Jonathan Kaufman

Urodynamic and Immunohistochemical Evaluation of Intravesical Botulinum Toxin A Delivery Using Liposomes

PURPOSE Botulinum toxin A (Allergan, Irvine, California) is a high molecular weight neurotoxin used to treat hypersensitive bladder by direct injection to pass the urothelial barrier. We investigated the feasibility of intravesical botulinum toxin A delivery using liposomes (Lipella Pharmaceuticals, Pittsburgh, Pennsylvania), which are phospholipid bilayered vesicles, and evaluated the urodynamic and immunohistochemical effect on acetic acid induced bladder hyperactivity in rats. MATERIALS AND METHODS Liposomes (1 ml), botulinum toxin A (20 U/1 ml saline) or botulinum toxin A encapsulated in liposomes (lipotoxin, that is 20 U botulinum toxin A plus 1 ml liposomes) was administered in the bladder and retained for 1 hour on day 1 after baseline cystometrogram. Continuous cystometrogram was performed on day 1 by filling the bladder with saline and on day 8 by filling the bladder with saline, followed by 0.3% acetic acid. The bladder was then harvested. Cystometrogram parameters, histology, SNAP25 and calcitonin gene-related peptide expression were measured by Western blotting or immunostaining. RESULTS The intercontraction interval was decreased 57.2% and 56.0% after intravesical acetic acid instillation in liposome and botulinum toxin A pretreated rats, respectively. However, rats that received lipotoxin showed a significantly decreased intercontraction interval response (21.1% decrease) to acetic acid instillation but without compromised voiding function. Also, lipotoxin pretreated rats had a better decrease in the inflammatory reaction and SNAP-25 expression, and increase in calcitonin gene-related peptide immunoreactivity than those in liposome or botulinum toxin A pretreated rats. CONCLUSIONS Intravesical lipotoxin administration cleaved SNAP-25, inhibited calcitonin gene-related peptide release from afferent nerve terminals and blocked the acetic acid induced hyperactive bladder. These results support liposomes as an efficient vehicle for delivering botulinum toxin A without injection.

Instillation of liposomes vs dimethyl sulphoxide or pentosan polysulphate for reducing bladder hyperactivity

To investigate the efficacy of intravesical liposomes against dimethyl sulphoxide (DMSO), and pentosan polysulphate (PPS) in reducing chemically induced bladder hyperactivity in rats.

Intravesical immune suppression by liposomal tacrolimus in cyclophosphamide-induced inflammatory cystitis†‡

Potent immunosuppressive effect of tacrolimus has encouraged its topical application for achieving local anti‐inflammatory effect. However, its poor aqueous solubility presents challenges in formulating biocompatible instillations to justify the investigation of liposomes as vehicle for tacrolimus.

Development of Potential Orphan Drug Therapy of Intravesical Liposomal Tacrolimus for Hemorrhagic Cystitis Due to Increased Local Drug Exposure

PURPOSE The potent immunosuppressive effect of systemic tacrolimus is limited by the high incidence of severe adverse effects, including nephrotoxicity and hypertension. Intravesical application of tacrolimus is hindered by its poor aqueous solubility, justifying the search for novel delivery platforms such as liposomes. We evaluated the pharmacokinetics of tacrolimus encapsulated in liposomes (lipo-tacrolimus), which is being developed as a potential orphan drug indication for hemorrhagic cystitis. MATERIALS AND METHODS A single dose of lipo-tacrolimus was instilled in the bladder with the rat under anesthesia. Also, tacrolimus was instilled intravesically or injected intraperitoneally in other rat groups. The tacrolimus dose was constant in all formulations at 200 μg/ml. At different times blood, urine and bladder samples were collected and stored at -80C until analysis. Tacrolimus levels in samples were analyzed using microparticle enzyme immunoassay II. RESULTS The AUC of lipo-tacrolimus in serum at 0 to 24 hours was significantly lower than that of tacrolimus instillation or injection. Noncompartmental pharmacokinetic data analysis revealed maximum concentration of lipo-tacrolimus and tacrolimus in serum and urine at 1 and at 2 hours, respectively. Urine AUC(0-24) after intravesical administration was significantly higher than in the intraperitoneal group (p <0.05). Bladder tacrolimus AUC(0-24) did not differ significantly between the groups. CONCLUSIONS Single dose pharmacokinetics revealed that bladder instillation of liposome encapsulated tacrolimus significantly decreased systemic exposure to instilled tacrolimus as well as vehicle related toxicity. Intravesical liposomal tacrolimus may be a promising approach as an orphan drug indication for hemorrhagic cystitis.

Advances in Therapeutic Development for Radiation Cystitis

Radiation treatment for pelvic malignancies is typically associated with radiation injury to urinary bladder that can ultimately lead to radiation cystitis (RC). The late sequelae of radiation therapy may take many years to develop and include bothersome storage symptoms such as hematuria, which may be life‐threatening in severe cases of hemorrhagic cystitis. Although no definitive treatment is currently available, various interventions are used for radiation and hemorrhagic cystitis including blood transfusion, bladder irrigation, intravesical instillation of substances such as alum, silver nitrate, prostaglandins or formalin, and fulguration of intravesical bleeding sites and surgery options such as supravesical urinary diversions and cystectomy. Effects of non‐surgical treatments for radiation and hemorrhagic cystitis are of modest success and studies are lacking to control the effects caused by RC. When such measures have proven ineffective, use of bladder botulinum toxin injection has been reported. New therapy, such as intravesical immunosuppression with local tacrolimus formulation is being developed for the treatment of radiation hemorrhagic cystitis.

Novel Therapy with Intravesical Liposomes for Ulcerative Interstitial Cystitis/Painful Bladder Syndrome.

Objectives: A Federal Drug Administration‐approved, compassionate‐use, investigational new drug single‐subject trial was conducted to evaluate the safety and clinical outcomes of intravesical instillation of liposomes in a woman with ulcerative interstitial cystitis/painful bladder syndrome (IC/PBS).

Cystometric Changes in Pressure-guided Acute Distension Rat Model of the Underactive Bladder™

Abstract Objective Acute bladder distension results in pressure ischemia, subsequent reperfusion injury, and ultimately damage to the detrusor. We hypothesize that changes in pressure may be a key factor to damage resulting from over-distension and developed a pressure-guided distension model to evaluate cystometric changes. Materials and Methods Three groups of adult female Sprague Dawley rats (250 g) were used: a sham distended control group, a 3-day (3D) and 7-day (7D) follow-up group after pressure-guided distension. Under pentobarbital anesthesia, the urethra was clamped and saline was infused (0.04 mL/min) under continuous intravesical pressure monitoring. After reaching 120 cmH 2 O pressure, infusion was stopped and clamping was maintained for 30 minutes. For sham distension, all procedures except the saline infusion were done. Results There were no bladder ruptures during distension. Distension volumes needed to achieve the fixed pressure were variable (1.68–2.90 mL), but mean distension volumes were similar between the 3D and 7D groups (2.1 ± 0.1 mL vs. 2.2 ± 0.3 mL). After distension, maximal cystometric capacity and residual urine volume were increased at both time points. Voiding efficiencies were decreased significantly in both the 3D and 7D groups ( p Conclusion Our pressure-guided distension model exhibits cystometric characteristics of bladder decompensation. This model for the underactive bladder™ (UAB) may prove useful to further the development of targeted UAB™ treatments.

Potential Effect of Liposomes and Liposome-Encapsulated Botulinum Toxin and Tacrolimus in the Treatment of Bladder Dysfunction.

Bladder drug delivery via catheter instillation is a widely used treatment for recurrence of superficial bladder cancer. Intravesical instillation of liposomal botulinum toxin has recently shown promise in the treatment of overactive bladder and interstitial cystitis/bladder pain syndrome, and studies of liposomal tacrolimus instillations show promise in the treatment of hemorrhagic cystitis. Liposomes are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core that can encapsulate hydrophilic and hydrophobic drug molecules to be delivered to cells via endocytosis. This review will present new developments on instillations of liposomes and liposome-encapsulated drugs into the urinary bladder for treating lower urinary tract dysfunction.

Novel Contrast Mixture Improves Bladder Wall Contrast For Visualizing Bladder Injury

Here, we tested whether combined contrast-enhanced magnetic resonance imaging (CCE-MRI), using a mixture of gadolinium- and iron oxide-based contrast agents, can segment the bladder wall from the bladder lumen. CCE-MRI relies on the differences in particle size and contrast mechanisms of two agents for improved image contrast. Under isoflurane anesthesia, T1-weighted imaging of adult female Sprague-Dawley rat bladder was performed using standard turbospin echo sequences at 7 Tesla, before and after transurethral instillation of 0.3 ml of single-contrast MRI or CCE-MRI composed of 0.4-64 mM of gadolinium chelate (Gd-DTPA/Gadavist) and 5 mM ferumoxytol. Bladder wall contrast was assessed in the control group exposed to saline and in the bladder injury group exposed to 0.5 ml of protamine sulfate (10 mg/ml) for 30 min. CCE-MRI following instillation of 0.4-4 mM Gd-DTPA and 5 mM ferumoxytol mixture achieved segmentation between the bladder lumen and bladder wall. Hyperintensity in the bladder wall combined with hypointensity in the lumen is consistent with the increased diffusion of the dissolved Gd-DTPA and simultaneous localization of the larger nanoparticles of ferumoxytol in the lumen. The normalized hyperintense signal in the bladder wall increased from 0.46 ± 0.07 in control group to 0.73 ± 0.14 in the protamine sulfate-exposed group (P < 0.0001). CCE-MRI following instillation of contrast mixture identifies bladder wall changes likely associated with bladder injury with improved image contrast.

MP39-10 NOVEL CONTRAST MIXTURE ACHIEVES CONTRAST RESOLUTION OF HUMAN BLADDER WALL SUITABLE FOR T1 MAPPING: APPLICATIONS IN INTERSTITIAL CYSTITIS (IC) AND BEYOND

Purpose Instillation of novel contrast mixture (NCM) was recently shown to improve the contrast resolution of rat bladder wall with high contrast-to-noise ratio (CNR). Here, the clinical safety and the feasibility of NCM-enhanced MRI to achieve artifact-free visualization of human bladder wall suitable for quantitative measurement of the magnetic resonance (MR) longitudinal relaxation time (T1) was assessed.