Investigating potential TRPV1 positive feedback to explain TRPV1 upregulation in airway disease states.

OBJECTIVE: The airway epithelium is a potential source of pathophysiology through activation of transient potential receptor vallinoid type 1 (TRPV1) channel. A positive feedback cycle caused by TRPV1 activity is hypothesized to induce upregulation and production of inflammatory cytokines, leading to exacerbations of chronic airway diseases. These cytokine and protein regulation effects were investigated in this study. METHODS: Healthy (BEAS-2B) and cancer-derived (Calu-3) airway epithelial cell lines were assessed for changes to TRPV1 protein expression and mRNA expression following exposure to capsaicin (5-50 µM), and TRPV1 modulators including heat (43 °C), and hydrochloric acid (pH 3.4 to pH 6.4). Cytotoxicity was measured to determine the working concentration ranges of treatment. Subsequent bronchoconstriction by TRPV1 activation with capsaicin was measured on guinea pig airway tissue to confirm locally mediated activity without the action of known neuronal inputs. RESULTS: TRPV1 protein expression was not different for all capsaicin, acidity, and heat exposures (p > 0.05), and was replicated in mRNA protein expression (p > 0.05). IL-6 and IL-8 expression were lower in BEAS-2B and Calu-3 cell lines exposed with acidity and heat (p < 0.05), but not consistently with capsaicin exposure, with potential cytotoxic effects possible. CONCLUSIONS: TRPV1 expression was present in airway epithelial cells but its expression was not changed after activation by TRPV1 activators. Thus, it was not apparent the reason for reported TRPV1 upregulation in patients with airway disease states. More complex mechanisms are likely involved and will require further investigation.

Co-Spray-Dried Urea Cross-Linked Hyaluronic Acid and Sodium Ascorbyl Phosphate as Novel Inhalable Dry Powder Formulation.

The pathogenesis and progression of several lung disorders is propagated by inflammatory and oxidative processes, which can be controlled by adjunctive inhaled therapies. The present study aimed to develop an inhalable dry powder formulation consisting of co-spray-dried urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate (SD HA-CL-SAP), a novel combination which was recently shown to possess anti-inflammatory, antioxidant, and wound healing properties. Native HA and SAP were co-spray dried (SD HA-SAP) and evaluated as control formulation. Yield (Y%) and encapsulation efficiency (EE%) were 67.0 ± 4.8% and 75.5 ± 7.2% for SD HA-SAP, 70.0 ± 1.5% and 66.5 ± 5.7% for SD HA-CL-SAP, respectively. Both formulations were shown to be suitable for lung delivery in terms of morphology, particle size (median volumetric diameter ∼ 3.4 µm), physical and thermal stability, in vitro aerosol performance - respirable fraction: 30.5 ± 0.7% for SD HA-SAP and 35.3 ± 0.3% for SD HA-CL-SAP. SAP release was investigated using Franz cells and air-interface Calu-3 cell model (>90% of SAP transported within 4 h). The innovative SD HA-CL-SAP formulation holds potential as inhalable dry powder for the treatment of inflammatory lung disorders.

In vitro characterization of physico-chemical properties, cytotoxicity, bioactivity of urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate nasal powder formulation.

An innovative lyophilized dry powder formulation consisting of urea-crosslinked hyaluronic acid (HA-CL) and sodium ascorbyl phosphate (SAP) - LYO HA-CL - SAP- was prepared and characterized in vitro for physico-chemical and biological properties. The aim was to understand if LYO HA-CL - SAP could be used as adjuvant treatment for nasal inflammatory diseases. LYO HA-CL - SAP was suitable for nasal delivery and showed to be not toxic on human nasal septum carcinoma-derived cells (RPMI 2650 cells) at the investigated concentrations. It displayed porous, polygonal particles with unimodal, narrow size distribution, mean geometric diameter of 328.3 ±â€¯27.5 µm, that is appropriate for nasal deposition with no respirable fraction and 88.7% of particles with aerodynamic diameter >14.1 µm. Additionally, the formulation showed wound healing ability on RPMI 2650 cells, and reduced interleukin-8 (IL-8) level in primary nasal epithelial cells pre-induced with lipopolysaccharide (LPS). Transport study across RPMI 2650 cells showed that HA-CL could act not only as carrier for SAP and active ingredient itself, but potentially also as mucoadhesive agent. In conclusion, these results suggest that HA-CL and SAP had anti-inflammatory activity and acted in combination to accelerate wound healing. Therefore, LYO HA-CL - SAP could be a potential adjuvant in nasal anti-inflammatory formulations.

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.

Combination of urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate for the treatment of inflammatory lung diseases: An in vitro study.

This in vitro study evaluated, for the first time, the safety and the biological activity of a novel urea-crosslinked hyaluronic acid component and sodium ascorbyl phosphate (HA-CL - SAP), singularly and/or in combination, intended for the treatment of inflammatory lung diseases. The aim was to understand if the combination HA-CL - SAP had an enhanced activity with respect to the combination native hyaluronic acid (HA) - SAP and the single SAP, HA and HA-CL components. Sample solutions displayed pH, osmolality and viscosity values suitable for lung delivery and showed to be not toxic on epithelial Calu-3 cells at the concentrations used in this study. The HA-CL - SAP displayed the most significant reduction in interleukin-6 (IL-6) and reactive oxygen species (ROS) levels, due to the combined action of HA-CL and SAP. Moreover, this combination showed improved cellular healing (wound closure) with respect to HA - SAP, SAP and HA, although at a lower rate than HA-CL alone. These preliminary results showed that the combination HA-CL - SAP could be suitable to reduce inflammation and oxidative stress in lung disorders like acute respiratory distress syndrome, asthma, emphysema and chronic obstructive pulmonary disease, where inflammation is prominent.

The use of fatty acids as absorption enhancer for pulmonary drug delivery.

A limitation in the systemic uptake of many inhalable drugs is the restricted permeation through the pulmonary epithelial layer barrier. One strategy to bypass the epithelial layer when delivering non-permeable drugs is to alter the paracellular transport, allowing the uptake of drugs into the systemic circulation. In this study, the potential of sodium decanoate (Na dec), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) as absorption enhancers has been investigated to increase pulmonary paracellular permeability by modulating epithelial cells' tight junctions. By incorporating Na dec, DHA and EPA, separately, into a nebulising formulation, the aim was to enhance the absorption of a fluorescent marker (flu-Na, used as model drug) across pulmonary epithelial cells (Calu-3). Results indicate that the aerosol performance of all the nebulizing formulations containing absorption enhancers was significantly better than control. Furthermore, the in vitro cell assays demonstrated a significant increase in paracellular transport of the fluorescent marker with Na dec and DHA formulations. This finding supports the potential use ofDHA and Na dec to enhance epithelial transport of poorly permeable drugs delivered via inhalation.

The effect of non-specific tight junction modulators on the transepithelial transport of poorly permeable drugs across airway epithelial cells.

The epithelial barrier in the respiratory system is a major obstacle for drug delivery to the systemic circulation in the lung. Epithelial barrier hinders the transport of large macromolecules or polar drugs. Essential components of this epithelial fence are physical intercellular structures termed tight junctions. Therefore, modulating tight junctions can enhance paracellular transport across epithelial barrier. In this study, the effect of some of non-specific tight junction modulators (TJMs); (Sodium (Na) decanoate, oleic acid and ethyleneglycol-bis-(ß-aminoethyl ether)-N, N'-tetraacetic acid (EGTA)) with established effect on intestinal tight junctions was evaluated for its effects on bronchial epithelial cells (Calu-3 cells). It was demonstrated that the effect of TJMs especially Na decanoate resulted in a reversible opening of tight junctions evidenced by the decrease in the transepithelial resistance. It was also demonstrated that this reduction of TEER upon exposing the epithelial cells to the TJMs resulted in a significant increase in Flu-Na (paracellular marker) and PXS25 (anti-fibrotic compound) transepithelial transport through this barrier. In conclusion, among the investigated non-specific TJMs, Na decanoate fulfilled the requirements of an effective, non-toxic and reversible tight junction modulator for Calu-3 lung epithelial cells.

Cell-based therapies for the treatment of idiopathic pulmonary fibrosis (IPF) disease.

INTRODUCTION: During the last few decades, cell-based therapies have shown great potential to treat patients with lung diseases. It has been proposed that the administration of cells into an injured lung could be considered as a therapeutic method to repair and replace lost lung tissue. Using this method, transplanted cells with the ability to proliferate and differentiate into alveolar cells, have been suggested as a therapeutic strategy for IPF treatment. AREAS COVERED: In this review, the latest investigations using various types of cells for IPF therapy have been presented. The cells studied for cell-based therapies in IPF are lung alveolar epithelial cells, lung resident stem cells and exogenous adult stem cells such as MSCs. EXPERT OPINION: After many years of investigation, the use of cell-based therapies to treat IPF is still at the experimental phase. Problems include bioethical issues, safety of cell transplantation, routes of delivery and the dose and timing of administration. Further investigations are necessary to establish the best strategy for using cell-based therapies effectively for the treatment of IPF.

Curcumin as a wound healing agent.

Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anti-coagulant and anti-infective effects. Curcumin has also been shown to have significant wound healing properties. It acts on various stages of the natural wound healing process to hasten healing. This review summarizes and discusses recently published papers on the effects of curcumin on skin wound healing. The highlighted studies in the review provide evidence of the ability of curcumin to reduce the body's natural response to cutaneous wounds such as inflammation and oxidation. The recent literature on the wound healing properties of curcumin also provides evidence for its ability to enhance granulation tissue formation, collagen deposition, tissue remodeling and wound contraction. It has become evident that optimizing the topical application of curcumin through altering its formulation is essential to ensure the maximum therapeutical effects of curcumin on skin wounds.