Dexamethasone: Insights into Pharmacological Aspects, Therapeutic Mechanisms, and Delivery Systems

Dexamethasone (DEX) has been widely used to treat a variety of diseases, including autoimmune diseases, allergies, ocular disorders, cancer, and, more recently, COVID-19. However, DEX usage is often restricted in the clinic due to its poor water solubility. When administered through a systemic route, it can elicit severe side effects, such as hypertension, peptic ulcers, hyperglycemia, and hydro-electrolytic disorders. There is currently much interest in developing efficient DEX-loaded nanoformulations that ameliorate adverse disease effects inhibiting advancements in scientific research. Various nanoparticles have been developed to selectively deliver drugs without destroying healthy cells or organs in recent years. In the present review, we have summarized some of the most attractive applications of DEX-loaded delivery systems, including liposomes, polymers, hydrogels, nanofibers, silica, calcium phosphate, and hydroxyapatite. This review provides our readers with a broad spectrum of nanomedicine approaches to deliver DEX safely.

Chitosan: A versatile bio-platform for breast cancer theranostics

Breast cancer is considered one of the utmost neoplastic diseases globally, with a high death rate of patients. Over the last decades, many approaches have been studied to early diagnose and treat it, such as chemotherapy, hormone therapy, immunotherapy, and MRI and biomarker tests; do not show the optimal efficacy. These existing approaches are accompanied by severe side effects, thus recognizing these challenges, a great effort has been done to find out the new remedies for breast cancer. Main finding: Nanotechnology opened a new horizon to the treatment of breast cancer. Many nanoparticulate platforms for the diagnosis of involved biomarkers and delivering antineoplastic drugs are under either clinical trials or just approved by the Food and Drug Administration (FDA). It is well known that natural phytochemicals are successfully useful to treat breast cancer because these natural compounds are safer, available, cheaper, and have less toxic effects. Chitosan is a biocompatible and biodegradable polymer. Further, it has outstanding features, like chemical functional groups that can easily modify our interest with an exceptional choice of promising applications. Abundant studies were directed to assess the chitosan derivative-based nanoformulation's abilities in delivering varieties of drugs. However, the role of chitosan in diagnostics and theranostics not be obligated. The present servey will discuss the application of chitosan as an anticancer drug carrier such as tamoxifen, doxorubicin, paclitaxel, docetaxel, etc. and also, its role as a theranostics (i.e. photo-responsive and thermo-responsive) moieties. The therapeutic and theranostic potential of chitosan in cancer is promising and it seems that to have a good potential to get to the clinic.

LCC-09, a Novel Salicylanilide Derivative, Exerts Anti-Inflammatory Effect in Vascular Endothelial Cells

OBJECTIVE

Endothelial cell (EC) activation facilitates leukocyte adhesion to vascular walls, which is implicated in a variety of cardiovascular diseases and is a target for prevention and treatment. Despite the development of anti-inflammatory medications, cost-effective therapies with significant anti-inflammatory effects and lower organ toxicity remain elusive. The goal of this study is to identify novel synthetic compounds that inhibit EC inflammatory response with minimal organ toxicity.

METHODS AND RESULTS

In this study, we discovered LCC-09, a salicylanilide derivative consisting of the functional fragment of magnolol, 2,4-difluorophenyl, and paeonol moiety of salicylate, as a novel anti-inflammatory compound in cultured ECs and zebrafish model. LCC-09 was shown to inhibit pro-inflammatory cytokine tumor necrosis factor-α (TNFα)-induced expression of adhesion molecules and inflammatory cytokines, leading to reduced leukocyte adhesion to ECs. Mechanistically, LCC-09 inhibits the phosphorylation of signal transducer and activator of transcription 1 (STAT1), TNFα-induced degradation of NF-κ-B Inhibitor-α (IκBα) and phosphorylation of NFκB p65, resulting in reduced NFκB transactivation activity and binding to E-selectin promoter. Additionally, LCC-09 attenuated TNFα-induced generation of reactive oxygen species in ECs. Molecular docking models suggest the binding of LCC-09 to NFκB essential modulator (NEMO) and Janus tyrosine kinase (JAK) may lead to dual inhibition of NFκB and STAT1. Furthermore, the anti-inflammatory effect of LCC-09 was validated in the lipopolysaccharides (LPS)-induced inflammation model in zebrafish. Our results demonstrated that LCC-09 significantly reduced the LPS-induced leukocyte recruitment and mortality of zebrafish embryos. Finally, LCC-09 was administered to cultured ECs and zebrafish embryos and showed minimal toxicities.

CONCLUSION

Our results support that LCC-09 inhibits EC inflammatory response but does not elicit significant toxicity.

Novel Suberoylanilide Hydroxamic Acid Analogs Inhibit Angiogenesis and Induce Apoptosis in Breast Cancer Cells

BACKGROUND

Histone deacetylases (HDACs) are the enzymes that catalyze the removal of the acetyl group from lysine residues and regulate several biological processes. Suberoylanilide hydroxamic acid (SAHA) is a notable HDAC inhibitor that exhibited remarkable anti-proliferative efficiency by alleviating gene regulation against solid and hematologic cancers.

AIM

The aim of this study was to develop new chemotherapeutic agents for breast cancer treatment, therefore, a novel series of Suberoylanilide hydroxamic acid (SAHA) analogs were investigated as anticancer agents.

METHODS

We designed and synthesized a novel series of analogs derived from SAHA by substituting alkyl, alkoxy, halo, and benzyl groups at different positions of the phenyl ring. The newly synthesized analogs were assessed for their cytotoxic potential against four human cancer cell lines in comparison with healthy cell lines, using several biological assays.

RESULTS

SAHA analogs displayed significant cytotoxic potential with IC50 values ranging from 1.6 to 19.2 µM in various tumor cell lines. Among these analogs, 2d (containing 3-chloro, 4-floro substitutions on phenyl moiety), 2h (containing 3,4-di chloro substitutions on phenyl moiety), and 2j (containing 4-chloro, 3-methyl substitutions on phenyl moiety) showed significant cytotoxic potential with IC50 values ranging from 1.6 to 1.8 µM in MCF-7 (breast carcinoma) cell line. More importantly, these analogs were found to be non-toxic towards healthy primary human hepatocytes (PHH) and mouse fibroblast cells (NIH3T3), which represent their tumor selectivity. These analogs were further analyzed for their effect on cell migration, BrdU incorporation, Annexin V-FITC and cell cycle arrest (Sub-G1 phase). Remarkably, analogs 2d, 2h, and 2j displayed significant HDAC inhibition than the parent SAHA molecule. Further studies also confirmed that these SAHA analogs are efficient in inducing apoptosis, as they regulated the expression of several proteins involved in mitochondrial or intrinsic apoptosis pathways. Findings in the Chick Chorioallantoic Membrane (CAM) assay studies revealed anti-angiogenic properties of the currently described SAHA analogs.

CONCLUSION

From anti-proliferative study results, it is clearly evident that 3,4-substitution at the SAHA phenyl ring improves the anti-proliferative activity of SAHA. Based on these findings, we presume that the synthesized novel SAHA analogs could be potential therapeutic agents in treating breast cancer.

Enriched pharmacokinetic behavior and antitumor efficacy of thymoquinone by liposomal delivery

Background: Thymoquinone (TQ) has potential anti-inflammatory, immunomodulatory and anticancer effects but its clinical use is limited by its low solubility, poor bioavailability and rapid clearance. Aim: To enhance systemic bioavailability and tumor-specific toxicity of TQ. Materials & methods: Cationic liposomal formulation of TQ (D1T) was prepared via ethanol injection method and their physicochemical properties, anticancer effects in orthotopic xenograft pancreatic tumor model and pharmacokinetic behavior of D1T relative to TQ were evaluated. Results: D1T showed prominent inhibition of pancreatic tumor progression, significantly greater in vivo absorption, approximately 1.5-fold higher plasma concentration, higher bioavailability, reduced volume of distribution and improved clearance relative to TQ. Conclusion: Encapsulation of TQ in cationic liposomal formulation enhanced its bioavailability and anticancer efficacy against xenograft pancreatic tumor.

New Horizons in Hydrogels for Methotrexate Delivery

Since its first clinical application, methotrexate (MTX) has been widely used for the treatment of human diseases. Despite great advantages, some properties such as poor absorption, short plasma half-life and unpredictable bioavailability have led researchers to seek novel delivery systems to improve its characteristics for parenteral and oral administration. Recently, great attention has been directed to hydrogels for the preparation of MTX formulations. This review describes the potential of hydrogels for the formulation of MTX to treat cancer, rheumatoid arthritis, psoriasis and central nervous system diseases. We will delineate the state-of-the-art and promising potential of hydrogels for systemic MTX delivery as well as transdermal delivery of the drug-using hydrogel-based formulations.

Ablation of neuropilin-1 improves the therapeutic response in conventional drug-resistant glioblastoma multiforme

Glioblastoma multiforme (GBM) is a highly proliferative and locally invasive cancer with poor prognosis and a high recurrence rate. Although anti-VEGF (vascular endothelial growth factor) therapy offers short-term benefit to GBM patients, this approach fails as the tumor develops into a more invasive and drug-resistant phenotype and ultimately recurs. Recently, both glioma stemlike cells (GSCs) and brain tumor-initiating cells (BTICs) have been implicated in GBM recurrence and its resistance to therapy. We observed that patient-derived GBM cells expressing shRNAs of VEGF or neuropilin-1 (NRP-1) attenuate cancer stem cell markers, inhibit the tumor-initiating cell's neurosphere-forming capacity, and migration. Furthermore, both VEGF and NRP-1 knockdown inhibit the growth of patient-derived GBM xenografts in both zebrafish and mouse models. Interestingly, NRP-1-depleted patient-derived GBM xenografts substantially prolonged survival in mice compared to that of VEGF depletion. Our results also demonstrate that NRP-1 ablation of patient-derived GBM cells improves the sensitivity of TMZ and enhances the overall survival of the respective tumor-bearing mice. This improved outcome may provide insight into the inhibition of GBM progression and effective treatment strategies by targeting NRP-1 in addition to chemotherapy and radiotherapy.

In vivo gene delivery mediated by non-viral vectors for cancer therapy

Gene therapy by expression constructs or down-regulation of certain genes has shown great potential for the treatment of various diseases. The wide clinical application of nucleic acid materials dependents on the development of biocompatible gene carriers. There are enormous various compounds widely investigated to be used as non-viral gene carriers including lipids, polymers, carbon materials, and inorganic structures. In this review, we will discuss the recent discoveries on non-viral gene delivery systems. We will also highlight the in vivo gene delivery mediated by non-viral vectors to treat cancer in different tissue and organs including brain, breast, lung, liver, stomach, and prostate. Finally, we will delineate the state-of-the-art and promising perspective of in vivo gene editing using non-viral nano-vectors.

Novel tumor-targeted liposomes comprised of an MDM2 antagonist plus proteasome inhibitor display anti-tumor activity in a xenograft model of bortezomib-resistant Waldenstrom macroglobulinemia

Targeted drug delivery remains an active area of investigation in hematologic cancers. We have previously reported on a novel nanoparticle formulation (D1X) that can encapsulate drugs within a liposome whose lipid bilayer contains dexamethasone, which serves as a targeting ligand for drug delivery to tumor cells that express glucocorticoid receptors. We tested the activity of D1X-encapsulated bortezomib (D1XB) in combination with D1X-encapsulated nutlin (D1XN) in B-lymphoma/Waldenstrom macroglobulinemia (WM) cells. WM cells treated with D1XB + D1XN experienced cell cycle arrest, ER stress and apoptosis. In mice xenografted with bortezomib-resistant WM cells, D1XB + D1XN treatment resulted in significantly lower tumor burden compared to vehicle or nonliposomal parent drugs. In vivo biodistribution studies showed minimal uptake of D1X-based drugs in normal mice tissues. Our studies demonstrate that highly targeted delivery of both bortezomib and nutlin encapsulated in D1X nanoparticles are cytotoxic to and delay in vivo growth of bortezomib-resistant WM cells.

Targeted Dual Intervention-Oriented Drug-Encapsulated (DIODE) Nanoformulations for Improved Treatment of Pancreatic Cancer

Despite recent advancements, effective treatment for pancreatic ductal adenocarcinoma (PDAC) has remained elusive. The overall survival rate in PDAC patients has been dismally low due to resistance to standard therapies. In fact, the failure of monotherapies to provide long-term survival benefits in patients led to ascension of several combination therapies for PDAC treatment. However, these combination therapies provided modest survival improvements while increasing treatment-related adverse side effects. Hence, recent developments in drug delivery methods hold the potential for enhancing therapeutic benefits by offering cocktail drug loading and minimizing chemotherapy-associated side effects. Nanoformulations-aided deliveries of anticancer agents have been a success in recent years. Yet, improving the tumor-targeted delivery of drugs to PDAC remains a major hurdle. In the present paper, we developed several new tumor-targeted dual intervention-oriented drug-encapsulated (DIODE) liposomes. We successfully formulated liposomes loaded with gemcitabine (G), paclitaxel (P), erlotinib (E), XL-184 (c-Met inhibitor, X), and their combinations (GP, GE, and GX) and evaluated their in vitro and in vivo efficacies. Our novel DIODE liposomal formulations improved median survival in comparison with gemcitabine-loaded liposomes or vehicle. Our findings are suggestive of the importance of the targeted delivery for combination therapies in improving pancreatic cancer treatment.

Recent Advancements of Nanomedicine towards Antiangiogenic Therapy in Cancer

Angiogenesis is a process of generation of de-novo blood vessels from already existing vasculature. It has a crucial role in different physiological process including wound healing, embryonic development, and tumor growth. The methods by which therapeutic drugs inhibit tumor angiogenesis are termed as anti-angiogenesis cancer therapy. Developments of angiogenic inhibiting drugs have various limitations causing a barrier for successful treatment of cancer, where angiogenesis plays an important role. In this context, investigators developed novel strategies using nanotechnological approaches that have demonstrated inherent antiangiogenic properties or used for the delivery of antiangiogenic agents in a targeted manner. In this present article, we decisively highlight the recent developments of various nanoparticles (NPs) including liposomes, lipid NPs, protein NPs, polymer NPs, inorganic NPs, viral and bio-inspired NPs for potential application in antiangiogenic cancer therapy. Additionally, the clinical perspectives, challenges of nanomedicine, and future perspectives are briefly analyzed.

Functionalization of Nanomaterials and Their Application in Melanoma Cancer Theranostics

Treatment and cure for melanoma, the most aggressive subcategory of skin cancer, still remains a daunting challenge to be circumvented. When metastasized, it requires radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc. as its treatment, although it can be removed by surgical intervention if detected in its early stage. Development of upgraded therapeutic modalities for melanoma facilitating early diagnosis with subsequent excision before metastasis is, therefore, an urgent need. As we witnessed, nanotechnology has become instrumental with its far-reaching ramifications both in diagnosis and treatment of melanoma. In this review we are going to summarize the encouraging developments made in recent times for functionalization of nanoparticles (including liposomes, polymeric, metal, viral, protein nanoparticles) to create numerous theranostics (therapy plus diagnostics) for melanoma. We will also reflect on the melanoma statistics, molecular biology, conventional therapies, ongoing clinical trials, and future outlook.

Synchronous inhibition of mTOR and VEGF/NRP1 axis impedes tumor growth and metastasis in renal cancer

Clear cell renal cell carcinoma (ccRCC) is known for its highly vascular phenotype which is associated with elevated expression of vascular endothelial growth factor A (VEGF), also known as vascular permeability factor (VPF). Accordingly, VEGF has been an attractive target for antiangiogenic therapies in ccRCC. Two major strategies have hitherto been utilized for VEGF-targeted antiangiogenic therapies: targeting VEGF by antibodies, ligand traps or aptamers, and targeting the VEGF receptor signaling via antibodies or small-molecule tyrosine-kinase inhibitors (TKIs). In the present article we utilized two entirely different approaches: targeting mammalian target of rapamycin (mTOR) pathway that is known to be involved in VEGF synthesis, and disruption of VEGF/Neuroplin-1 (NRP1) axis that is known to activate proangiogenic and pro-tumorigenic signaling in endothelial and tumor cells, respectively. Everolimus (E) and a small-molecule inhibitor EG00229 (G) were used for the inhibition of mTOR and the disruption of VEGF/NRP1 axis, respectively. We also exploited a liposomal formulation decorated with a proprietary tumor-targeting-peptide (TTP) to simultaneously deliver these two agents in a tumor-targeted manner. The TTP-liposomes encapsulating both Everolimus and EG00229 (EG-L) demonstrated higher in vitro and in vivo growth retardation than the single drug-loaded liposomes (E-L and G-L) in two different ccRCC models and led to a noticeable reduction in lung metastasis in vivo. In addition, EG-L displayed remarkable inhibition of tumor growth in a highly aggressive syngeneic immune-competent mouse model of ccRCC developed in Balb/c mice. Taken together, this study demonstrates an effective approach to achieve improved therapeutic outcome in ccRCC.

Development of multi-drug loaded PEGylated nanodiamonds to inhibit tumor growth and metastasis in genetically engineered mouse models of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. Nanomedicine, however, offers new opportunities to facilitate drug delivery in PDAC. Our previous work has shown that poly(ethylene glycol)-functionalized nanodiamond (ND) mediated drug delivery offered a considerable improvement over free drug in PDAC. Inspired by this result and guided by molecular simulations, we opted for simultaneous loading of irinotecan and curcumin in ultra-small PEGylated NDs (ND-IRT + CUR). We observed that ND-IRT + CUR was more efficacious in killing AsPC-1 and PANC-1 cells than NDs with single drugs. Using NDs functionalized with a near-infrared (NIR) dye, we demonstrated the preferential localization of the NDs in tumors and metastatic lesions. We further demonstrate that ND-IRT + CUR is capable of producing pronounced anti-tumor effects in two different clinically relevant, immune-competent genetic models of PDAC. Cytokine profiling indicated that NDs with or without drugs downregulated the expression of IL-10, a key modulator of the tumor microenvironment. Thus, using a combination of in silico, in vitro, and in vivo approaches, we show for the first time the remarkable anti-tumor efficacy of PEGylated NDs carrying a dual payload of irinotecan plus curcumin. These results highlight the potential use of such nano-carriers in the treatment of patients with pancreatic cancer.

Recent Trends of the Bio-Inspired Nanoparticles in Cancer Theranostics

In recent years, various nanomaterials have emerged as an exciting tool in cancer theranostic applications due to their multifunctional property and intrinsic molecular property aiding effective diagnosis, imaging, and successful therapy. However, chemically synthesized nanoparticles have several issues related to the cost, toxicity and effectiveness. In this context, bio-inspired nanoparticles (NPs) held edges over conventionally synthesized nanoparticles due to their low cost, easy synthesis and low toxicity. In this present review article, a detailed overview of the cancer theranostics applications of various bio-inspired has been provided. This includes the recent examples of liposomes, lipid nanoparticles, protein nanoparticles, inorganic nanoparticles, and viral nanoparticles. Finally, challenges and the future scopes of these NPs in cancer therapy and diagnostics applications are highlighted.

Design and Evaluation of PEGylated Liposomal Formulation of a Novel Multikinase Inhibitor for Enhanced Chemosensitivity and Inhibition of Metastatic Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has one of the highest mortality rates among cancers. Chemotherapy is the standard first-line treatment, but only modest survival benefits are observed. With the advent of targeted therapies, epidermal growth factor receptor (EGFR) has been acknowledged as a prospective target in PDAC since it is overexpressed in up to 60% of cases. Similarly, the tyrosine-protein kinase Met (cMET) is also overexpressed in PDAC (27-60%) and is a prognostic marker for poor survival. Interestingly, EGFR and cMET share some common signaling pathways including PI3K/Akt and MAPK pathways. Small molecule inhibitors or bispecific antibodies that can target both EGFR and cMET are therefore emerging as novel options for cancer therapy. We previously developed a dual EGFR and cMET inhibitor (N19) that was able to inhibit tumor growth in nonsmall cell lung cancer models resistant to EGFR tyrosine kinase inhibitors (TKI). Here, we report the development of a novel liposomal formulation of N19 (LN19) and showed significant growth inhibition and increased sensitivity toward gemcitabine in the pancreatic adenocarcinoma orthotopic xenograft model. Taken together, our results suggest that LN19 can be valued as an effective combination therapy with conventional chemotherapy such as gemcitabine for PDAC patients.

Co-delivery of everolimus and vinorelbine via a tumor-targeted liposomal formulation inhibits tumor growth and metastasis in RCC

Background

Renal cell carcinoma (RCC) is notorious for its resistance towards chemotherapy and radiation therapy in general. Combination therapy is often helpful in alleviating the resistance mechanisms by targeting multiple signaling pathways but is usually more toxic than monotherapy. Co-encapsulation of multiple therapeutic agents in a tumor-targeted drug delivery platform is a promising strategy to mitigate these limitations.

Methods

A tumor-targeted liposomal formulation was prepared using phospholipids, cholesterol, DSPE-(PEG)₂₀₀₀-OMe and a proprietary tumor-targeting-peptide (TTP)-conjugated lipopeptide. An efficient method was optimized to encapsulate everolimus and vinorelbine in this liposomal formulation. Single drug-loaded liposomes were also prepared for comparison. Finally, the drug-loaded liposomes were tested in vitro and in vivo in two different RCC cell lines.

Results

The tumor-targeted liposomal formulation demonstrated excellent tumor-specific uptake. The dual drug-loaded liposomes exhibited significantly higher growth inhibition in vitro compared to the single drug-loaded liposomes in two different RCC cell lines. Similarly, the dual drug-loaded liposomes demonstrated significantly higher suppression of tumor growth compared to the single drug-loaded liposomes in two different subcutaneous RCC xenografts. In addition, the dual drug-loaded liposomes instigated significant reduction in lung metastasis in those experiments.

Conclusion

Taken together, this study demonstrates that co-delivery of everolimus and vinorelbine with a tumor-targeted liposomal formulation is an effective approach to achieve improved therapeutic outcome in RCC.