Nanotechnology and cancer: improving real-time monitoring and staging of bladder cancer with multimodal mesoporous silica nanoparticles

Clinical insights into nanomedicine and biosafety: advanced therapeutic approaches for common urological cancers

Urological cancers including those of the prostate, bladder, and kidney, are prevalent and often lethal malignancies besides other less common ones like testicular and penile cancers. Current treatments have major limitations like side effects, recurrence, resistance, high costs, and poor quality of life. Nanotechnology offers promising solutions through enhanced diagnostic accuracy, targeted drug delivery, controlled release, and multimodal imaging. This review reflects clinical challenges and nanomedical advances across major urological cancers. In prostate cancer, nanoparticles improve delineation and radiosensitization in radiation therapy, enable fluorescent guidance in surgery, and enhance chemotherapy penetration in metastatic disease. Nanoparticles also overcome bladder permeability barriers to increase the residence time of intravesical therapy and chemotherapy agents. In renal cancer, nanocarriers potentiate tyrosine kinase inhibitors and immunotherapy while gene vectors and zinc oxide nanoparticles demonstrate antiproliferative effects. Across modalities, urological applications of nanomedicine include polymeric, liposomal, and metal nanoparticles for targeted therapy, prodrug delivery, photodynamic therapy, and thermal ablation. Biosafety assessments reveal favorable profiles but clinical translation remains limited, necessitating further trials. In conclusion, nanotechnology holds significant potential for earlier detection, precise intervention, and tailored treatment of urological malignancies, warranting expanded research to transform patient outcomes.

Non-Invasive Imaging Modalities in Intravesical Murine Models of Bladder Cancer

Bladder cancer (BCa) is the sixth most prevalent cancer in men and seventeenth most prevalent cancer in women worldwide. Current treatment paradigms have limited therapeutic impact, suggesting an urgent need for the investigation of novel therapies. To best emulate the progression of human BCa, a pre-clinical intravesical murine model is required in conjunction with existing non-invasive imaging modalities to detect and evaluate cancer progression. Non-invasive imaging modalities reduce the number of required experimental models while allowing for longitudinal studies of novel therapies to investigate long-term efficacy. In this review, we discuss the individual and multi-modal use of non-invasive imaging modalities; bioluminescence imaging (BLI), micro-ultrasound imaging (MUI), magnetic resonance imaging (MRI), and positron emission tomography (PET) in BCa evaluation. We also provide an update on the potential and the future directions of imaging modalities in relation to intravesical murine models of BCa.

Nanoparticle-Based Techniques for Bladder Cancer Imaging: A Review

Bladder cancer is very common in humans and is often characterized by recurrences, compromising the patient's quality of life with a substantial social and economic impact. Both the diagnosis and treatment of bladder cancer are problematic due to the exceptionally impermeable barrier formed by the urothelium lining the bladder; this hinders the penetration of molecules via intravesical instillation while making it difficult to precisely label the tumor tissue for surgical resection or pharmacologic treatment. Nanotechnology has been envisaged as an opportunity to improve both the diagnostic and therapeutic approaches for bladder cancer since the nanoconstructs can cross the urothelial barrier and may be functionalized for active targeting, loaded with therapeutic agents, and visualized by different imaging techniques. In this article, we offer a selection of recent experimental applications of nanoparticle-based imaging techniques, with the aim of providing an easy and rapid technical guide for the development of nanoconstructs to specifically detect bladder cancer cells. Most of these applications are based on the well-established fluorescence imaging and magnetic resonance imaging currently used in the medical field and gave positive results on bladder cancer models in vivo, thus opening promising perspectives for the translation of preclinical results to the clinical practice.

Nanomedicine for Combination Urologic Cancer Immunotherapy

Urologic cancers, particularly kidney, bladder, and prostate cancer, have a growing incidence and account for about a million annual deaths worldwide. Treatments, including surgery, chemotherapy, radiotherapy, hormone therapy, and immunotherapy are the main therapeutic options in urologic cancers. Immunotherapy is now a clinical reality with marked success in solid tumors. Immunological checkpoint blockade, non-specific activation of the immune system, adoptive cell therapy, and tumor vaccine are the main modalities of immunotherapy. Immunotherapy has long been used to treat urologic cancers; however, dose-limiting toxicities and low response rates remain major challenges in the clinic. Herein, nanomaterial-based platforms are utilized as the "savior". The combination of nanotechnology with immunotherapy can achieve precision medicine, enhance efficacy, and reduce toxicities. In this review, we highlight the principles of cancer immunotherapy in urology. Meanwhile, we summarize the nano-immune technology and platforms currently used for urologic cancer treatment. The ultimate goal is to help in the rational design of strategies for nanomedicine-based immunotherapy in urologic cancer.

Designing Intelligent Nanomaterials to Achieve Highly Sensitive Diagnoses and Multimodality Therapy of Bladder Cancer

Bladder cancer (BC) is among the most common malignant tumors of the genitourinary system worldwide. In recent years, the rate of BC incidence has increased, and the recurrence rate is high, resulting in poor quality of life for patients. Therefore, how to develop an effective method to achieve synchronous precise diagnoses and BC therapies is a difficult problem to solve clinically. Previous reports usually focus on the role of nanomaterials as drug delivery carriers, while a summary of the functional design and application of nanomaterials is lacking. Summarizing the application of functional nanomaterials in high-sensitivity diagnosis and multimodality therapy of BC is urgently needed. This review summarizes the application of nanotechnology in BC diagnosis, including the application of nanotechnology in the sensoring of BC biomarkers and their role in monitoring BC. In addition, conventional and combination therapies strategy in potential BC therapy are analyzed. Moreover, different kinds of nanomaterials in BC multimodal therapy according to pathological features of BC are also outlined. The goal of this review is to present an overview of the application of nanomaterials in the theranostics of BC to provide guidance for the application of functional nanomaterials to precisely diagnose and treat BC.

Current advances in the application of nanomedicine in bladder cancer

Bladder cancer is the most common malignant tumor of the urinary system, however there are several shortcomings in current diagnostic and therapeutic measures. In terms of diagnosis, the diagnostic tools currently available are not sufficiently sensitive and specific, and imaging is poor, leading to misdiagnosis and missed diagnoses, which can delay treatment. In terms of treatment, current treatment options include surgery, chemotherapy, immunotherapy, gene therapy, and other emerging treatments, as well as combination therapies. However, the main reasons for poor efficacy and side effects during treatment are the lack of specificity and targeting, improper dose control of drugs and photosensitizers, damage to normal cells while attacking cancer cells, and difficulty in delivering siRNA to cancer cells. Nanomedicine is an emerging approach. Among the many nanotechnologies applied in the medical field, nanocarrier-assisted drug delivery systems have attracted extensive research interest due to their great translational value. Well-designed nanoparticles can deliver agents or drugs to specific cell types within target organs through active targeting or passive targeting (enhanced permeability and retention), which allows for imaging, diagnosis, as well as treatment of cancer. This paper reviews advances in the application of various nanocarriers and their advantages and drawbacks, with a focus on their use in the diagnosis and treatment of bladder cancer.

Current applications of nanomaterials in urinary system tumors

The development of nanotechnology and nanomaterials has provided insights into the treatment of urinary system tumors. Nanoparticles can be used as sensitizers or carriers to transport drugs. Some nanoparticles have intrinsic therapeutic effects on tumor cells. Poor patient prognosis and highly drug-resistant malignant urinary tumors are worrisome to clinicians. The application of nanomaterials and the associated technology against urinary system tumors offers the possibility of improving treatment. At present, many achievements have been made in the application of nanomaterials against urinary system tumors. This review summarizes the latest research on nanomaterials in the diagnosis and treatment of urinary system tumors and provides novel ideas for future research on nanotechnologies in this field.

Mesoporous Silica Nanoparticles Enhance the Anticancer Efficacy of Platinum(IV)-Phenolate Conjugates in Breast Cancer Cell Lines

The main reasons for the limited clinical efficacy of the platinum(II)-based agent cisplatin include drug resistance and significant side effects. Due to their better stability, as well as the possibility to introduce biologically active ligands in their axial positions constructing multifunctional prodrugs, creating platinum(IV) complexes is a tempting strategy for addressing these limitations. Another strategy for developing chemotherapeutics with lower toxicity relies on the ability of nanoparticles to accumulate in greater quantities in tumor tissues through passive targeting. To combine the two approaches, three platinum(IV) conjugates based on a cisplatin scaffold containing in the axial positions derivatives of caffeic and ferulic acid were prepared and loaded into SBA-15 to produce the corresponding mesoporous silica nanoparticles (MSNs). The free platinum(IV) conjugates demonstrated higher or comparable activity with respect to cisplatin against different human breast cancer cell lines, while upon immobilization, superior antiproliferative activity with markedly increased cytotoxicity (more than 1000-fold lower IC50 values) compared to cisplatin was observed. Mechanistic investigations with the most potent conjugate, cisplatin-diacetyl caffeate (1), and the corresponding MSNs (SBA-15|1) in a 4T1 mouse breast cancer cell line showed that these compounds induce apoptotic cell death causing strong caspase activation. In vivo, in BALB/c mice, 1 and SBA-15|1 inhibited the tumor growth while decreasing the necrotic area and lowering the mitotic rate.

Nanomedicine for urologic cancers: diagnosis and management

Urologic cancers accounted for more than 2 million new cases and around 0.8 million deaths in 2020. Although surgery, chemotherapy, and radiotherapy, as well as castration for prostate cancer, remain the cornerstones for managing urologic neoplasms, they can result in severe adverse effects, poor patient compliance, and unsatisfactory survival rates, thus, it is essential to develop novel options that enable the early detection of these malignancies, together with providing accurate diagnoses, and more efficient treatment strategies. Nanomedicine represents an emerging approach that can deliver formulations or drugs across traditional biological barriers in the body and be directed to specific cell types within target organs via active targeting or passive targeting, thus, showing potential to improve the management of urologic cancers. In this review, we discussed the most recent updates on the application of nanomedicines in the diagnosis and treatment of urologic cancers, with focus on prostate, bladder and kidney tumors. We also presented the anti-tumor molecular mechanisms of newly designed nanomedicine for treating urologic cancers, mainly including image-guided surgery, chemotherapy, radiotherapy, gene therapy, immunotherapy, and their synergetic therapy. Current studies have demonstrated the potential advantages of nanomedicine over conventional approaches. However, most developments and new findings in this area have not been validated in clinical trials yet, and therefore, efforts shall be made to translate these research insights into clinical practices for urologic cancers.

Antitumor activity of solamargine in mouse melanoma model: relevance to clinical safety

Melanoma is the most aggressive type of skin cancer, and thus it is important to develop new drugs for its treatment. The present study aimed to examine the antitumor effects of solamargine a major alkaloid heteroside present in Solanum lycocarpum fruit. In addition solamargine was incorporated into nanoparticles (NP) of yttrium vanadate functionalized with 3-chloropropyltrimethoxysilane (YVO₄:Eu³⁺:CPTES:SM) to determine antitumor activity. The anti-melanoma assessment was performed using a syngeneic mouse melanoma model B16F10 cell line. In addition, systemic toxicity, nephrotoxic, and genotoxic parameters were assessed. Solamargine, at doses of 5 or 10 mg/kg/day administered subcutaneously to male C57BL/6 mice for 5 days, decreased tumor size and frequency of mitoses in tumor tissue, indicative of a decrease in cell proliferation. Treatments with YVO₄:Eu³⁺:CPTES:SM significantly reduced the number of mitoses in tumor tissue, associated with no change in tumor size. There were no apparent signs of systemic toxicity, nephrotoxicity, and genotoxicity initiated by treatments either with solamargine alone or plant alkaloid incorporated into NP. The animals treated with YVO₄:Eu³⁺:CPTES:SM exhibited significant increase in spleen weight accompanied by no apparent histological changes in all tissues examined. In addition, animals treated with solamargine (10 mg/kg/day) and YVO₄:Eu³⁺:CPTES:SM demonstrated significant reduction in hepatic DNA damage which was induced by tumor growth. Therefore, data suggest that solamargine may be considered a promising candidate in cancer therapy with no apparent toxic effects.

Cisplatin-cyclooxygenase inhibitor conjugates, free and immobilised in mesoporous silica SBA-15, prove highly potent against triple-negative MDA-MB-468 breast cancer cell line

For the development of anticancer drugs with higher activity and reduced toxicity, two approaches were combined: preparation of platinum(IV) complexes exhibiting higher stability compared to their platinum(II) counterparts and loading them into mesoporous silica SBA-15 with the aim to utilise the passive enhanced permeability and retention (EPR) effect of nanoparticles for accumulation in tumour tissues. Three conjugates based on a cisplatin scaffold bearing the anti-inflammatory drugs naproxen, ibuprofen or flurbiprofen in the axial positions (1, 2 and 3, respectively) were synthesised and loaded into SBA-15 to afford the mesoporous silica nanoparticles (MSNs) SBA-15|1, SBA-15|2 and SBA-15|3. Superior antiproliferative activity of both free and immobilised conjugates in a panel of four breast cancer cell lines (MDA-MB-468, HCC1937, MCF-7 and BT-474) with markedly increased cytotoxicity with respect to cisplatin was demonstrated. All compounds exhibit highest activity against the triple-negative cell line MDA-MB-468, with conjugate 1 being the most potent. However, against MCF-7 and BT-474 cell lines, the most notable improvement was found, with IC₅₀ values up to 240-fold lower than cisplatin. Flow cytometry assays clearly show that all compounds induce apoptotic cell death elevating the levels of both early and late apoptotic cells. Furthermore, autophagy as well as formation of reactive oxygen species (ROS) and nitric oxide (NO) were elevated to a similar or greater extent than with cisplatin.

Antitumor potential of cisplatin loaded into SBA-15 mesoporous silica nanoparticles against B16F1 melanoma cells: in vitro and in vivo studies

CP (cisplatin) and mesoporous silica SBA-15 (Santa Barbara amorphous 15) loaded with CP (→SBA-15|CP) were tested in vitro and in vivo against low metastatic mouse melanoma B16F1 cell line. SBA-15 only, as drug carrier, is found to be not active, while CP and SBA-15|CP revealed high cytotoxicity in lower μM range. The activity of SBA-15|CP was found similar to the activity of CP alone. Both CP and SBA-15|CP induced inhibition of cell proliferation (carboxyfluorescein succinimidyl ester - CFSE assay) along with G2/M arrest (4',6-diamidino-2-phenylindole - DAPI assay). Apoptosis (Annexin V/ propidium iodide - PI assay), through caspase activation (apostat assay) and nitric oxide (NO) production (diacetate(4-amino-5-methylamino-2',7'-difluorofluorescein-diacetat) - DAF FM assay), was identified as main mode of cell death. However, slight elevated autophagy (acridine orange - AO assay) was detected in treated B16F1 cells. CP and SBA-15|CP did not affect production of ROS (reactive oxygen species) in B16F1 cells. Both SBA-15|CP and CP induced in B16F1 G2 arrest and subsequent senescence. SBA-15|CP, but not CP, blocked the growth of melanoma in C57BL/6 mice. Moreover, hepato- and nephrotoxicity in SBA-15|CP treated animals were diminished in comparison to CP confirming multiply improved antitumor potential of immobilized CP. Outstandingly, SBA-15 boosted in vivo activity and diminished side effects of CP.

Demethylation of the NRF2 Promoter Protects Against Carcinogenesis Induced by Nano-SiO2

Nano silicon dioxide (Nano-SiO₂) has been widely used in industries such as the field of biomedical engineering. Despite the existing evidence that Nano-SiO₂ exposure could induce oxidative stress and inflammatory responses in multiple organ systems, the carcinogenicity of Nano-SiO₂ exposure has rarely been investigated. Thus in this study, two types of human bronchial epithelial cell lines (16HBE and BEAS-2B) were selected as in vitro models to investigate the carcinogenicity of Nano-SiO₂. Our results revealed that Nano-SiO₂ induces a malignant cellular transformation in human bronchial epithelial cells according to the soft agar colony formation assay. The carcinogenesis induced by Nano-SiO₂ was also confirmed in nude mice. By using immunofluorescence assay and high-performance capillary electrophoresis (HPCE), we observed a genome-wide DNA hypomethylation induced by Nano-SiO₂. Besides the reduced enzyme activity of total DNMTs upon Nano-SiO₂ treatment, altered expression of DNMTs and methyl-CpG binding proteins were observed. Besides, we found that the expression of NRF2 was activated by demethylation of CpG islands within the NRF2 promoter region and the overexpression of NRF2 could alleviate the carcinogenesis induced by Nano-SiO₂. Taken together, our results suggested that Nano-SiO₂ induces malignant cellular transformation with a global DNA hypomethylation, and the demethylation of NRF2 promoter activates the expression of NRF2, which plays an important role in protecting against the carcinogenesis induced by Nano-SiO₂.

Assessing the cytotoxic potential of glycoalkaloidic extract in nanoparticles against bladder cancer cells

OBJECTIVE

This study proposed to use the nanotechnology to deliver glycoalkaloidic extract (AE) to bladder cancer cells, evaluating their activity in 2D and 3D models and the biological mechanism of cell death.

METHODS

NPs were prepared by nanoprecipitation method using polylactic acid (PLA) and characterized considering their size, charge, particle concentration and stability. The cytotoxicity was evaluated in 2D and 3D model, and the apoptosis and cell cycle were investigated using flow cytometry.

KEY FINDINGS

NPs loading AE (NP-AE) had diameter around 125 ± 6 nm (PdI <0.1) and negative charge. The encapsulation efficiency of SM and SS was higher than 85% for both compounds. The obtained formulation showed a significant in-vitro cytotoxic effect against RT4 cells in a dose-dependent manner with IC₅₀ two fold lower than the free AE. The cytotoxic effect of NP-AE was mediated by apoptosis and cell cycle arrested in the S phase. RT4 cells cultured under 3D conditions exhibited a higher resistance to the treatments (IC₅₀ ~ three fold higher than in 2D cell culture).

CONCLUSION

The NP-AE might be a promising nanocarrier to load and deliver glycoalkaloids against bladder cancer.

Reduction of Nanoparticle Load in Cells by Mitosis but Not Exocytosis

The long-term fate of biomedically relevant nanoparticles (NPs) at the single cell level after uptake is not fully understood yet. We report that lysosomal exocytosis of NPs is not a mechanism to reduce the particle load. Biopersistent NPs such as nonporous silica and gold remain in cells for a prolonged time. The only reduction of the intracellular NP number is observed via cell division, e.g., mitosis. Additionally, NP distribution after cell division is observed to be asymmetrical, likely due to the inhomogeneous location and distribution of the NP-loaded intracellular vesicles in the mother cells. These findings are important for biomedical and hazard studies as the NP load per cell can vary significantly. Furthermore, we highlight the possibility of biopersistent NP accumulation over time within the mononuclear phagocyte system.

Tracking embryonic hematopoietic stem cells to the bone marrow: nanoparticle options to evaluate transplantation efficiency

BACKGROUND

As the prevalence of therapeutic approaches involving transplanted cells increases, so does the need to noninvasively track the cells to determine their homing patterns. Of particular interest is the fate of transplanted embryonic stem cell-derived hematopoietic progenitor cells (HPCs) used to restore the bone marrow pool following sublethal myeloablative irradiation. The early homing patterns of cell engraftment are not well understood at this time. Until now, longitudinal studies were hindered by the necessity to sacrifice several mice at various time points of study, with samples of the population of lymphoid compartments subsequently analyzed by flow cytometry or fluorescence microscopy. Thus, long-term study and serial analysis of the transplanted cells within the same animal was cumbersome, making difficult an accurate documentation of engraftment, functionality, and cell reconstitution patterns.

METHODS

Here, we devised a noninvasive, nontoxic modality for tracking early HPC homing patterns in the same mice longitudinally over a period of 9 days using mesoporous silica nanoparticles (MSNs) and magnetic resonance imaging.

RESULTS

This approach of potential translational importance helps to demonstrate efficient uptake of MSNs by the HPCs as well as retention of MSN labeling in vivo as the cells were traced through various organs, such as the spleen, bone marrow, and kidney. Altogether, early detection of the whereabouts and engraftment of transplanted stem cells may be important to the overall outcome. To accomplish this, there is a need for the development of new noninvasive tools.

CONCLUSIONS

Our data suggest that multifunctional MSNs can label viably blood-borne HPCs and may help document the distribution and homing in the host followed by successful reconstitution.

Multifunctional nanomedicine with silica: Role of silica in nanoparticles for theranostic, imaging, and drug monitoring

The idea of multifunctional nanomedicine that enters the human body to diagnose and treat disease without major surgery is a long-standing dream of nanomaterials scientists. Nanomaterials show incredible properties that are not found in bulk materials, but achieving multi-functionality on a single material remains challenging. Integrating several types of materials at the nano-scale is critical to the success of multifunctional nanomedicine device. Here, we describe the advantages of silica nanoparticles as a tool for multifunctional nano-devices. Silica nanoparticles have been intensively studied in drug delivery due to their biocompatibility, degradability, tunable morphology, and ease of modification. Moreover, silica nanoparticles can be integrated with other materials to obtain more features and achieve theranostic capabilities and multimodality for imaging applications. In this review, we will first compare the properties of silica nanoparticles with other well-known nanomaterials for bio-applications and describe typical routes to synthesize and integrate silica nanoparticles. We will then highlight theranostic and multimodal imaging application that use silica-based nanoparticles with a particular interest in real-time monitoring of therapeutic molecules. Finally, we will present the challenges and perspective on future work with silica-based nanoparticles in medicine.

Multifunctional nanoparticles for real-time evaluation of toxicity during fetal development

Increasing production of nanomaterials in industrial quantities has led to public health concerns regarding exposure, particularly among pregnant women and developing fetuses. Information regarding the barrier capacity of the placenta for various nanomaterials is limited due to challenges working with ex vivo human placentas or in vivo animal models. To facilitate real-time in vivo imaging of placental transport, we have developed a novel, multifunctional nanoparticle, based on a core of mesoporous silica nanoparticles (MSN), and functionalized for magnetic resonance imaging (MRI), ultrasound, and fluorescent microscopy. Our MSN particles were tested as a tracking method for harmful and toxic nanomaterials. In gravid mice, intravenous injections of MSN were administered in the maternal circulation in early gestation (day 9) and late gestation (day 14). MRI and ultrasound were used to track the MSN following the injections. Changes in contrast relative to control mice indicated that MSN were observed in the embryos of mice following early gestation injections, while MSN were excluded from the embryo by the placenta following late gestation injections. The timing of transplacental barrier porosity is consistent with the notion that in mice there is a progressive increasing segregation by the placenta in later gestation. In addition, built-in physico-chemical properties of our MSN may present options for the therapeutic treatment of embryonic exposure. For example, if preventive measures such as detoxification of harmful compounds are implemented, the particle size and exposure timing can be tailored to selectively distribute to the maternal side of the trophoblast or delivered to the fetus.

Advancements in optical techniques and imaging in the diagnosis and management of bladder cancer

Accurate detection and staging is critical to the appropriate management of urothelial cancer (UC). The use of advanced optical techniques during cystoscopy is becoming more widespread to prevent recurrent nonmuscle invasive bladder cancer. Standard of care for muscle-invasive UC includes the use of computed tomography and/or magnetic resonance imaging, but staging accuracy of these tests remains imperfect. Novel imaging modalities are being developed to improve current test performance. Positron emission tomography/computed tomography has a role in the initial evaluation of select patients with muscle-invasive bladder cancer and in disease recurrence in some cases. Several novel immuno-positron emission tomography tracers are currently in development to address the inadequacy of current imaging modalities for monitoring of tumor response to newer immune-based treatments. This review summaries the current standards and recent advances in optical techniques and imaging modalities in localized and metastatic UC.

Increased endocytosis of magnetic nanoparticles into cancerous urothelial cells versus normal urothelial cells

The blood-urine barrier is the tightest and most impermeable barrier in the body and as such represents a problem for intravesical drug delivery applications. Differentiation-dependent low endocytotic rate of urothelial cells has already been noted; however, the differences in endocytosis of normal and cancer urothelial cells have not been exploited yet. Here we analysed the endocytosis of rhodamine B isothiocyanate-labelled polyacrylic acid-coated cobalt ferrite nanoparticles (NPs) in biomimetic urothelial in vitro models, i.e., in highly and partially differentiated normal urothelial cells, and in cancer cells of the papillary and invasive urothelial neoplasm. We demonstrated that NPs enter papillary and invasive urothelial neoplasm cells by ruffling of the plasma membrane and engulfment of NP aggregates by macropinocytotic mechanism. Transmission electron microscopy (TEM) and spectrophotometric analyses showed that the efficacy of NPs delivery into normal urothelial cells and intercellular space is largely restricted, while it is significantly higher in cancer urothelial cells. Moreover, we showed that the quantification of fluorescent NP internalization in cells or tissues based on fluorescence detection could be misleading and overestimated without TEM analysis. Our findings contribute to the understanding of endocytosis-mediated cellular uptake of NPs in cancer urothelial cells and reveal a highly selective mechanism to distinguish cancer and normal urothelial cells.

Biocompatibility of Multi-Imaging Engineered Mesoporous Silica Nanoparticles: In Vitro and Adult and Fetal In Vivo Studies

Despite potentially serious adverse effects of engineered nanoparticles on maternal health and fetal development, little is known about their transport across the placenta. Human and animal studies are primarily limited to ex vivo approaches; the lack of a real-time, minimally invasive tool to study transplacental transport is clear. We have developed functionalized mesoporous silica nanoparticles (MSN) for use in magnetic resonance, ultrasound, and fluorescent imaging. This material is designed as a model for, or a carrier of, environmental toxicants, allowing for in vivo evaluation. To establish a baseline of biocompatibility, we present data describing MSN tolerance using in vitro and in vivo models. In cultured cells, MSN were tolerated to a dose of 125 µg/mL with minimal effect on viability and doubling time. For the 42 day duration of the study, none of the mice exhibited behaviors usually indicative of distress (lethargy, anemia, loss of appetite, etc.). In gravid mice, the body and organ weights of MSN-exposed dams were equivalent to those of control dams. Embryos exposed to MSN during early gestation were underweight by a small degree, while embryos exposed during late gestation were of a slightly larger weight. The rate of spontaneous fetal resorptions were equivalent in exposed and control mice. Maternal livers and sera were screened for a complement of cytokines/chemokines and reactive oxygen/nitrogen species (ROS/RNS). Only granulocyte-colony stimulating factor was elevated in mice exposed to MSN during late gestation, while ROS/RNS levels were elevated in mice exposed during early/mid gestation. These findings may usher future experiments investigating environmental toxicants using real-time assessment of transport across the placenta.

A Murine Orthotopic Bladder Tumor Model and Tumor Detection System

This protocol describes the generation of bladder tumors in female C57BL/6J mice using the murine bladder cancer cell line MB49, which has been modified to secrete human Prostate Specific Antigen (PSA), and the procedure for the confirmation of tumor implantation. In brief, mice are anesthetized using injectable drugs and are made to lay in the dorsal position. Urine is vacated from the bladder and 50 µL of poly-L-lysine (PLL) is slowly instilled at a rate of 10 µL/20 s using a 24 G IV catheter. It is left in the bladder for 20 min by stoppering the catheter. The catheter is removed and PLL is vacated by gentle pressure on the bladder. This is followed by instillation of the murine bladder cancer cell line (1 x 10⁵ cells/50 µL) at a rate of 10 µL/20 s. The catheter is stoppered to prevent premature evacuation. After 1 h, the mice are revived with a reversal drug, and the bladder is vacated. The slow instillation rate is important, as it reduces vesico-ureteral reflux, which can cause tumors to occur in the upper urinary tract and in the kidneys. The cell line should be well re-suspended to reduce clumping of cells, as this can lead to uneven tumor sizes after implantation. This technique induces tumors with high efficiency. Tumor growth is monitored by urinary PSA secretion. PSA marker monitoring is more reliable than ultrasound or fluorescence imaging for the detection of the presence of tumors in the bladder. Tumors in mice generally reach a maximum size that negatively impacts health by about 3 - 4 weeks if left untreated. By monitoring tumor growth, it is possible to differentiate mice that were cured from those that were not successfully implanted with tumors. With only end-point analysis, the latter may be mistakenly assumed to have been cured by therapy.

Combining vitamin B12 and cisplatin-loaded porous silica nanoparticles via coordination: a facile approach to prepare a targeted drug delivery system

In this work, a novel drug delivery system for targeted therapy is developed based on noncovalent interactions.

SBA-15 mesoporous silica particles loaded with cisplatin induce senescence in B16F10 cells

Nanoparticles obtained by loading of cisplatin into mesoporous silica SBA-15 (SBA-15|CP) change the phenotype of surviving B16F10 melanoma cells from malignant to senescent.