Influence of the glycosaminoglycan layer on the permeation of hypericin in rat bladders in vivo (original) (raw)
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Journal of Urology, 2005
We investigated the importance of E-cadherin expression on the selective accumulation of hypericin in superficial bladder cancer after intravesical instillation.Spheroids obtained from a panel of 3 transitional cell carcinoma cell lines, namely J-82, RT-4 (American Type Culture Collection, Manassas, Virginia) and RT-112 (German Collection of Micro-organisms and Cell Cultures, Braunschweig, Germany), and normal human urothelial (NHU) cells were incubated with hypericin. Accumulation was examined with fluorescence microscopy. Immunohistochemical staining was used to assess E-cadherin expression.Immunohistochemical staining showed E-cadherin expression in NHU (++), RT-112 (+) and RT-4 (+) spheroids, whereas E-cadherin expression was absent in J-82 spheroids. The highest intraspheroidal hypericin accumulation was observed in transitional cell carcinoma spheroids, whereas limited permeation was seen in NHU spheroids. Taken together the data point to an inverse relationship between E-cadh...
2011
Purpose In this preclinical study, we examined the bio-distribution of hypericin formulated as its water-soluble PVP-hypericin complex in the diVerent layers (urothelium, submucosa, muscle) of a normal rat bladder and a rat bladder bearing a malignant urothelium composed of syngeneic AY-27 tumor cells. The results were compared with the biodistribution of hexaminolevulinate (HAL)-induced pro-toporphyrin IX (PpIX). Methods Freshly prepared PVP-hypericin and HAL solutions were instilled in both normal as well as tumor-bearing rat bladders. Following instillation, bladders were removed and snap frozen in liquid nitrogen. Fluorescence of PVP-hypericin or PpIX-induced HAL was measured in the bladder layers and quantiWed using image analysis software. Results The results of these experiments show that PVP-hypericin (30 M) accumulated about 3.5-fold more in malignant urothelial tissue when compared to normal uro-thelium, whereas PpIX accumulated to the same extent in malignant and normal urothelium, both after intrabladder instillation of 8 or 16 mM HAL. Besides, PVP-hypericin and PpIX accumulated selectively in the urothelium with a tumor-to-muscle ratio of 30.6 for PVP-hypericin and 3.7-8.3 for 16 and 8 mM HAL, respectively. Conclusions This study shows that PVP-hypericin appears to have great potential as a photodynamic agent against non-muscle-invasive bladder cancers after intraves-ical administration, with a limited risk of aVecting the deeper layers of the bladder.
International Journal of Cancer, 2003
Whole-bladder wall photodynamic therapy (PDT) is a promising treatment for carcinoma in situ (CIS) and diffuse premalignant changes of the bladder. After the results of our clinical studies showing that intravesical hypericin selectively accumulates in superficial bladder tumors, we investigated the hypericin-PDT efficacy in an AY-27 orthotopic transitional cell carcinoma rat bladder tumor model. After the instillation of hypericin (30 M, 2 hr) in the bladder, tumors were irradiated (25-50 mW/cm 6 -48 J/cm 2 ) using 595 nm laser light. Data demonstrate that light doses of 12-48 J/cm 2 resulted in selective PDT-induced urothelial tumor damage without damaging detrusor musculature. Histological assessment of bladder sections 2 days after PDT showed tumor destruction, with tumor cells shrinking and detaching from the bladder wall. There were tumor regrowth 1-3 weeks after treatment. The in vivo/in vitro clonogenic assay results revealed up to 98% of tumor cell kill by hypericin PDT. In conclusion, hypericin PDT can be used to safely induce a selective urothelial tumor damage without damaging detrusor musculature, when optimum hypericin concentration and light fluences are used. A small percentage (2-5%) of tumor cells that survive the photodynamic treatment resulting in tumor regrowth after a prolonged period of time is likely due to oxygen depletion during light irradiation.
Restoring Barrier Function to Acid Damaged Bladder by Intravesical Chondroitin Sulfate
Journal of Urology, 2009
Chondroitin sulfate (Stellar Pharmaceuticals, London, Ontario, Canada), which is less expensive and more inert than heparinoids, hyaluronan or pentosan polysulfate, has been introduced to restore the barrier function lost due to epithelial dysfunction in interstitial cystitis cases. To our knowledge chondroitin sulfate binding to damaged bladder as a function of the urinary pH range, its efficacy in restoring the bladder permeability barrier and the capacity of the damaged bladder to bind chondroitin sulfate have not been determined previously.Chondroitin sulfate binding to bladder urothelium was investigated quantitatively using chondroitin sulfate highly labeled with Texas Red® and quantitative fluorescence microscopy in a mouse model of urothelial acid damage. The efficacy of restoring barrier function was determined using the passage of intravesically instilled 86Rb, a potassium ion mimetic, through the urothelium into the bloodstream in a rat model of bladder damage. The binding capacity of acid damaged bladder was determined by fluorometry.Chondroitin sulfate bound tightly and exclusively to the mouse bladder surface damaged by acid but showed only minimal binding to undamaged bladder. There was no systematic variation in pH. The model showed some variability in the degree of damage induced. In rats chondroitin sulfate instillation restored permeability to 86Rb to control levels. Binding was saturable at a mean ± SEM 0.67 ± 0.13 mg/cm2 of the bladder surface.Chondroitin sulfate binds preferentially to damaged urothelium and restores the impermeability barrier. This suggests that the glycosaminoglycan layer is a major contributor to bladder urothelial impermeability. As determined by binding capacity, the dose applied in humans in Canada (400 mg per instillation) is sufficient to achieve maximum efficacy.
European Journal of Pharmaceutics and Biopharmaceutics, 2005
In the present study, the systemic absorption of hypericin was investigated after intravesical instillation of the compound in nine patients with superficial transitional cell carcinoma (TCC) bladder tumors. Hypericin (8 mM) was instilled in the bladder for 2-3 h before photodynamic diagnosis of bladder tumors. Blood was then collected from a peripheral vein 1 h after termination of the instillation. Solid phase extraction with ammonium acetate buffer and methanol was used to extract hypericin from the plasma. A reversed-phase high performance liquid chromatographic method with fluorescence detection was used to identify and quantify hypericin in the extracts from plasma samples. Analysis of standard plasma samples, which were spiked with known amounts of hypericin, indicated that the pH of the buffer was a determining factor in the extraction yield. The results obtained using ammonium buffer (pH 3.5) and methanol showed the mean extraction recovery of hypericin to be 64% (RSDZ12%, nZ6). The limits of detection and quantification were 6 and 20 nM, respectively. Extraction and analysis of the plasma of patients after intravesical administration showed hypericin concentrations below the detection limit (!6 nM). In addition, photodynamic treatment of in vitro cultured HeLa cells incubated with 1-100 nM hypericin concentrations showed that lower concentrations (1-20 nM) of hypericin do not induce significant photocytotoxic effects. Taken together, these results imply that photosensitization or other systemic side effects in patients are not to be expected after photodynamic diagnosis of TCC bladder tumors with hypericin.
Urinary glycosaminoglycan excretion as a biochemical marker in patients with bladder carcinoma
Cancer research, 1981
Urinary glycosaminoglycan excretion was examined in 25 individuals with bladder cancer in comparison to glycosaminoglycan excretion by eight normal individuals. Urinary glycosaminoglycan was isolated by gel filtration and quantified as macromolecular uronate concentration. Electrophoresis in calcium acetate and densitometry of Alcian blue-stained electrophoretograms were used to separate and quantify the relative amounts of individual glycosaminoglycans. Elevated excretion of macromolecular uronate was noted in 53% of the cancer cases. The highest levels were found among individuals with metastatic disease. Three electrophoretic bands were always detected in the control and cancer groups: chondroitin sulfate, heparan sulfate (both confirmed by chemical and enzymatic degradation), and a third band (Band 1) of unknown composition. A fourth band, corresponding to dermatan sulfate, was seen in some high-grade metastatic tumors. Band 1 excretion was elevated in a significant fraction of ...