A review of recent developments on micro/nanostructured pharmaceutical systems for intravesical therapy of the bladder cancer

Potential bladder cancer therapeutic delivery systems: a recent update

INTRODUCTION

Bladder Cancer is one of the most expensive cancers to treat due to its high cost of therapy as well as the surveillance expenses incurred to prevent disease recurrence and progression. Thus, there is a strong need to develop safe, efficacious drug formulations with controlled drug release profiles and tumor-targeting potential, for improved therapeutic outcomes of bladder cancer patients.

AREAS COVERED

This review aims to provide an overview of drug formulations that have been studied for potential bladder cancer treatment in the last decade; highlight recent trends in bladder cancer treatment; mention ongoing clinical trials on bladder cancer chemotherapy; detail recently FDA-approved drug products for bladder cancer treatment and identify constraints that have prevented the translation of promising drug formulations from the research laboratory to the clinics.

EXPERT OPINION

This work revealed that surface functionalization of particulate drug delivery systems and incorporating the nanoparticles into in situ gelling systems could facilitate controlled drug release for extended periods, and improve the prognosis of bladder cancer treatment. Future research directions could incorporate multiple drugs into the drug delivery systems to treat advanced stages of the disease. In addition, smart nanomaterials, including photothermal therapies, could be exploited to improve the therapeutic outcomes of bladder cancer patients.

Advancements in nanomedicine: Precision delivery strategies for male pelvic malignancies - Spotlight on prostate and colorectal cancer

BACKGROUND

Pelvic malignancies consistently pose significant global health challenges, adversely affecting the well-being of the male population. It is anticipated that clinicians will continue to confront these cancers in their practice. Nanomedicine offers promising strategies that revolutionize the treatment of male pelvic malignancies by providing precise delivery methods that aim to improve the efficacy of therapeutic outcomes while minimizing side effects. Nanoparticles are designed to encapsulate therapeutic agents and selectively target cancer cells. They can also be loaded with theragnostic agents, enabling multifunctional capabilities.

OBJECTIVE

This review aims to summarize the latest nanomedicine research into clinical applications, focusing on nanotechnology-based treatment strategies for male pelvic malignancies, encompassing chemotherapy, radiotherapy, immunotherapy, and other cutting-edge therapies. The review is structured to assist physicians, particularly those with limited knowledge of biochemistry and bioengineering, in comprehending the functionalities and applications of nanomaterials.

METHODS

Multiple databases, including PubMed, the National Library of Medicine, and Embase, were utilized to locate and review recently published articles on advancements in nano-drug delivery for prostate and colorectal cancers.

CONCLUSION

Nanomedicine possesses considerable potential in improving therapeutic outcomes and reducing adverse effects for male pelvic malignancies. Through precision delivery methods, this emerging field presents innovative treatment modalities to address these challenging diseases. Nevertheless, the majority of current studies are in the preclinical phase, with a lack of sufficient evidence to fully understand the precise mechanisms of action, absence of comprehensive pharmacotoxicity profiles, and uncertainty surrounding long-term consequences.

Optimization of PLGA-DSPE hybrid nano-micelles with enhanced hydrophobic capacity for curcumin delivery

Poly (D, L Lactic-co-Glycolic acid) (PLGA) is an FDA-approved polymer. It is distinguished from other biocompatible polymers by its feasibility of production and safety for intravenous cancer tumor targeting. Curcumin (CUR) is a natural molecule with versatile bioactivities including inhibiting the nuclear Factor kappa B (Nf-kB) levels in cancer cells, increased by chemotherapy agents. Our group previously reported a successful decrease in the p65 (RelA) subunit of Nf-kB using 125 µg/ml CUR loaded into PLGA nano-micelles. However, this amount was insufficient to reduce all Nf-kB subunits. This study aimed to increase the hydrophobic capacity of PLGA toward CUR using 1,2-Distearoyl-sn-glycerol-3-phosphoethanolamine (DSPE), an FDA-approved phospholipid. PLGA-DSPE hybrid nano-micelles (HNM) were prepared using two different methods, oil-in-water (OiWa) and film preparation-rehydration (FiRe). The encapsulated CUR was successfully increased to 250 µg/ml using the FiRe method. Physicochemical characterization of CUR-loaded HNM was performed using DLS FT-IR, DSC, and HPLC. In HNM with a size of 156.6 nm, DSPE, incorporated with all functional groups of PLGA, and CUR was trapped in the core of this structure. The release profile of CUR was suitable for targeted cancer therapy and the Encapsulation Efficacy was 92%.

Mucoadhesive gellan gum-based and carboxymethyl cellulose -based hydrogels containing gemcitabine and papain for bladder cancer treatment

Local treatment of bladder cancer faces several limitations such as short residence time or low permeation through urothelium tissue. The aim of this work was to develop patient-friendly mucoadhesive gel formulations combining gemcitabine and the enzyme papain for improved intravesical chemotherapy delivery. Hydrogels based on two different polysaccharides, gellan gum and sodium carboxymethylcellulose (CMC), were prepared with either native papain or papain nanoparticles (nanopapain) to explore for the first time their use as permeability enhancers through bladder tissue. Gel formulations were characterized regarding enzyme stability, rheological behavior, retention on bladder tissue and bioadhesion, drug release properties, permeation capacity, and biocompatibility. After 90 days of storage, the enzyme loaded in the CMC gels retained up to 83.5 ± 4.9 % of its activity in the absence of the drug, and up to 78.1 ± 5.3 with gemcitabine. The gels were mucoadhesive and the enzyme papain showed mucolytic action, which resulted in resistance against washing off from the urothelium and enhanced permeability of gemcitabine in the ex vivo tissue diffusion tests. Native papain shortened lag-time tissue penetration to 0.6 h and enhanced 2-fold drug permeability All formulations demonstrated pseudoplastic behavior and no irritability. Overall, the developed formulations have potential as an upgraded alternative to intravesical therapy for bladder cancer treatment.

A novel bidirectional perfusion-like administered system for NIR-II fluorescence imaging precision diagnosis of bladder cancer

Intravesical instillation has been considered an efficient route for detecting bladder cancer. However, only a small fraction of administered dose permeates into tumor tissues, and insufficient retention time limits their application. In this work, a novel intravesical bidirectional perfusion-like administered mode was developed to improve diagnostic accuracy of bladder tumor imaging. Specifically, the ultrasmall AuPd-P-FA Nanoprobe exhibit excellent NIR-II FL imaging performance due to electronic structure perturbation. Benefiting from the size advantage for kidney metabolism and FA targeting specificity, AuPd-P-FA could effectively administration to bladder tumor. When AuPd-P-FA reached maximum enrichment at 1 h post-injection, the localized and mild thermal energy produced upon laser irradiation activated a phase transition. This thermo-sensitive characteristic could prolong the retention time in bladder and the fluorescence signal could be clearly observed at 6 h post-injection with high accuracy. This novel intravesical bidirectional perfusion-like administered mode is expected to achieve a non-invasive diagnosis of early bladder cancer.

The Progress of Chitosan-Based Nanoparticles for Intravesical Bladder Cancer Treatment

Bladder cancer (BC) is the most frequently occurring cancer of the urinary system, with non-muscle-invasive bladder cancer (NMIBC) accounting for 75-85% of all the bladder cancers. Patients with NMIBC have a good survival rate but are at high risk for tumor recurrence and disease progression. Intravesical instillation of antitumor agents is the standard treatment for NMIBC following transurethral resection of bladder tumors. Chemotherapeutic drugs are broadly employed for bladder cancer treatment, but have limited efficacy due to chemo-resistance and systemic toxicity. Additionally, the periodic voiding of bladder and low permeability of the bladder urothelium impair the retention of drugs, resulting in a weak antitumoral response. Chitosan is a non-toxic and biocompatible polymer which enables better penetration of specific drugs to the deeper cell layers of the bladder as a consequence of temporarily abolishing the barrier function of urothelium, thus offering multifaceted biomedical applications in urinary bladder epithelial. Nowadays, the rapid development of nanoparticles significantly improves the tumor therapy with enhanced drug transport. This review presents an overview on the state of chitosan-based nanoparticles in the field of intravesical bladder cancer treatment.

Nano-BTA: A New Strategy for Intravesical Delivery of Botulinum Toxin A

Botulinum neurotoxin subtype A (BoNT-A) has been part of the urology treatment arsenal since it was first used in the treatment of detrusor-sphincter dyssynergia more than 30 years ago. BoNT-A has been recommended as an effective treatment for neurogenic detrusor overactivity and overactive bladder. However, direct intradetrusor injection of BoNT-A using cystoscopy after anesthesia may cause hematuria, pain, and infection; these adverse events have motivated urologists to find less invasive and more convenient ways to administer BoNT-A. The development of nanotechnology has led to the advancement of intravesical drug delivery. Using versatile nanocarriers to transport BoNT-A across the impermeable urothelium is a promising therapeutic option. In this review, we discuss the effectiveness and feasibility of liposomes, thermosensitive polymeric hydrogels, and hyaluronan-phosphatidylethanolamine as carriers of BoNT-A for intravesical instillation. To date, these carriers have not reached a similar efficacy as intradetrusor injections in long-term observations. Hopefully, researchers will make a breakthrough with new nanomaterials to develop clinical applications in the future.

Current Researches on Nanodrug Delivery Systems in Bladder Cancer Intravesical Chemotherapy

Bladder cancer is one of the most common malignant tumors in urinary system. Intravesical chemotherapy is a common adjuvant therapy after transurethral resection of bladder tumors. However, it has several disadvantages such as low drug penetration rate, short residence time, unsustainable action and inability to release slowly, thus new drug delivery and new modalities in delivery carriers need to be continuously explored. Nano-drug delivery system is a novel way in treatment for bladder cancer that can increase the absorption rate and prolong the duration of drug, as well as sustain the action by controlling drug release. Currently, nano-drug delivery carriers mainly included liposomes, polymers, and inorganic materials. In this paper, we reveal current researches in nano-drug delivery system in bladder cancer intravesical chemotherapy by describing the applications and defects of liposomes, polymers and inorganic material nanocarriers, and provide a basis for the improvement of intravesical chemotherapy drugs in bladder cancer.

Near-Infrared Light-Triggered Thermosensitive Liposomes Modified with Membrane Peptides for the Local Chemo/Photothermal Therapy of Melanoma

Purpose

A near-infrared (NIR)-triggered trans-activating transcriptional activator (TAT)-based targeted drug delivery system for the combined chemo/photothermal therapy of melanoma, namely, TAT-TSL-TMZ (temozolomide)/IR820, was developed for the first time.

Methods

TAT-TSL-TMZ/IR820 liposomes were synthesized via thin-film dispersion and sonication. IR820 and TMZ were encased in the inner layer and lipid bilayer of the liposomes, respectively.

Results

Dynamic light scattering results showed that the liposomes had an average hydrodynamic size of 166.9 nm and a zeta potential of -2.55 mV. The encapsulation rates of TMZ and IR820 were 35.4% and 28.6%, respectively. The heating curve obtained under near-infrared (NIR) laser irradiation showed that TAT-TSL-TMZ/IR820 liposomes had good photothermal conversion efficiency. The in vitro drug release curve revealed that NIR laser irradiation could accelerate drug release from TAT-TSL-TMZ/IR820 liposomes. The results of inverted fluorescence microscopy and flow cytometry proved that the uptake of TAT-TSL-TMZ/IR820 liposomes by human melanoma cells (MV3 cells) was concentration-dependent and that the liposomes modified with membrane peptides were more likely to be ingested by cells than unmodified liposomes. Confocal laser scanning microscopy indicated that TAT-TSL-TMZ/IR820 liposomes entered MV3 cells via endocytosis and was stored in lysosomes. In addition, TAT-TSL-TMZ/IR820 liposomes exposed to NIR laser showed 89.73% reduction in cell viability.

Conclusion

This study investigated the photothermal conversion, cell uptake, colocation and chemo/photothermal effect of TAT-TSL-TMZ/IR820 liposomes.

The Urothelium: Life in a Liquid Environment

The urothelium, which lines the renal pelvis, ureters, urinary bladder, and proximal urethra, forms a high-resistance but adaptable barrier that surveils its mechanochemical environment and communicates changes to underlying tissues including afferent nerve fibers and the smooth muscle. The goal of this review is to summarize new insights into urothelial biology and function that have occurred in the past decade. After familiarizing the reader with key aspects of urothelial histology, we describe new insights into urothelial development and regeneration. This is followed by an extended discussion of urothelial barrier function, including information about the roles of the glycocalyx, ion and water transport, tight junctions, and the cellular and tissue shape changes and other adaptations that accompany expansion and contraction of the lower urinary tract. We also explore evidence that the urothelium can alter the water and solute composition of urine during normal physiology and in response to overdistension. We complete the review by providing an overview of our current knowledge about the urothelial environment, discussing the sensor and transducer functions of the urothelium, exploring the role of circadian rhythms in urothelial gene expression, and describing novel research tools that are likely to further advance our understanding of urothelial biology.

Enhanced Efficacy of PEGylated Liposomal Cisplatin: In Vitro and In Vivo Evaluation

This study aims to evaluate the potency of cisplatin (Cispt)-loaded liposome (LCispt) and PEGylated liposome (PLCispt) as therapeutic nanoformulations in the treatment of bladder cancer (BC). Cispt was loaded into liposomes using reverse-phase evaporation method, and the formulations were characterized using dynamic light scattering, scanning electron microscopy, dialysis membrane, and Fourier-transform infrared spectroscopy (FTIR) methods. The results showed that the particles were formed in spherical monodispersed shapes with a nanoscale size (221–274 nm) and controlled drug release profile. The cytotoxicity effects of LCispt and PLCispt were assessed in an in vitro environment, and the results demonstrated that PLCispt caused a 2.4- and 1.9-fold increase in the cytotoxicity effects of Cispt after 24 and 48 h, respectively. The therapeutic and toxicity effects of the formulations were also assessed on BC-bearing rats. The results showed that PLCispt caused a 4.8-fold increase in the drug efficacy (tumor volume of 11 ± 0.5 and 2.3 ± 0.1 mm³ in Cispt and PLCispt receiver rats, respectively) and a 3.3-fold decrease in the toxicity effects of the drug (bodyweight gains of 3% and 10% in Cispt and PLCispt receiver rats, respectively). The results of toxicity were also confirmed by histopathological studies. Overall, this study suggests that the PEGylation of LCispt is a promising approach to achieve a nanoformulation with enhanced anticancer effects and reduced toxicity compared to Cispt for the treatment of BC.

Rebamipide-loaded chitosan nanoparticles accelerate prostatic wound healing by inhibiting M1 macrophage-mediated inflammation via the NF-κB signaling pathway

A large proportion of benign prostatic hyperplasia (BPH) patients suffer from lower urinary tract symptoms after surgery due to the presence of prostatic urothelium wounds. Rebamipide (RBM) exerts wound healing promotion and anti-inflammatory effects on various tissues, including the urothelium. However, intravesical administration of RBM is hindered due to its low solubility and resulting unsustainable drug concentrations in the bladder. In this study, RBM-loaded chitosan nanoparticles (RBM/CTS NPs) were prepared using the ionic cross-linking method. Physicochemical characteristics and the wound healing promotion effect, as well as in vitro influence on macrophages were evaluated. The results show that RBM/CTS NPs are spherical with uniform size distribution, while slower and sustained in vitro release of RBM is presented. In vivo, faster wound healing and improved re-epithelialization progress were observed after treatment with RBM/CTS NPs in a model of thulium laser resection of the prostate (TmLRP). The degree of local inflammatory response decreased, as confirmed by decreasing numbers of pro-inflammatory M1 phenotype macrophages and levels of IL-1β, IL-6, IL-12 and TNF-α in the urine of canines. We also found that RBM/CTS NPs suppress macrophage M1 polarization induced by lipopolysaccharide and interferon-γ and inhibit the activation of the NF-κB signaling pathway. Therefore, as a novel therapeutic strategy, intravesical administration of RBM/CTS NPs can effectively avoid drug intolerance and drug wastage, accelerating the postoperative wound repairing of the prostatic urethra by suppressing macrophage M1 phenotype polarization.

Optimizing pharmacokinetics of intravesical chemotherapy for bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) remains one of the most common malignancies and is associated with considerable treatment costs. Patients with intermediate-risk or high-risk disease can be treated with intravesical BCG, but many of these patients will experience tumour recurrence, despite adequate treatment. Standard of care in these patients is radical cystectomy with urinary diversion, but this approach is associated with considerable morbidity and lifestyle modification. As an alternative, perioperative intravesical chemotherapy is recommended for low-risk papillary NMIBC, and induction intravesical chemotherapy is an option for patients with intermediate-risk NMIBC and BCG-unresponsive NMIBC. However, poor pharmaceutical absorption and drug washout during normal voiding can limit sustained drug concentrations in the urothelium, which reduces efficacy, and small-molecule chemotherapeutic agents can be absorbed through the urothelium into the bloodstream, leading to systemic adverse effects. Several novel drug delivery methods - including hyperthermia, mechanical sustained released devices and nanoparticle drug conjugation - have been developed to overcome these limitations. These novel methods have the potential to be combined with established chemotherapeutic agents to change the paradigm of NMIBC treatment.

Intravesical delivery of rapamycin via folate-modified liposomes dispersed in thermo-reversible hydrogel

Purpose

To develop an intravesical instillation system for the treatment of bladder cancer, rapamycin (Rap) was encapsulated into liposomes and then homogeneously dispersed throughout a poloxamer 407 (P407)-based hydrogel.

Methods

Rap-loaded conventional liposomes (R-CL) and folate-modified liposomes (R-FL) were prepared using a film hydration method and pre-loading technique, and characterized by particle size, drug entrapment efficiency, and drug loading. The cellular uptake behavior in folate receptor-expressing bladder cancer cells was observed by flow cytometry and confocal laser scanning microscopy using a fluorescent probe. In vitro cytotoxic effects were evaluated using MTT assay, colony forming assay, and Western blot. For in vivo intravesical instillation, Rap-loaded liposomes were dispersed in P407-gel, generating R-CL/P407 and R-FL/P407. Gel-forming capacities and drug release were evaluated. Using the MBT2/Luc orthotopic bladder cancer mouse model, in vivo antitumor efficacy was evaluated according to regions of interest (ROI) measurement.

Results

R-CL and R-FL were successfully prepared, at approximately <160 nm, 42% entrapment efficiency, and 57 μg/mg drug loading. FL cellular uptake was enhanced over 2-fold than that of CL; folate receptor-mediated endocytosis was confirmed using a competitive assay with folic acid pretreatment. In vitro cytotoxic effects increased dose-dependently. Rap-loaded liposomes inhibited mTOR signaling and induced autophagy in urothelial carcinoma cells. With gelation time of <30 seconds and gel duration of >12 hrs, both R-CL/P407 and R-FL/P407 preparations transformed into gel immediately after instillation into the mouse bladder. Drug release from the liposomal gel was erosion controlled. In orthotopic bladder cancer mouse model, statistically significant differences in ROI values were found between R-CL/P407 and R-FL/P407 groups at day 11 (P=0.0273) and day 14 (P=0.0088), indicating the highest tumor growth inhibition by R-FL/P407.

Conclusion

Intravesical instillation of R-FL/P407 might represent a good candidate for bladder cancer treatment, owing to its enhanced retention and FR-targeting.

Clinical validation of a novel thermophysical bladder model designed to improve the accuracy of hyperthermia treatment planning in the pelvic region

PURPOSE

Hyperthermia treatment planning for deep locoregional hyperthermia treatment may assist in phase and amplitude steering to optimize the temperature distribution. This study aims to incorporate a physically correct description of bladder properties in treatment planning, notably the presence of convection and absence of perfusion within the bladder lumen, and to assess accuracy and clinical implications for non muscle invasive bladder cancer patients treated with locoregional hyperthermia.

METHODS

We implemented a convective thermophysical fluid model based on the Boussinesq approximation to the Navier-Stokes equations using the (finite element) OpenFOAM toolkit. A clinician delineated the bladder on CT scans obtained from 14 bladder cancer patients. We performed (1) conventional treatment planning with a perfused muscle-like solid bladder, (2) with bladder content properties without and (3) with flow dynamics. Finally, we compared temperature distributions predicted by the three models with temperature measurements obtained during treatment.

RESULTS

Much higher and more uniform bladder temperatures are predicted with physically accurate fluid modeling compared to previously employed muscle-like models. The differences reflect the homogenizing effect of convection, and the absence of perfusion. Median steady state temperatures simulated with the novel convective model (3) deviated on average -0.6 °C (-12%) from values measured during treatment, compared to -3.7 °C (-71%) and +1.5 °C (+29%) deviation for the muscle-like (1) and static (2) models, respectively. The Grashof number was 3.2 ± 1.5 × 10⁵ (mean ± SD).

CONCLUSIONS

Incorporating fluid modeling in hyperthermia treatment planning yields significantly improved predictions of the temperature distribution in the bladder lumen during hyperthermia treatment.

Nano-BCG: A Promising Delivery System for Treatment of Human Bladder Cancer

Mycobacterium bovis bacillus Calmette–Guerin (BCG) remains at the forefront of immunotherapy for treating bladder cancer patients. However, the incidence of recurrence and progression to invasive cancer is commonly observed. There are no established effective intravesical therapies available for patients, whose tumors recur following BCG treatment, representing an important unmet clinical need. In addition, there are very limited options for patients who do not respond to or tolerate chemotherapy due to toxicities, resulting in poor overall treatment outcomes. Within this context, nanotechnology is an emergent and promising tool for: (1) controlling drug release for extended time frames, (2) combination therapies due to the ability to encapsulate multiple drugs simultaneously, (3) reducing systemic side effects, (4) increasing bioavailability, (5) and increasing the viability of various routes of administration. Moreover, bladder cancer is often characterized by high mutation rates and over expression of tumor antigens on the tumor cell surface. Therapeutic targeting of these biomolecules may be improved by nanotechnology strategies. In this mini-review, we discuss how nanotechnology can help overcome current obstacles in bladder cancer treatment, and how nanotechnology can facilitate combination chemotherapeutic and BCG immunotherapies for the treatment of non-muscle invasive urothelial bladder cancer.