Development and Characterization of Folic Acid-Conjugated Amodiaquine-Loaded Nanoparticles-Efficacy in Cancer Treatment.

The objective of this study was to construct amodiaquine-loaded, folic acid-conjugated polymeric nanoparticles (FA-AQ NPs) to treat cancer that could be scaled to commercial production. In this study, folic acid (FA) was conjugated with a PLGA polymer followed by the formulation of drug-loaded NPs. The results of the conjugation efficiency confirmed the conjugation of FA with PLGA. The developed folic acid-conjugated nanoparticles demonstrated uniform particle size distributions and had visible spherical shapes under transmission electron microscopy. The cellular uptake results suggested that FA modification could enhance the cellular internalization of nanoparticulate systems in non-small cell lung cancer, cervical, and breast cancer cell types. Furthermore, cytotoxicity studies showed the superior efficacy of FA-AQ NPs in different cancer cells such as MDAMB-231 and HeLA. FA-AQ NPs had better anti-tumor abilities demonstrated via 3D spheroid cell culture studies. Therefore, FA-AQ NPs could be a promising drug delivery system for cancer therapy.

Exploring Amodiaquine's Repurposing Potential in Breast Cancer Treatment-Assessment of In-Vitro Efficacy & Mechanism of Action.

Due to the heterogeneity of breast cancer, current available treatment options are moderately effective at best. Hence, it is highly recommended to comprehend different subtypes, understand pathogenic mechanisms involved, and develop treatment modalities. The repurposing of an old FDA approved anti-malarial drug, amodiaquine (AQ) presents an outstanding opportunity to explore its efficacy in treating majority of breast cancer subtypes. Cytotoxicity, scratch assay, vasculogenic mimicry study, and clonogenic assay were employed to determine AQ's ability to inhibit cell viability, cell migration, vascular formation, and colony growth. 3D Spheroid cell culture studies were performed to identify tumor growth inhibition potential of AQ in MCF-7 and MDAMB-231 cell lines. Apoptosis assays, cell cycle analysis, RT-qPCR assays, and Western blot studies were performed to determine AQ's ability to induce apoptosis, cell cycle changes, gene expression changes, and induction of autophagy marker proteins. The results from in-vitro studies confirmed the potential of AQ as an anti-cancer drug. In different breast cancer cell lines tested, AQ significantly induces cytotoxicity, inhibit colony formation, inhibit cell migration, reduces 3D spheroid volume, induces apoptosis, blocks cell cycle progression, inhibit expression of cancer related genes, and induces LC3BII protein to inhibit autophagy. Our results demonstrate that amodiaquine is a promising drug to repurpose for breast cancer treatment, which needs numerous efforts from further studies.

Inhaled Indomethacin-Loaded Liposomes as Potential Therapeutics against Non-Small Cell Lung Cancer (NSCLC).

Most lung cancer instances are non-small cell lung cancers (NSCLC). As stated by recent literature, cycloxygenase-2 (COX-2) is upregulated in lung adenocarcinomas. COX-2 relates to enhanced cell proliferation and reduced apoptosis; both of which are essential for an invasive tumor growth and metastasis. Thus, COX-2 inhibition forms an important checkpoint. Drug repurposing and nano drug delivery systems will enable the faster and more efficacious drug development. This study was designed to prepare, characterize, and establish superior effectiveness of indomethacin (IND), (a nonselective COX-2 inhibitor) as liposomes (IND-Lip). IND-Lip were made using thin film hydration method and physicochemical properties were characterized. Cell viability was performed on NSCLC cell lines (A549, H1299 and H460) Clonogenic, spheroidal, caspase and COX-2 assays were then carried out. IND-Lip were found to have optimum physicochemical properties. Based on IC50 value of 38.4 ± 4.9 µM, A549 cells were used for further assays. From clonogenic assay, % colonies were found to be 25.5 ± 9.5% at 200 µM of IND-Lip. IND-Lip performed significantly better in ex-vivo tumor reduction in 3D spheroid assay at 200 µM concentration, compared to plain IND by Day 15. Finally, a significant inhibition of COX-2 as well as induction of caspase in all IND treated groups was observed. It is of note that liposomes demonstrated a superior efficacy in all studies compared to the plain drug. IND through liposomal delivery system can be a potentially beneficial strategy for lung carcinoma. However, further clinical studies and in-vivo research are essential to comprehend the complete view of this approach.

Repurposing clofazimine for malignant pleural mesothelioma treatment - In-vitro assessment of efficacy and mechanism of action.

AIMS: Malignant pleural mesothelioma (MPM) is a rare cancer of lungs' pleural cavity, with minimally effective therapies available. Thus, there exists a necessity for drug repurposing which is an attractive strategy for drug development in MPM. Repurposing of an old FDA-approved anti-leprotic drug, Clofazimine (CFZ), presents an outstanding opportunity to explore its efficacy in treating MPM. MAIN METHODS: Cytotoxicity, scratch assay, and clonogenic assays were employed to determine CFZ's ability to inhibit cell viability, cell migration, and colony growth. 3D Spheroid cell culture studies were performed to identify tumor growth inhibition potential of CFZ in MSTO-211H cell line. Gene expression analysis was performed using RT-qPCR assays to determine the CFZ's effect of key genes. Western blot studies were performed to determine CFZ's ability to induce apoptosis its effect to induce autophagy marker. KEY FINDINGS: CFZ showed significant cytotoxicity against both immortalized and primary patient-derived cell lines with IC50 values ranging from 3.4 µM (MSTO-211H) to 7.1 µM (HAY). CFZ significantly impaired MPM cell cloning efficiency, migration, and tumor spheroid formation. 3D Spheroid model showed that CFZ resulted in reduction in spheroid volume. RT-qPCR data showed downregulation of genes ß-catenin, BCL-9, and PRDX1; and upregulation of apoptosis markers such as PARP, Cleaved caspase 3, and AXIN2. Additionally, immunoblot analysis showed that CFZ down-regulates the expression of ß-catenin (apoptosis induction) and up-regulates p62, LC3B protein II (autophagy inhibition). SIGNIFICANCE: It can be concluded that CFZ could be a promising molecule to repurpose for MPM treatment which needs numerous efforts from further studies.

Development and characterization of inhalable transferrin functionalized amodiaquine nanoparticles - Efficacy in Non-Small Cell Lung Cancer (NSCLC) treatment.

New drug discovery and development processes encounter significant challenges including requirement of huge investments and lengthy time frames especially in cancer research field. Repurposing of old drugs against cancer provides a possible alternative while associated scale-up complexities with production of nanoparticles at industrial scale could be overcome by using a scalable nanoparticle technique. We previously described use of polymeric nanoparticles for inhaled delivery of amodiaquine (AQ) for non-small cell lung cancer (NSCLC) treatment. In this study, targeting potential of transferrin ligand conjugated inhalable AQ-loaded nanoparticles (Tf-AMQ NPs) was investigated against NSCLC. Tf-AMQ NP (liquid formulation) demonstrated an aerodynamic diameter of 4.4 ± 0.1 µm and fine particle fraction of 83.2 ± 3.0%, representing AQ deposition in the respirable region of airways. Cytotoxicity studies in NSCLC cell line with overexpressed transferrin receptors shown significant reduction in IC50 values with Tf-decorated AQ-loaded nanoparticles compared to AQ or non-targeted NPs, along with significant apoptosis induction (caspase assay) and reduced % colony growth in A549 and H1299 cells with Tf-AMQ NP. Furthermore, 3D spheroid studies (~7-fold reduction in spheroid volume compared to AMQ NPs) explained efficiency of conjugated nanoparticles in penetrating tumor core, and growth inhibition. AQ's autophagy inhibition ability significantly increased with nanoparticle encapsulation and transferrin conjugation. In conclusion, amodiaquine can be an assuring candidate for repurposing to consider for NSCLC treatment while delivering inhalable transferrin conjugated nanoparticles developed using a scalable HPH process to the target site, thus reducing the dose, side effects.

Repurposing Bedaquiline for Effective Non-Small Cell Lung Cancer (NSCLC) Therapy as Inhalable Cyclodextrin-Based Molecular Inclusion Complexes.

There is growing evidence that repurposed drugs demonstrate excellent efficacy against many cancers, while facilitating accelerated drug development process. In this study, bedaquiline (BDQ), an FDA approved anti-mycobacterial agent, was repurposed and an inhalable cyclodextrin complex formulation was developed to explore its anti-cancer activity in non-small cell lung cancer (NSCLC). A sulfobutyl ether derivative of ß-cyclodextrin (SBE-ß-CD) was selected based on phase solubility studies and molecular modeling to prepare an inclusion complex of BDQ and cyclodextrin. Aqueous solubility of BDQ was increased by 2.8 × 103-fold after complexation with SBE-ß-CD, as compared to its intrinsic solubility. Solid-state characterization studies confirmed the successful incorporation of BDQ in the SBE-ß-CD cavity. In vitro lung deposition study results demonstrated excellent inhalable properties (mass median aerodynamic diameter: 2.9 ± 0.6 µm (<5 µm) and fine particle fraction: 83.3 ± 3.8%) of BDQ-CD complex. Accelerated stability studies showed BDQ-CD complex to be stable up to 3 weeks. From cytotoxicity studies, a slight enhancement in the anti-cancer efficacy was observed with BDQ-cyclodextrin complex, compared to BDQ alone in H1299 cell line. The IC50 values for BDQ and BDQ-CD complex were found to be ~40 µM in case of H1299 cell line at 72 h, whereas BDQ/BDQ-CD were not found to be cytotoxic up to concentrations of 50 µM in A549 cell line. Taken together, BDQ-CD complex offers a promising inhalation strategy with efficient lung deposition and cytotoxicity for NSCLC treatment.

Afatinib-loaded inhalable PLGA nanoparticles for localized therapy of non-small cell lung cancer (NSCLC)-development and in-vitro efficacy.

Afatinib (AFA) is a potent aniline-quinazoline derivative, approved by the Food and Drug Administration (FDA) in 2013, as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). However, its clinical application is highly limited by its poor solubility, and consequently low bioavailability. We hypothesize that loading of AFA into biodegradable PLGA nanoparticles for localized inhalational drug delivery will be instrumental in improving therapeutic outcomes in NSCLC patients. Formulated AFA nanoparticles (AFA-NP) were evaluated for physicochemical properties (particle size: 180.2 ± 15.6 nm, zeta potential: - 23.1 ± 0.2 mV, % entrapment efficiency: 34.4 ± 2.3%), formulation stability, in-vitro aerosol deposition behavior, and anticancer efficacy. Stability studies revealed the physicochemical stability of AFA-NP. Moreover, AFA-NP exhibited excellent inhalable properties (mass median aerodynamic diameter (MMAD): 4.7 ± 0.1 µm; fine particle fraction (FPF): 77.8 ± 4.3%), indicating efficient particle deposition in deep lung regions. With respect to in-vitro drug release, AFA-NP showed sustained drug release with cumulative release of 56.8 ± 6.4% after 48 h. Cytotoxic studies revealed that encapsulation of AFA into PLGA nanoparticles significantly enhanced its cytotoxic potential in KRAS-mutated NSCLC cell lines (A549, H460). Cellular uptake studies revealed enhanced internalization of coumarin-loaded nanoparticles compared to plain coumarin in A549. In addition, 3D tumor spheroid studies demonstrated superior efficacy of AFA-NP in tumor penetration and growth inhibition. To conclude, we have established in-vitro efficacy of afatinib-loaded PLGA nanoparticles as inhalable NSCLC therapy, which will be of great significance when designing preclinical and clinical studies. Graphical abstract.

Repurposing Quinacrine for Treatment of Malignant Mesothelioma: In-Vitro Therapeutic and Mechanistic Evaluation.

Malignant mesothelioma (MM) is a rare type of cancer primarily affecting mesothelial cells lining the pleural cavity. In this study, we propose to repurpose quinacrine (QA), a widely approved anti-malarial drug, for Malignant Pleural Mesothelioma (MPM) treatment. QA demonstrates high degree of cytotoxicity against both immortalized and primary patient-derived cell lines with sub-micromolar 50% inhibitory concentration (IC50) values ranging from 1.2 µM (H2452) to 5.03 µM (H28). Further, QA also inhibited cellular migration and colony formation in MPM cells, demonstrated using scratch and clonogenic assays, respectively. A 3D-spheroid cell culture experiment was performed to mimic in-vivo tumor conditions, and QA was reported to be highly effective in this simulated cellular model. Anti-angiogenic properties were also discovered for QA. Autophagy inhibition assay was performed, and results revealed that QA successfully inhibited autophagy process in MPM cells, which has been cited to be one of the survival pathways for MPM. Annexin V real-time apoptosis study revealed significant apoptotic induction in MPM cells following QA treatment. Western blots confirmed inhibition of autophagy and induction of apoptosis. These studies highlight anti-mesothelioma efficacy of QA at low doses, which can be instrumental in developing it as a stand-alone treatment strategy for MPM.

Utilizing drug repurposing against COVID-19 - Efficacy, limitations, and challenges.

The recent outbreak of Coronavirus disease (COVID-19), first in Eastern Asia and then essentially across the world has been declared a pandemic by the WHO. COVID-19 is caused by a novel virus SARS-CoV2 (2019-nCoV), against which there is currently no vaccine available; and current antiviral therapies have failed, causing a very high mortality rate. Drug repurposing i.e. utilizing an approved drug for different indication, offers a time- and cost-efficient alternative for making new therapies available to patients. Although there are several reports presenting novel approaches to treat COVID-19, still an attentive review of previous scientific literature is essential to overcome their failure to exhibit efficacy. There is an urgent need to provide a comprehensive outlook toward utilizing drug repurposing as a tool for discovery of new therapies against COVID-19. In this article, we aim to provide a to-the-point review of current literature regarding efficacy of repurposed drugs against COVID-19 and other respiratory infections caused by coronaviruses. We have briefly discussed COVID-19 epidemiology, and then have discussed drug repurposing approaches and examples, specific to respiratory viruses. Limitations of utilization of repurposed drug molecules such as dosage regimen and associated challenges such as localized delivery in respiratory tract have also been discussed in detail.

Inhalable resveratrol-cyclodextrin complex loaded biodegradable nanoparticles for enhanced efficacy against non-small cell lung cancer.

Resveratrol (RES), a natural polyphenol in fruits, has shown promising anti-cancer properties. Due to its relative low toxicity which limits the adverse effects observed for conventional chemotherapeutics, RES has been proposed as an alternative. However, the therapeutic applications of RES have been limited due to low water solubility, as well as chemical and physical instability. This study investigated enhancing the anti-cancer activity of RES against non-small-cell-lung-cancer (NSCLC) by complexing with sulfobutylether-ß-cyclodextrin (CD-RES) and loading onto polymeric nanoparticles (NPs). The physicochemical properties of the CD-RES NPs were then characterized. The CD-RES inclusion complex increased the water solubility of RES by ~66-fold. CD-RES NPs demonstrated very good aerosolization potential with a mass median aerodynamic diameter of 2.20 µm. Cell-based studies demonstrated improved therapeutic efficacy of CD-RES NPs compared to RES. This included enhanced cellular uptake, cytotoxicity, and apoptosis, while retaining antioxidant activity. The 3D spheroid study indicated an intensified anti-cancer effect of CD-RES NPs. Altogether, these findings marked CD-RES NPs as a potential inhalable delivery system of RES for the treatment NSCLC.

Cyclodextrin Complexation for Enhanced Stability and Non-invasive Pulmonary Delivery of Resveratrol-Applications in Non-small Cell Lung Cancer Treatment.

Pulmonary drug delivery is a noninvasive therapeutic approach that offers many advantages including localized drug delivery and higher patient compliance. As with all formulations, the low aqueous solubility of a drug often poses a challenge in the formulation development. Thus, strategies such as cyclodextrin (CD) complexation have been utilized to overcome this challenge. Resveratrol (RES), a natural stilbene, has shown abundant anti-cancer properties. Due to many drawbacks of conventional chemotherapeutics, RES has been proposed as an emerging alternative with promising pharmacological effects. However, RES has limited therapeutic applications due to low water solubility, chemical stability, and bioavailability. This study was aimed at developing an inhalable therapy that would increase the aqueous solubility and stability of RES by complexation with sulfobutylether-ß-cyclodextrin (SBECD). Phase solubility profiles indicated an optimal stoichiometric inclusion complex at 1:1 (SBECD:RES) ratio for formulation considerations. Physiochemical characterizations were performed to analyze CD-RES. Stability studies at pH 7.4 and in plasma indicated significant improvement in RES stability after complexation, with a much longer half-life. The mass median aerodynamic diameter (MMAD) of CD-RES was 2.6 ± 0.7 µm and fine particle fraction (FPF) of 83.4 ± 3.0% are suitable for pulmonary delivery and efficient deposition. Lung cancer was selected as the respiratory model disease, owing to its high relevance as the major cause of cancer deaths worldwide. Cell viability studies in 5 non-small-cell-lung-cancer (NSCLC) cell lines suggest CD-RES retained significant cytotoxic potential of RES. Taken together, CD-RES proves to be a promising inhalation treatment for NSCLC.

Development of pharmaceutically scalable inhaled anti-cancer nanotherapy - Repurposing amodiaquine for non-small cell lung cancer (NSCLC).

New drug and dosage form development faces significant challenges, especially in oncology, due to longer development cycle and associated scale-up complexities. Repurposing of existing drugs with potential anti-cancer activity into new therapeutic regimens provides a feasible alternative. In this project, amodiaquine (AQ), an anti-malarial drug, has been explored for its anti-cancer efficacy through formulating inhalable nanoparticulate systems using high-pressure homogenization (HPH) with scale-up feasibility and high reproducibility. A 32 multifactorial design was employed to better understand critical processes (probe homogenization speed while formulating coarse emulsion) and formulation parameters (concentration of cationic polymer in external aqueous phase) so as to ensure product quality with improved anticancer efficacy in non-small cell lung cancer (NSCLC). Optimized AQ loaded nanoparticles (AQ NP) were evaluated for physicochemical properties, stability profile, in-vitro aerosol deposition behavior, cytotoxic potential against NSCLC cells in-vitro and in 3D simulated tumor spheroid model. The highest probe homogenization speed (25,000 rpm) resulted in lower particle size. Incorporation of cationic polymer, polyethylenimine (0.5% w/v) resulted in high drug loading efficiencies at optimal drug quantity of 5 mg. Formulated nanoparticles (liquid state) exhibited an aerodynamic diameter of 4.7 ± 0.1 µm and fine particle fraction of 81.0 ± 9.1%, indicating drug deposition in the respirable airways. Cytotoxicity studies in different NSCLC cell lines revealed significant reduction in IC50 values with AQ-loaded nanoparticles compared to plain drug, along with significant cell migration inhibition (scratch assay) and reduced % colony growth (clonogenic assay) in A549 cells with AQ NP. Moreover, 3D simulated spheroid studies revealed efficacy of nanoparticles in penetration to tumor core, and growth inhibition. AQ's autophagy inhibition ability significantly increased (increased LC3B-II levels) with nanoparticle encapsulation, along with moderate improvement in apoptosis induction (Caspase-3 levels). No impact was observed on HUVEC angiogenesis suggesting alternative anticancer mechanisms. To conclude, amodiaquine can be a promising candidate for repurposing to treat NSCLC while delivering inhalable nanoparticles developed using a scalable HPH process. Despite the involvement of complex parameters, application of DoE has simplified the process of product and process optimization.

Nanotechnology Based Repositioning of an Anti-Viral Drug for Non-Small Cell Lung Cancer (NSCLC).

PURPOSE: Nelfinavir (NFV), a FDA approved antiretroviral drug, has been reported to exhibit cancer cells growth inhibition and increased apoptosis. However, it requires a higher dose leading to toxicity, thus limiting its potential clinical translation. We aim to develop biodegradable (poly (lactic-co-glycolic acid)) PLGA nanoparticles of nelfinavir and determine their efficacy to treat non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: HIV protease inhibitor, NFV, was loaded into PLGA nanoparticles by double emulsion/solvent evaporation method; and nanoparticles were characterized for physicochemical characteristics including morphology and intracellular uptake. Their anti-cancer efficacy in NSCLC was assessed by in vitro assays including cytotoxicity, cellular migration, colony formation; and 3D spheroid culture mimicking in-vivo tumor microenvironment. Studies were also conducted to elucidate effects on molecular pathways including apoptosis, autophagy, and endoplasmic stress. RESULTS: NFV loaded PLGA nanoparticles (NPs) were found to have particle size: 191.1 ± 10.0 nm, zeta potential: -24.3 ± 0.9 mV, % drug loading: 2.5 ± 0.0%; and entrapment efficiency (EE): 30.1 ± 0.5%. NFV NP inhibited proliferation of NSCLC cells compared to NFV and exhibited significant IC50 reduction. From the caspase-dependent apoptosis assays and western blot studies (upregulation of ATF3), it was revealed that NFV NP significantly induced ER stress marker ATF3, cleaved PARP and further caused autophagy inhibition (LC3BII upregulation) leading to increased cellular death. In addition, NFV NP were found to be more efficacious in penetrating solid tumors in ex-vivo studies compared to plain NFV. CONCLUSIONS: Nelfinavir, a lead HIV protease inhibitor can be repositioned as a NSCLC therapeutic through nanoparticulate delivery. Given its ability to induce apoptosis and efficient tumor penetration capability, NFV loaded PLGA nanoparticulate systems provide a promising delivery system in NSCLC treatment.

Metformin-loaded chitosomes for treatment of malignant pleural mesothelioma - A rare thoracic cancer.

The purpose of this study was to design and evaluate chitosan dispersed lipid vesicles (chitosomes) as potential delivery carriers for repurposing metformin (Met) against malignant pleural mesothelioma. Chitosomes were prepared by directly hydrating the thin lipid film using chitosan solution as hydration medium, instead of using it as a coating agent. Developed chitosomes demonstrated spherical morphology, positive surface charge (~30 mV) and ~60% encapsulation efficiency. The calorimetric studies and X-ray diffraction pattern of Met-loaded chitosomes confirmed the successful encapsulation of Met inside the chitosome vesicles. Optimized chitosome formulation showed ~70% drug release in 72 h, displaying prolonged and controlled release of drug. Results demonstrated that Met encapsulated chitosomes possessed enhanced cellular internalization and improved cytotoxic potential. Our findings also supported inhibitory activity of chitosomes against metastatic property of pleural mesothelioma cells. The in-vitro tumor simulation studies further established anti-tumor activity of Met encapsulated chitosomes as supported by reduction in tumor volume and presence of minimal viable cells in tumor mass. The obtained results establish the effectiveness of chitosomes as delivery carrier for Met as treatment alternative for malignant pleural mesothelioma.

Systematic Development and Optimization of Inhalable Pirfenidone Liposomes for Non-Small Cell Lung Cancer Treatment.

Non-small cell lung cancer (NSCLC) is a global disorder, treatment options for which remain limited with resistance development by cancer cells and off-target events being major roadblocks for current therapies. The discovery of new drug molecules remains time-consuming, expensive, and prone to failure in safety/efficacy studies. Drug repurposing (i.e., investigating FDA-approved drug molecules for use against new indications) provides an opportunity to shorten the drug development cycle. In this project, we propose to repurpose pirfenidone (PFD), an anti-fibrotic drug, for NSCLC treatment by encapsulation in a cationic liposomal carrier. Liposomal formulations were optimized and evaluated for their physicochemical properties, in-vitro aerosol deposition behavior, cellular internalization capability, and therapeutic potential against NSCLC cell lines in-vitro and ex-vivo. Anti-cancer activity of PFD-loaded liposomes and molecular mechanistic efficacy was determined through colony formation (1.5- to 2-fold reduction in colony growth compared to PFD treatment in H4006, A549 cell lines, respectively), cell migration, apoptosis and angiogenesis assays. Ex-vivo studies using 3D tumor spheroid models revealed superior efficacy of PFD-loaded liposomes against NSCLC, as compared to plain PFD. Hence, the potential of inhalable liposome-loaded pirfenidone in NSCLC treatment has been established in-vitro and ex-vivo, where further studies are required to determine their efficacy through in vivo preclinical studies followed by clinical studies.

Sorafenib Loaded Inhalable Polymeric Nanocarriers against Non-Small Cell Lung Cancer.

PURPOSE: This exploration is aimed at developing sorafenib (SF)-loaded cationically-modified polymeric nanoparticles (NPs) as inhalable carriers for improving the therapeutic efficacy of SF against non-small cell lung cancer (NSCLC). METHODS: The NPs were prepared using a solvent evaporation technique while incorporating cationic agents. The optimized NPs were characterized by various physicochemical parameters and evaluated for their aerosolization properties. Several in-vitro evaluation studies were performed to determine the efficacy of our delivery carriers against NSCLC cells. RESULTS: Optimized nanoparticles exhibited an entrapment efficiency of ~40%, <200 nm particle size and a narrow poly-dispersity index. Cationically-modified nanoparticles exhibited enhanced cellular internalization and cytotoxicity (~5-fold IC50 reduction vs SF) in various lung cancer cell types. The inhalable nanoparticles displayed efficient aerodynamic properties (MMAD ~ 4 µM and FPF >80%). In-vitro evaluation also resulted in a superior ability to inhibit cancer metastasis. 3D-tumor simulation studies further established the anti-cancer efficacy of NPs as compared to just SF. CONCLUSION: The localized delivery of SF-loaded nanoparticles resulted in improved anti-tumor activity as compared to SF alone. Therefore, this strategy displays great potential as a novel treatment approach against certain lung cancers.

Development of inhalable quinacrine loaded bovine serum albumin modified cationic nanoparticles: Repurposing quinacrine for lung cancer therapeutics.

Drug repurposing is on the rise as an atypical strategy for discovery of new molecules, involving use of pre-existing molecules for a different therapeutic application than the approved indication. Using this strategy, the current study aims to leverage effects of quinacrine (QA), a well-known anti-malarial drug, for treatment of non-small cell lung cancer (NSCLC). For respiratory diseases, designing a QA loaded inhalable delivery system has multiple advantages over invasive delivery. QA-loaded nanoparticles (NPs) were thus prepared using polyethyleneimine (PEI) as a cationic stabilizer. While the use of PEI provided cationic charge on the particles, it also mediated a burst release of QA and demonstrated potential particle toxicity. These concerns were circumvented by coating nanoparticles with bovine serum albumin (BSA), which retained the cationic charge, reduced NP toxicity and modulated QA release. Prepared nanoparticles were characterized for physicochemical properties along with their aerosolization potential. Therapeutic efficacy of the formulations was tested in different NSCLC cells. Mechanism of higher anti-proliferation was evaluated by studying cell cycle profile, apoptosis and molecular markers involved in the progression of lung cancer. BSA coated QA nanoparticles demonstrated good aerosolization potential with a mass median aerodynamic diameter of significantly less than 5 µm. Nanoparticles also demonstrated improved therapeutic efficacy against NSCLC cells in terms of low IC50 values, cell cycle arrest at G2/M phase and autophagy inhibition leading to increased apoptosis. BSA coated QA NPs also demonstrated enhanced therapeutic efficacy in a 3D cell culture model. The present study thus lays solid groundwork for pre-clinical and eventual clinical studies as a standalone therapy and in combination with existing chemotherapeutics.

Metformin-Encapsulated Liposome Delivery System: An Effective Treatment Approach against Breast Cancer.

This study aimed at developing metformin hydrochloride (Met) encapsulated liposomal vesicles for enhanced therapeutic outcomes at reduced doses against breast cancer. Liposomal Met was prepared using thin-film hydration through various loading methods; passive loading, active loading, and drug-loaded lipid film. The drug-loaded film method exhibited maximum entrapment efficiency (~65%) as compared to active loading (~25%) and passive loading (~5%) prepared Met-loaded liposomes. The therapeutic efficacy of these optimized liposomes was evaluated for cellular uptake, cytotoxicity, inhibition of metastatic activity, and apoptosis-inducing activity. Results demonstrated significantly superior activity of positively charged liposomes resulting in reduced IC50 values, minimal cell migration activity, reduced colony formation, and profound apoptosis-induced activity in breast cancer cells as compared to Met. The anti-tumor activity was investigated using a clinically relevant in vitro tumor simulation model, which confirmed enhanced anti-tumorigenic property of liposomal Met over Met itself. To the authors' knowledge, this is the first report of Met-loaded liposomes for improving the efficacy and therapeutic effect of Met against breast cancer. With the results obtained, it can be speculated that liposomal encapsulation of metformin offers a potentially promising and convenient approach for enhanced efficacy and bioavailability in breast cancer treatment.

Drug repurposing: a promising tool to accelerate the drug discovery process.

Traditional drug discovery and development involves several stages for the discovery of a new drug and to obtain marketing approval. It is necessary to discover new strategies for reducing the drug discovery time frame. Today, drug repurposing has gained importance in identifying new therapeutic uses for already-available drugs. Typically, repurposing can be achieved serendipitously (unintentional fortunate observations) or through systematic approaches. Numerous strategies to discover new indications for FDA-approved drugs are discussed in this article. Drug repurposing has therefore become a productive approach for drug discovery because it provides a novel way to explore old drugs for new use but encounters several challenges. Some examples of different approaches are reviewed here.