancer models induced with tumor cells. Moreover, it presents many advantages: the method is reproducible, tumors grow rapidly, they are directly attached to the bladder surface and they are always located on the bladder wall, in line with the urethra. This proves especially helpful for evaluating chemotherapeutic agents by different means such as in vivo fluorescence spectroscopy, a noninvasive method used in photodynamic therapy, or other methods designed to detect and treat transitional cell carcinoma.

Induction of superficial bladder tumors in the female Fischer 344 rats with AY-27 tumor cells for the study of diffusion and localization of hemoglobin derived components (hematoporphyrin derivative) in view of photochemotherapy

Photochemotherapy (PCT) consists in administration of a photosensitizer and subsequent irradiation of the tumor with visible light. Routinely, the photosensitizer is given intravenously (i.v.), but the major drawback of this procedure is the resulting skin photosensitivity. The goal of our study is to examine whether intravesical (i.b.) instillation of the photosensitizer for PDT of bladder cancer might be feasible in order to target the tumors and to avoid the photosensitization phenomenon. After first studying the biodistribution of hematoporphyrin derivative (HpD) in vivo in the rat bladder, two and four hours after intravesical administration, by fluorescence microscopy, we compared two different methods for the induction of superficial bladder tumors in rats with AY-27 tumor cell line in order to perform the same study on bladder tumors. The best results for the penetration depth of HpD in the normal bladder wall were obtained two hours after the bladder instillation where the photosensitizer was detected only in the bladder surface (urothelium and small part of the chorion). That's why we must choose the most appropriate bladder tumor model in order to obtain superficial bladder tumors that mimic the clinical behavior of superficial bladder cancer in man. Both techniques used in this study gave a high tumor take rate in a short time (> 90%). But we really obtained superficial bladder tumors directly attached to the bladder surface with one of the two methods of tumor induction consisting in the abrasion of the bladder surface prior to the administration of the tumoral cells in the bladder cavity.

In vivo detection of metastatic ovarian cancer by means of 5-aminolevulinic acid-induced fluorescence in a rat model

STUDY OBJECTIVES

To determine the feasibility of macroscopic visualization of small ovarian cancer metastases in vivo by fluorescence after intravenous administration of 5-aminolevulinic acid (ALA); to assess the time after drug injection when fluorescence of small metastases is maximum; and to correlate macroscopic in vivo fluorescence with both microscopic ex vivo fluorescence and histologic findings.

DESIGN

Controlled animal study (Canadian Task Force classification I).

SETTING

University-based facility.

SUBJECTS

Twenty-four healthy, female Fischer rats.

INTERVENTION

Diffuse peritoneal metastatic cancer was induced in Fischer 344 rats by intraperitoneal injection of 1 million syngeneic ovarian cancer cells (NuTu-19). Four weeks after induction ALA100 mg/kg was injected intravenously, and diagnostic laparotomy was performed 1, 3, 6, or 9 hours thereafter.

MEASUREMENTS AND MAIN RESULTS

The peritoneal cavity was illuminated with the Wood's lamp (ultraviolet light). Fluorescence was determined by direct visualization and compared with a calibrated fluorescent disk. Tissues were collected, sectioned, and examined by fluorescence and conventional light microscopy. Within 1 to 3 hours after intravenous injection of ALA, in vivo fluorescence of tumor nodules (diameter 0.4-5.0 mm) was macroscopically visible. Tumor-free peritoneum did not show fluorescence and was significantly distinguishable from cancer nodules. Fluorescence from intestinal tissues was comparable with tumor nodules. Microscopic fluorescence analysis showed similar values for tumor nodules and peritoneum. Stained histologic specimens of peritoneal surface revealed a superficial layer of cancer cells responsible for fluorescence. The time course of the fluorescence curve in the intestine peaked twice, at 1 and 6 hours after ALA injection. Macroscopically fluorescing nodules were histology confirmed as malignant.

CONCLUSIONS

Fluorescence detection of small cancer nodules after intravenous injection of ALA is feasible for nodules smaller than 0.5 mm on the peritoneum. One to 3 hours after drug injection is optimal for diagnosis of metastases.

Aminolevulinic acid for photodynamic therapy of bladder carcinoma cells

A new concept in photosensitizing tumor cells is photosensitizer synthesis in situ. Aminolevulinic acid (ALA) is a precursor of protoporphyrin IX (PP IX), a potent photosensitizer. The goal of our study was to examine dark toxicity, phototoxic potential, metabolism of ALA and morphological alterations in Waf bladder cancer cells. Dark toxicity of Waf cells was observed after incubation with ALA, beginning at a concentration of 15 mM. Photodynamic treatment with ALA at concentrations of 1, 5 and 10 mM showed a drug- and light-dose-dependent cell survival rate in comparison to a control group. Two incubation times of 3.5 and 5.5 h were compared for cell survival. After a longer incubation time of 5.5 h, cell survival was decreased in all experiments; this is consistent with our extraction data where higher fluorescence was found after 5.5 than after 3.5 h. The results show that ALA-induced photosensitization has a high potential for photodynamic therapy (PDT) of superficial bladder carcinoma.

Photodynamic efficiency of liposome-administered tetramethyl hematoporphyrin in two human bladder cancer cell lines

The main problems presented by superficial bladder carcinoma, its high recurrence rate and multifocal appearance, require treatment of the bladder as a whole. Photodynamic therapy (PDT) is one such experimental treatment for superficial bladder carcinoma, involving the administration of a photosensitizer that accumulates in the tumor tissue, and subsequent irradiation of the tumor with light. Since the photosensitizers used in PDT suffer from several drawbacks, new photosensitizers are being sought. Drug delivery systems are also being investigated for the administration of hydrophobic photosensitizers and enhancement of photodynamic efficiency and tumor selectivity. In this study we examined a new photosensitizer, tetramethyl hematoporphyrin (TMHP), in two human bladder cancer cell lines. In the first pair of the experiments, TMHP was bound to unilamellar liposomes. Cellular uptake, dark toxicity and photodynamic efficiency were then studied. Fluorescence microscopy showed TMHP localization in the cytoplasm in a perinuclear region, sparing the nucleus. Dark toxicity occurred after incubation of cells with TMHP above a concentration of 20 micrograms/ml. Irradiation was carried out using an argon-pumped dye laser emitting a wavelength of 630 nm at a fluence of 3.6 and 7.2 J/cm2. Before irradiation, cells were incubated with TMHP at concentrations of 2.5 and 5 micrograms/ml for 1 h. Cell survival rates after incubation with 5 micrograms/ml TMHP and irradiation at 7.2 J/cm2 were 15.7% of control cells for Rec and 4.5% for Waf cells. Uptake studies showed a higher intracellular TMHP concentration in Waf than in Rec cells. This correlates with the higher PDT efficiency seen in Waf cells.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of direct and liposomal antibody conjugates of sulfonated aluminum phthalocyanines for selective photoimmunotherapy of human bladder carcinoma

There is a need to improve the selectivity of photodynamic therapy and for better targeting of tumor cells within specific tumor compartments. Selective in vitro phototoxicity of a human bladder carcinoma cell line 647V has been achieved by targeting sulfonated aluminum phthalocyanines (AlSPc) with monoclonal antibodies. Aluminum tetra-3 sulfonyl chloride phthalocyanine (PC) or rhodamine sulfonyl chloride were directly coupled to antibodies by a sulfonamide linkage and AlSPc or carboxyfluorescein were encapsulated in liposomes of the small unilamellar vesicle type (SUV) bearing antibody. Antibody E7 (IgM subclass), which recognized an antigenic determinant expressed on 647V but was absent on T24 a control human bladder carcinoma cell line, and a control IgM antibody were used. The effects of the two types of conjugate were compared. Immunofluorescence studies on living cells demonstrated specific cell surface localization of conjugates at 4 degrees C and internalization at 37 degrees C. Phototoxicity was measured by 3-(4,5-dimethylthiazol-2-5-diphenyltetrazolium) bromide assay after exposing AlSPc-sensitized cells to red light. Significant AlSPc dose-dependent phototoxicity of the order 4 degrees C < 4 degrees C plus 37 degrees C < 37 degrees C was observed with E7-SUV and E7-PC in the range 1-8 microM AlSPc. At equimolar AlSPc doses absolute toxicity was similar for the two conjugate types, but at equimolar antibody doses, the liposomal conjugate was more effective by up to 13-fold. Addition of urine during illumination decreased toxicity, which was attributed to the presence of protective elements. The results suggest that photosensitizers such as AlSPc could be used for antibody-directed therapy and in particular for selectively damaging tumor cells of the epithelial cell compartment in bladder carcinoma by intrabladder administration. The therapeutic ratio, which takes into account both specific and nonspecific toxicity, was greater for the liposome conjugate than for the direct conjugate indicating their greater suitability for in vivo instillation.

Photoimmunotherapy and biodistribution with an OC125-chlorin immunoconjugate in an in vivo murine ovarian cancer model

Photodynamic therapy (PDT) is an experimental approach to the treatment of neoplasms in which photosensitisers (PSs) accumulated in malignant tissues are photoactivated with appropriate wavelengths of light. The target specificity of PSs may be improved by linking them with carrier macromolecules such as monoclonal antibodies (MAbs). OC125 is a murine MAb that recognises the antigen CA 125, which is expressed on 80% of non-mucinous ovarian tumours. A chlorin derivative conjugated to OC125 was shown to be selectively phototoxic to ovarian cancer and other CA 125-positive cells in vitro and ex vivo. We now report in vivo studies using an ascitic Balb/c nude mouse ovarian cancer model. Ascites was induced by intraperitoneal injection of cells from the human ovarian cancer cell line NIH:OVCAR3. Six weeks after injection, when the animals had developed ascites, biodistribution studies were carried out by injecting the immunoconjugate (IC) or free PS intraperitoneally and sacrificing the animals at 3, 6, 12, 24, 48, 72 and 168 h later. The PS was quantitated by extraction and fluorescence spectroscopy. For both the IC and free PS, peak tumour concentrations were reached at 24 h; however, the absolute concentrations for the IC were always higher (2- to 3-fold) than the free PS. Tumour to non-tumour ratios at 24 h for the IC were 6.8 for blood, 6.5 for liver, 7.2 for kidney, 5.7 for skin and 3.5 for intestine. Evaluation of viable tumour cells in ascites following in vivo PDT with a single light exposure demonstrated a dose-dependent relationship with fluence and IC concentration. However, there was significant treatment-related toxicity at all fluences. With multiple low-dose treatments, the percentage of viable tumour cells was also significantly reduced and there were no treatment-related deaths. These data suggest that, while photoimmunotherapy remains promising as a new treatment modality for ovarian cancers, careful quantitative dosimetry of both IC and light may need to be combined with multiple treatments (as with radiation therapy and chemotherapy) to control malignant disease yet maintain acceptable toxicity in vivo.

Possible advantages of aluminum-chloro-tetrasulfonated phthalocyanine over hematoporphyrin derivative as a photosensitizer in photodynamic therapy

The potency of aluminum-chloro-tetrasulfonated phthalocyanine (AlS4Pc) as a photosensitizer in photodynamic therapy was evaluated in in vitro and in vivo studies. Compared with hematoporphyrin derivative (HpD), the following advantages of AlS4Pc were revealed: (1) AlS4Pc was less toxic than HpD in vitro without light irradiation. (2) AlS4Pc showed more photodynamic-dependent cytotoxicity and anti-tumor effect in the red area of the spectrum (> 660 nm) at which tissue penetration is high. (3) AlS4Pc appeared to be removed more rapidly from normal tissues such as muscle and skin. (4) AlS4Pc showed less photodynamic-dependent cytotoxicity in vitro and milder cutaneous phototoxicity in vivo with UVA irradiation. On the basis of these observations, AlS4Pc shows considerable promise as a photosensitizer for PDT.