New dry powders for inhalation containing temozolomide-based nanomicelles for improved lung cancer therapy

Customizable Resveratrol Spray-dried Micro-composites for Inhalation as a Promising Contender for Treatment of Idiopathic Pulmonary Fibrosis

The past decades have witnessed tremendous expansion in utilization of plant-derived medicines as resveratrol (RES) in treating several diseases like idiopathic pulmonary fibrosis (IPF). RES can exhibit its role in treating IPF via its outstanding antioxidant and anti-inflammatory activities. The goal of this work was to formulate RES-loaded spray-dried composite microparticles (SDCMs) suitable for pulmonary delivery via dry powder inhaler (DPI). They were prepared by spray drying of a previously prepared RES-loaded bovine serum albumin nanoparticles (BSA NPs) dispersion using different carriers. RES-loaded BSA NPs, prepared by the desolvation technique, acquired suitable particle size of 177.67±0.95 nm and entrapment efficiency of 98.7±0.35% with perfectly uniform size distribution and high stability. Considering the attributes of the pulmonary route, NPs were co-spray dried with compatible carriers viz. mannitol, dextran, trehalose, leucine, glycine, aspartic acid, and glutamic acid to fabricate SDCMs. All formulations showed suitable mass median aerodynamic diameter less than 5 µm; that is suitable for deep lung deposition. However, the best aerosolization behavior was attained from using leucine with fine particle fraction (FPF) of 75.74%, followed by glycine with FPF of 54.7%. Finally, a pharmacodynamic study was conducted on bleomycin-induced mice, and it strongly revealed the role of the optimized formulations in alleviating PF through suppressing the levels of hydroxyproline, tumor necrosis factor-α and matrix metalloproteinase-9 with obvious improvements in the treated lung histopathology. These findings indicate that in addition to leucine, the glycine amino acid, which is not commonly used yet, is very promising in the formulation of DPIs.

Thermodynamic Solubility Profile of Temozolomide in Different Commonly Used Pharmaceutical Solvents

The solubility parameters, and solution thermodynamics of temozolomide (TMZ) in 10 frequently used solvents were examined at five different temperatures. The maximum mole fraction solubility of TMZ was ascertained in dimethyl sulfoxide (1.35 × 10⁻²), followed by that in polyethylene glycol-400 (3.32 × 10⁻³) > Transcutol^® (2.89 × 10⁻³) > ethylene glycol (1.64 × 10⁻³) > propylene glycol (1.47 × 10⁻³) > H₂O (7.70 × 10⁻⁴) > ethyl acetate (5.44 × 10⁻⁴) > ethanol (1.80 × 10⁻⁴) > isopropyl alcohol (1.32 × 10⁻⁴) > 1-butanol (1.07 × 10⁻⁴) at 323.2 K. An analogous pattern was also observed for the other investigated temperatures. The quantitated TMZ solubility values were regressed using Apelblat and Van’t Hoff models and showed overall deviances of 0.96% and 1.33%, respectively. Apparent thermodynamic analysis indicated endothermic, spontaneous, and entropy-driven dissolution of TMZ in all solvents. TMZ solubility data may help to formulate dosage forms, recrystallize, purify, and extract/separate TMZ.

Inhalation delivery of repurposed drugs for lung cancer: Approaches, benefits and challenges

Lung cancer (LC) is one of the leading causes of mortality accounting for almost 25% of cancer deaths throughout the world. The shortfall of affordable and effective first-line chemotherapeutics, the existence of resistant tumors, and the non-optimal route of administration contribute to poor prognosis and high mortality in LC. Administration of repurposed non-oncology drugs (RNODs) loaded in nanocarriers (NCs) via inhalation may prove as an effective alternative strategy to treat LC. Furthermore, their site-specific release through inhalation route using an appropriate inhalation device would offer improved therapeutic efficacy, thereby reducing mortality and improving patients' quality of life. The current manuscript offers a comprehensive overview on use of RNODs in LC treatment with an emphasis on their inhalation delivery and the associated challenges. The role of NCs to improve lung deposition and targeting of RNODs via inhalation are also elaborated. In addition, information about various RNODs in clinical trials for the treatment of LC, possibility for repurposing phytoceuticals against LC via inhalation and the bottlenecks associated with repurposing RNODs against cancer are also highlighted. Based on the reported studies covered in this manuscript, it was understood that delivery of RNODs via inhalation has emerged as a propitious approach. Hence, it is anticipated to provide effective first-line treatment at an affordable cost in debilitating LC from low and middle-income countries (LMIC).

Pulmonary delivery of cationic liposomal hydroxycamptothecin and 5-aminolevulinic acid for chemo-sonodynamic therapy of metastatic lung cancer

Sonodynamic therapy (SDT) has been tried for cancer treatment; however, sonosensitizers are usually administered by injection, leading to low distribution in the tumor tissue and compromised therapeutic effect, even serious side effect. Here, we combined cationic liposomal hydroxycamptothecin (CLH) and 5-aminolevulinic acid (5-ALA) via intratracheal (i.t.) administration for the chemo-sonodynamic (Chemo-SDT) therapy of metastatic lung cancer. CLH was prepared from HCPT and the lipid mixture of soybean lecithin/cholesterol/octadecylamine with a film method. The optimal pre-incubation time of 5-ALA with tumor cells before ultrasound exposure was 4 h, for sake of sonosensitizer accumulation, i.e., protoporphyrin IX, the metabolite of 5-ALA. In vitro studies showed the higher cytotoxicity of Chemo-SDT compared to the other treatments, including i.t. CLH, intravenous (i.v.) CLH, and SDT alone. The combination of pulmonary delivery and Chemo-SDT showed the highest anticancer effect among the treatments on the metastatic lung tumor-bearing mice, which was judged according to the tumor appearance and pathological sections. The major anticancer mechanism of Chemo-SDT included the improved apoptosis of cancer cells and the enhanced production of reactive oxygen species, and more importantly, the synergy of chemotherapy and SDT. Pulmonary delivery of chemotherapeutics and sonosensitizers is a promising strategy for the treatment of lung cancer.

Inhaled Micro/Nanoparticulate Anticancer Drug Formulations: An Emerging Targeted Drug Delivery Strategy for Lung Cancers

Local delivery of drug to the target organ via inhalation offers enormous benefits in the management of many diseases. Lung cancer is the most common of all cancers and it is the leading cause of death worldwide. Currently available treatment systems (intravenous or oral drug delivery) are not efficient in accumulating the delivered drug into the target tumor cells and are usually associated with various systemic and dose-related adverse effects. The pulmonary drug delivery technology would enable preferential accumulation of drug within the cancer cell and thus be superior to intravenous and oral delivery in reducing cancer cell proliferation and minimising the systemic adverse effects. Site-specific drug delivery via inhalation for the treatment of lung cancer is both feasible and efficient. The inhaled drug delivery system is non-invasive, produces high bioavailability at a low dose and avoids first pass metabolism of the delivered drug. Various anticancer drugs including chemotherapeutics, proteins and genes have been investigated for inhalation in lung cancers with significant outcomes. Pulmonary delivery of drugs from dry powder inhaler (DPI) formulation is stable and has high patient compliance. Herein, we report the potential of pulmonary drug delivery from dry powder inhaler (DPI) formulations inhibiting lung cancer cell proliferation at very low dose with reduced unwanted adverse effects.

Constitutional mismatch repair-deficiency: current problems and emerging therapeutic strategies

Mismatch repair (MMR) proteins remove errors from newly synthesized DNA, improving the fidelity of DNA replication. A loss of MMR causes a mutated phenotype leading to a predisposition to cancer. In the last 20 years, an increasing number of patients have been described with biallelic MMR gene mutations in which MMR defects are inherited from both parents. This leads to a syndrome with recessive inheritance, referred to as constitutional mismatch repair-deficiency (CMMRD). CMMRD is a rare childhood cancer predisposition syndrome. The spectrum of CMMRD tumours is broad and CMMRD-patients possess a high risk of multiple cancers including hematological, brain and intestinal tumors. The severity of CMMRD is highlighted by the fact that patients do not survive until later life, emphasising the requirement for new therapeutic interventions. Many tumors in CMMRD-patients are hypermutated leading to the production of truncated protein products termed neoantigens. Neoantigens are recognized as foreign by the immune system and induce antitumor immune responses. There is growing evidence to support the clinical efficacy of neoantigen based vaccines and immune checkpoint inhibitors (collectively referred to as immunotherapy) for the treatment of CMMRD cancers. In this review, we discuss the current knowledge of CMMRD, the advances in its diagnosis, and the emerging therapeutic strategies for CMMRD-cancers.

The potential to treat lung cancer via inhalation of repurposed drugs

Lung cancer is a highly invasive and prevalent disease with ineffective first-line treatment and remains the leading cause of cancer death in men and women. Despite the improvements in diagnosis and therapy, the prognosis and outcome of lung cancer patients is still poor. This could be associated with the lack of effective first-line oncology drugs, formation of resistant tumors and non-optimal administration route. Therefore, the repurposing of existing drugs currently used for different indications and the introduction of a different method of drug administration could be investigated as an alternative to improve lung cancer therapy. This review describes the rationale and development of repositioning of drugs for lung cancer treatment with emphasis on inhalation. The review includes the current progress of repurposing non-cancer drugs, as well as current chemotherapeutics for lung malignancies via inhalation. Several potential non-cancer drugs such as statins, itraconazole and clarithromycin, that have demonstrated preclinical anti-cancer activity, are also presented. Furthermore, the potential challenges and limitations that might hamper the clinical translation of repurposed oncology drugs are described.

Dual-Drug Containing Core-Shell Nanoparticles for Lung Cancer Therapy

Late-stage diagnosis of lung cancer occurs ~95% of the time due to late manifestation of its symptoms, necessitating rigorous treatment following diagnosis. Existing treatment methods are limited by lack of specificity, systemic toxicity, temporary remission, and radio-resistance in lung cancer cells. In this research, we have developed a folate receptor-targeting multifunctional dual drug-loaded nanoparticle (MDNP) containing a poly(N-isopropylacrylamide)-carboxymethyl chitosan shell and poly lactic-co-glycolic acid (PLGA) core for enhancing localized chemo-radiotherapy to effectively treat lung cancers. The formulation provided controlled releases of the encapsulated therapeutic compounds, NU7441 - a potent radiosensitizer, and gemcitabine - an FDA approved chemotherapeutic drug for lung cancer chemo-radiotherapy. The MDNPs showed biphasic NU7441 release and pH-dependent release of gemcitabine. These nanoparticles also demonstrated good stability, excellent hemocompatibility, outstanding in vitro cytocompatibility with alveolar Type I cells, and dose-dependent caveolae-mediated in vitro uptake by lung cancer cells. In addition, they could be encapsulated with superparamagnetic iron oxide (SPIO) nanoparticles and visualized by MRI in vivo. Preliminary in vivo results demonstrated the low toxicity of these particles and their use in chemo-radiotherapy to effectively reduce lung tumors. These results indicate that MDNPs can potentially be used as nano-vehicles to provide simultaneous chemotherapy and radiation sensitization for lung cancer treatment.

Pulmonary delivery of nanoparticle chemotherapy for the treatment of lung cancers: challenges and opportunities

Lung cancer is the second most prevalent and the deadliest among all cancer types. Chemotherapy is recommended for lung cancers to control tumor growth and to prolong patient survival. Systemic chemotherapy typically has very limited efficacy as well as severe systemic adverse effects, which are often attributed to the distribution of anticancer drugs to non-targeted sites. In contrast, inhalation routes permit the delivery of drugs directly to the lungs providing high local concentrations that may enhance the anti-tumor effect while alleviating systemic adverse effects. Preliminary studies in animals and humans have suggested that most inhaled chemotherapies are tolerable with manageable pulmonary adverse effects, including cough and bronchospasm. Promoting the deposition of anticancer drugs in tumorous cells and minimizing access to healthy lung cells can further augment the efficacy and reduce the risk of local toxicities caused by inhaled chemotherapy. Sustained release and tumor localization characteristics make nanoparticle formulations a promising candidate for the inhaled delivery of chemotherapeutic agents against lung cancers. However, the physiology of respiratory tracts and lung clearance mechanisms present key barriers for the effective deposition and retention of inhaled nanoparticle formulations in the lungs. Recent research has focused on the development of novel formulations to maximize lung deposition and to minimize pulmonary clearance of inhaled nanoparticles. This article systematically reviews the challenges and opportunities for the pulmonary delivery of nanoparticle formulations for the treatment of lung cancers.

Development and evaluation of well-tolerated and tumor-penetrating polymeric micelle-based dry powders for inhaled anti-cancer chemotherapy

Despite the direct access to the lung offered by the inhalation route, drug penetration into lung tumors could remain an important issue. In this study, folate-polyethylene glycol-hydrophobically-modified dextran (F-PEG-HMD) micelles were developed as an effective pulmonary drug delivery system to reach and penetrate lung tumors and cancer cells. The F-PEG-HMD micelles were able to enter HeLa and M109-HiFR, two folate receptor-expressing cancer cell lines, in vitro, and in vivo after administration by inhalation to orthotopic M109-HiFR lung tumor grafted mice. Paclitaxel-loaded F-PEG-HMD micelles characterized in PBS by a Z-average diameter of ∼50 nm and a zeta potential of ∼-4 mV were prepared with an encapsulation efficiency of ∼100%. The loaded micelles reduced HeLa and M109-HiFR cell growth, with half maximal inhibitory concentrations of 37 and 150 nM, respectively. Dry powders embedding the paclitaxel-loaded F-PEG-HMD micelles were developed by spray-drying. In vitro, good deposition profiles were obtained, with a fine particle fraction of up to 50% and good ability to re-disperse the micelles in physiological buffer. A polymeric micelle-based dry powder without paclitaxel was well-tolerated in vivo, as assessed in healthy mice by determination of total protein content, cell count, and cytokine IL-1β, IL-6, and TNF-α concentrations in bronchoalveolar lavage fluids.