Versatility of Particulate Carriers: Development of Pharmacodynamically Optimized Drug-Loaded Microparticles for Treatment of Peritoneal Cancer

Targeted Radium Alpha Therapy in the Era of Nanomedicine: In Vivo Results

Targeted alpha-particle therapy using radionuclides with alpha emission is a rapidly developing area in modern cancer treatment. To selectively deliver alpha-emitting isotopes to tumors, targeting vectors, including monoclonal antibodies, peptides, small molecule inhibitors, or other biomolecules, are attached to them, which ensures specific binding to tumor-related antigens and cell surface receptors. Although earlier studies have already demonstrated the anti-tumor potential of alpha-emitting radium (Ra) isotopes-Radium-223 and Radium-224 (223/224Ra)-in the treatment of skeletal metastases, their inability to complex with target-specific moieties hindered application beyond bone targeting. To exploit the therapeutic gains of Ra across a wider spectrum of cancers, nanoparticles have recently been embraced as carriers to ensure the linkage of 223/224Ra to target-affine vectors. Exemplified by prior findings, Ra was successfully bound to several nano/microparticles, including lanthanum phosphate, nanozeolites, barium sulfate, hydroxyapatite, calcium carbonate, gypsum, celestine, or liposomes. Despite the lengthened tumor retention and the related improvement in the radiotherapeutic effect of 223/224Ra coupled to nanoparticles, the in vivo assessment of the radiolabeled nanoprobes is a prerequisite prior to clinical usage. For this purpose, experimental xenotransplant models of different cancers provide a well-suited scenario. Herein, we summarize the latest achievements with 223/224Ra-doped nanoparticles and related advances in targeted alpha radiotherapy.

Novel Drug Delivery Systems as an Emerging Platform for Stomach Cancer Therapy

Cancer has long been regarded as one of the world's most fatal diseases, claiming the lives of countless individuals each year. Stomach cancer is a prevalent cancer that has recently reached a high number of fatalities. It continues to be one of the most fatal cancer forms, requiring immediate attention due to its low overall survival rate. Early detection and appropriate therapy are, perhaps, of the most difficult challenges in the fight against stomach cancer. We focused on positive tactics for stomach cancer therapy in this paper, and we went over the most current advancements and progressions of nanotechnology-based systems in modern drug delivery and therapies in great detail. Recent therapeutic tactics used in nanotechnology-based delivery of drugs aim to improve cellular absorption, pharmacokinetics, and anticancer drug efficacy, allowing for more precise targeting of specific agents for effective stomach cancer treatment. The current review also provides information on ongoing research aimed at improving the curative effectiveness of existing anti-stomach cancer medicines. All these crucial matters discussed under one overarching title will be extremely useful to readers who are working on developing multi-functional nano-constructs for improved diagnosis and treatment of stomach cancer.

Pharmacokinetics, tissue distribution and peritoneal retention of Ag2S quantum dots following intraperitoneal administration to mice

OBJECTIVES

To investigate the pharmacokinetics, biodistribution and peritoneal retention of Ag2S quantum dots (Qds) after intraperitoneal (IP) injection into mice and to compare the results with those reported for the intravenous (IV) injection of these particles.

METHODS

Ag2S Qds was prepared by a simple one-step co-precipitation method and was injected intraperitoneally into mice. Six animals were sacrificed at predetermined time points, and blood, peritoneal content and tissue samples were collected. Ag concentration that represents the concentration of Qds was analysed by atomic absorption spectrophotometry.

KEY FINDINGS

Detectability of Qds in the peritoneal sample up to 2 h indicated that, compared with small drug molecules, the absorption of Ag2S Qds from the peritoneal cavity occurred at a slower rate. The AUC tissue/AUC blood ratio in the liver and intestine after IP injection (0.55 and 0.98, respectively) was considerably lower than those for the bolus injection (217 and 94, respectively), while this ratio in the spleen and lungs was markedly higher than the IV route.

CONCLUSIONS

Overall, the obtained results suggest that IP injection of Ag2S Qds could be more effective for drug delivery to/imaging of the spleen and lungs, whereas the IV injection for the drug delivery to/imaging of the liver and intestine.

Enhancing ovarian cancer conventional chemotherapy through the combination with cannabidiol loaded microparticles

In this work, we evaluated, for the first time, the antitumor effect of cannabidiol (CBD) as monotherapy and in combination with conventional chemotherapeutics in ovarian cancer and developed PLGA-microparticles as CBD carriers to optimize its anticancer activity. Spherical microparticles, with a mean particle size around 25 µm and high entrapment efficiency were obtained. Microparticles elaborated with a CBD:polymer ratio of 10:100 were selected due to the most suitable release profile with a zero-order CBD release (14.13 ± 0.17 μg/day/10 mg Mps) for 40 days. The single administration of this formulation showed an in vitro extended antitumor activity for at least 10 days and an in ovo antitumor efficacy comparable to that of CBD in solution after daily topical administration (≈1.5-fold reduction in tumor growth vs control). The use of CBD in combination with paclitaxel (PTX) was really effective. The best treatment schedule was the pre + co-administration of CBD (10 µM) with PTX. Using this protocol, the single administration of microparticles was even more effective than the daily administration of CBD in solution, achieving a ≈10- and 8- fold reduction in PTX IC₅₀ respectively. This protocol was also effective in ovo. While PTX conducted to a 1.5-fold tumor growth inhibition, its combination with both CBD in solution (daily administered) and 10-Mps (single administration) showed a 2-fold decrease. These results show the promising potential of CBD-Mps administered in combination with PTX for ovarian cancer treatment, since it would allow to reduce the administered dose of this antineoplastic drug maintaining the same efficacy and, as a consequence, reducing PTX adverse effects.

Impregnation of Curcumin into a Biodegradable (Poly-lactic-co-glycolic acid, PLGA) Support, to Transfer Its Well Known In Vitro Effect to an In Vivo Prostate Cancer Model

Prostate cancer (PCa) is one of the most common cancers in older men and is associated with high mortality. Despite advances in screening for early detection of PCa, a large proportion of patients continue to be diagnosed with metastatic disease, with ~20% of men showing a high tumor grade and stage. Medicinal plant extracts have a great potential to prevent/treat PCa, as well as to reduce its incidence/prevalence and improve survival rates. One of the most promising extracts is curcumin, which is a major, nontoxic, bioactive compound of Curcuma longa. Curcumin has strong antitumor activity in vitro. However, its potential beneficial in vivo affects are limited by its low intestinal absorption and rapid metabolism. In this study, curcumin was impregnated into a biodegradable poly(lactic-co-glycolic) acid (PLGA) support and characterized by FTIR and DSC, and its release by UV spectrophotometry. PLGA-curcumin was tested in different subcutaneous PCa xenograft models (PC3, 22rv1, and DU145 PCa cell-lines), and its effects evaluated by tumor progression an immuno-histochemical analysis (Trichromic, Ki67 and TUNEL stainings), were compared with those of a commercial curcumin preparation. Our results indicate that curcumin-impregnated PLGA is significantly more active (~2-fold increase) with respect to oral curcumin, which supports its use for subcutaneous administration.

Target Site Delivery and Residence of Nanomedicines: Application of Quantitative Systems Pharmacology

Quantitative systems pharmacology (QSP), an emerging field that entails using modeling and computation to interpret, interrogate, and integrate drug effects spanning from the molecule to the whole organism to forecast treatment outcomes, is expected to enhance the efficiency of drug development. Since late 2017, the U.S. Food and Drug Administration has advocated the use of an analogous approach of model-informed drug development. This review focuses on issues pertaining to nanosized medicines (NP) and the potential utility of QSP to determine NP delivery and residence at extracellular or intracellular targets in vivo. The kinetic processes governing NP disposition and transport, interactions with biologic matrix components, binding and internalization in cells, and intracellular trafficking are determined, sometimes jointly, by NP properties (e.g., dimension, materials, surface charge and modifications, shape, and geometry) and target tissue properties (e.g., perfusion status, vessel pore size and wall thickness, vessel and cell density, composition of extracellular matrix, and void volume fraction). These various determinants, together with the heterogeneous tissue structures and microenvironment factors in solid tumors, lead to environment-, spatial-, and time-dependent changes in NP concentrations that are difficult to predict. Adding to the complexity is the recent discovery that NP surface-coating protein corona, whose composition depends on NP properties and which undergoes continuous evolution with time and local protein environments, is yet another unpredictable variable. Examples are provided to demonstrate the potential utility of QSP-based multiscale modeling to capture the physicochemical and biologic processes in equations to enable computational studies of the key kinetic processes in cancer treatments.

Systemic Bioequivalence Is Unlikely to Equal Target Site Bioequivalence for Nanotechnology Oncologic Products

Approval of generic drugs by the US Food and Drug Administration (FDA) requires the product to be pharmaceutically equivalent to the reference listed drug (RLD) and demonstrate bioequivalence (BE) in effectiveness when administered to patients under the conditions in the RLD product labeling. Effectiveness is determined by drug exposure at the target sites. However, since such measurement is usually unavailable, systemic exposure is assumed to equal target site exposure and systemic BE to equal target site BE. This assumption, while it often applies to small molecule drug products that are readily dissolved in biological fluids and systemically absorbed, is unlikely to apply to nanotechnology products (NP) that exist as heterogeneous systems and are subjected to dimension- and material-dependent changes. This commentary provides an overview of the intersecting and spatial-dependent processes and variables governing the delivery and residence of oncologic NP in solid tumors. In order to provide a quantitative perspective of the collective effects of these processes, we used quantitative systems pharmacology (QSP) multi-scale modeling to capture the physicochemical and biological events on several scales (whole-body, organ/suborgan, cell/subcellular, spatial locations, time). QSP is an emerging field that entails using modeling and computation to facilitate drug development; an analogous approach (i.e., model-informed drug development) is advocated by to FDA. The QSP model-based simulations illustrated that small changes in NP attributes (e.g., size variations during manufacturing, interactions with proteins in biological milieu) could lead to disproportionately large differences in target site exposure, rending systemic BE unlikely to equal target site BE.

Therapeutic Effect of α-Emitting 224Ra-Labeled Calcium Carbonate Microparticles in Mice with Intraperitoneal Ovarian Cancer

BACKGROUND: Ovarian cancer patients with chemotherapy-resistant residual microscopic disease in the peritoneal cavity have a considerable need for new treatment options. Alpha-emitting radionuclides injected intraperitoneally may be an attractive therapeutic option in this situation as they are highly cytotoxic, while their short range in tissues can spare surrounding radiosensitive organs in the abdomen. Herein we evaluate the therapeutic efficacy of a novel α-emitting compound specifically designed for intracavitary radiation therapy. METHODS: The α-emitter ²²⁴Ra was absorbed on calcium carbonate microparticles. Immunodeficient, athymic nude mice with human ovarian cancer cells growing intraperitoneally were treated with different activity levels of ²²⁴Ra-microparticles. Tumor growth, survival, and tolerance of the treatment were assessed. Two tumor models based on the cell lines, ES-2 and SKOV3-luc, with different growth patterns were studied. RESULTS: In both models, intraperitoneal treatment with ²²⁴Ra-microparticles gave significant antitumor effect with either considerably reduced tumor volume or a survival benefit. An advantageous discovery was that only a few kilobecquerels per mouse were needed to yield therapeutic effects. The treatment was well tolerated up to a dose of 1000 kBq/kg with no signs of acute or subacute toxicity observed. CONCLUSIONS: Intraperitoneal α-therapy with ²²⁴Ra-microparticles demonstrated a significant potential for treatment of peritoneal micrometastases in ovarian carcinoma.

Microniosomes for concurrent doxorubicin and iron oxide nanoparticles loading; preparation, characterization and cytotoxicity studies

The current work deals with developing a suitable drug delivery system of doxorubicin (DOX) for intraperitoneal chemotherapy using niosomes through formulating non-ionic surfactants consisting of Brij™ 52, span™ 60 and Solulan™ C24. Entrapping the magnetite nanoparticles in the hydrophilic parts of niosomes was accompanied with high-efficient DOX loading by the current novel remote-loading method. Cytotoxicity of the prepared formulations was evaluated in vitro against A549 and PC-12 cell lines using the colorimetric WST-1 assay test. The obtained results revealed that, the cytotoxicity of DOX increased up to 22% especially on A549 cells by the current delivery system.

Nanomedicine-based intraperitoneal therapy for the treatment of peritoneal carcinomatosis - Mission possible?

Intraperitoneal (IP) drug delivery represents an attractive strategy for the local treatment of peritoneal carcinomatosis (PC). Over the past decade, a lot of effort has been put both in the academia and clinic in developing IP therapeutic approaches that maximize local efficacy while limiting systemic side effects. Also nanomedicines are under investigation for the treatment of tumors confined to the peritoneal cavity, due to their potential to increase the peritoneal retention and to target drugs to the tumor sites as compared to free drugs. Despite the progress reported by multiple clinical studies, there are no FDA approved drugs or formulations for specific use in the IP cavity yet. This review discusses the current clinical management of PC, as well as recent advances in nanomedicine-based IP delivery. We address important challenges to be overcome towards designing optimal nanocarriers for IP therapy in vivo.

Pharmacokinetic problems in peritoneal drug administration: an update after 20 years

Intraperitoneal chemotherapy has demonstrated significant pharmacologic and clinical advantage over traditional intravenous administration for cancers that are restricted to the peritoneal cavity. The combination of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard technique used to fight ovarian and gastrointestinal cancers in many centers. However, challenges remain for HIPEC to contact the entire peritoneal surface, penetrate the tumor tissue, and transport to the lymphatics and other metastatic sites. New innovations in delivery technique, such as heated aerosol, and in delivery molecules, such as microparticles, nanoparticles, nanogels, and tumor-penetrating peptides are being tested in animal models and will likely soon be in human trials. Improvements in overall care, such as the recent clinical trial of an oral agent for maintenance therapy in ovarian carcinoma, will continue in this field for the next 20 years.

Intraperitoneal chemotherapy of ovarian cancer by hydrogel depot of paclitaxel nanocrystals

Intraperitoneal (IP) chemotherapy is a promising post-surgical therapy of ovarian cancer, but the full potential is yet to be realized. To facilitate IP chemotherapy of ovarian cancer, we developed an in-situ crosslinkable hydrogel depot containing paclitaxel (PTX) nanocrystals (PNC). PNC suppressed SKOV3 cell proliferation more efficiently than microparticulate PTX precipitates (PPT), and the gel containing PNC (PNC-gel) showed a lower maximum tolerated dose than PPT-containing gel (PPT-gel) in mice, indicating greater dissolution and cellular uptake of PNC than PPT. A single IP administration of PNC-gel extended the survival of tumor-bearing mice significantly better than Taxol, but PPT-gel did not. These results support the advantage of PNC over PPT and demonstrate the promise of a gel depot as an IP drug delivery system.

Delivery of cancer therapeutics to extracellular and intracellular targets: Determinants, barriers, challenges and opportunities

Advances in molecular medicine have led to identification of worthy cellular and molecular targets located in extracellular and intracellular compartments. Effectiveness of cancer therapeutics is limited in part by inadequate delivery and transport in tumor interstitium. Parts I and II of this report give an overview on the kinetic processes in delivering therapeutics to their intended targets, the transport barriers in tumor microenvironment and extracellular matrix (TME/ECM), and the experimental approaches to overcome such barriers. Part III discusses new concepts and findings concerning nanoparticle-biocorona complex, including the effects of TME/ECM. Part IV outlines the challenges in animal-to-human translation of cancer nanotherapeutics. Part V provides an overview of the background, current status, and the roles of TME/ECM in immune checkpoint inhibition therapy, the newest cancer treatment modality. Part VI outlines the development and use of multiscale computational modeling to capture the unavoidable tumor heterogeneities, the multiple nonlinear kinetic processes including interstitial and transvascular transport and interactions between cancer therapeutics and TME/ECM, in order to predict the in vivo tumor spatiokinetics of a therapeutic based on experimental in vitro biointerfacial interaction data. Part VII provides perspectives on translational research using quantitative systems pharmacology approaches.