Exhaled breath condensate pH in patients with lung cancer

Aerosolized Niosome Formulation Containing Gemcitabine and Cisplatin for Lung Cancer Treatment: Optimization, Characterization and In Vitro Evaluation

Gemcitabine (Gem) and cisplatin (Cis) are currently being used for lung cancer treatment, but they are highly toxic in high dosages. This research aimed to develop a niosome formulation containing a low-dosage Gem and Cis (NGC), as an alternative formulation for lung cancer treatment. NGC was prepared using a very simple heating method and was further optimized by D-optimal mixture design. The optimum NGC formulation with particle size, polydispersity index (PDI), and zeta potential of 166.45 nm, 0.16, and −15.28 mV, respectively, was obtained and remained stable at 27 °C with no phase separation for up to 90 days. The aerosol output was 96.22%, which indicates its suitability as aerosolized formulation. An in vitro drug release study using the dialysis bag diffusion technique showed controlled release for both drugs up to 24 h penetration. A cytotoxicity study against normal lung (MRC5) and lung cancer (A549) cell lines was investigated. The results showed that the optimized NGC had reduced cytotoxicity effects against both MRC5 and A549 when compared with the control (Gem + Cis alone) from very toxic (IC₅₀ < 1.56 µg/mL) to weakly toxic (IC₅₀ 280.00 µg/mL) and moderately toxic (IC₅₀ = 46.00 µg/mL), respectively, after 72 h of treatment. These findings revealed that the optimized NGC has excellent potential and is a promising prospect in aerosolized delivery systems to treat lung cancer that warrants further investigation.

Development of Optimized, Inhalable, Gemcitabine-Loaded Gelatin Nanocarriers for Lung Cancer

BACKGROUND

Aerosol delivery of chemotherapeutic nanocarriers represents a promising alternative for lung cancer therapy. This study optimized gemcitabine (Gem)-loaded gelatin nanocarriers (GNCs) cross-linked with genipin (Gem-GNCs) to evaluate their potential for nebulized lung cancer treatment.

METHODS

Gem-GNCs were prepared by two-step desolvation and optimized through Taguchi design and characterized for physicochemical properties. Particle size and morphology were confirmed by scanning and transmission electron microscopy. In vitro release of Gem from Gem-GNCs performed in Dulbecco's phosphate-buffered saline and simulated lung fluid was evaluated to determine release mechanisms. Particle size stability was assessed under varying pH. Differential scanning calorimetry and powder X-ray diffraction were used to determine the presence and stability of Gem-GNC components and amorphization of Gem, respectively. Gem-GNC efficacy within A549 and H460 cells was evaluated using MTT assays. Mucus rheology upon treatment with Gem-GNCs, lactose, and normal saline control was measured. Andersen cascade impaction identified the aerodynamic particle size distribution of the nebulized formulation.

RESULTS

Gem-GNCs had particle size, zeta potential, entrapment efficiency, and loading efficiency of 178 ± 7.1 nm, -18.9 mV, 92.5%, and 9.1%, respectively. The Gem and formulation excipients where molecularly dispersed and configured amorphously. Gem-GNCs were stable at pH 5.4-7.4 for 72 hours. Gem release from Gem-GNCs was governed by non-Fickian controlled release due to diffusion/erosion from a matrix-based nanocarrier. Gem-GNCs elicited a 40% reduction of the complex viscosity η*(1 Hz) of human bronchial epithelial cell mucus containing 3 wt% solids to mimic mild airway disease. The nebulized Gem-GNCs had a mass median aerodynamic diameter (MMAD) of 2.0 ± 0.16 μm, geometric standard deviation (GSD) of 2.7 ± 0.16, and fine particle fraction (FPF) of 75.2% ± 2.4%. The Gem-GNC formulation did not outperform the Gem solution in A549 cells. However, in H460, Gem-GNCs outperformed the Gem IC50 reduction by ∼5-fold at 48 and 10-fold 72 hours.

CONCLUSION

Stable, effective, and sustained-release Gem-GNCs were developed. The nebulized Gem-GNCs had satisfactory MMAD, GSD, and FPF and the formulation reduced the dynamic complex viscosity of mucus consistent with increased mobility of nanoparticles.

Variability of breath condensate pH may contribute to the better understanding of non-allergic seasonal respiratory diseases

The seasonal variability of certain non-allergic respiratory diseases is not clearly understood. Analysis of the breath condensate, the liquid that can be collected by breathing into a cold tube, has been proposed to bring closer to the understanding of airway pathologies. It has been assumed, that (1) airway lining fluid was a stable body liquid and (2) the breath condensate samples were representative of the airway lining fluid. Research was focussed on the identification of biomarkers indicative of respiratory pathologies. Despite 30 years of extended investigations breath condensate analysis has not gained any clinical implementation so far. The pH of the condensate is the characteristic that can be determined with the highest reproducibility. The present paper shows, that contrary to the initial assumptions, breath condensate is not a representative of the airway lining fluid, and the airway lining fluid is not a stable body liquid. Condensate pH shows baseline variability and it is influenced by drinking and by the ambient temperature. The changes in condensate pH are linked to changes in airway lining fluid pH. The variability of airway lining fluid pH may explain seasonal incidence of certain non-allergic respiratory diseases such as the catching of a common cold and the increased incidence of COPD exacerbations and exercise-induced bronchoconstriction in cold periods.

Detection of cancer embryo antigen and endothelin-1 in exhaled breath condensate: A novel approach to investigate non-small cell lung cancer

The present study aimed to investigate the clinical significance of cancer embryo antigen (CEA) and endothelin-1 (ET-1) in the exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC). EBC samples were collected from 143 patients with NSCLC and 119 healthy individuals by using an EBC collector. The CEA and ET-1 levels in the EBC and serum were detected. The levels of CEA and ET-1 in the serum and EBC of the NSCLC group were higher compared with those of the healthy group. The level of CEA in the EBC of the adenocarcinoma group was higher compared with that in the squamous cell carcinoma group. The levels of CEA and ET-1 in the serum and EBC in stages III and IV were higher compared with those in stages I and II. The levels of CEA and ET-1 in the EBC were positively correlated with those in the serum, and furthermore, they exhibited high specificity and sensitivity. Thus, these parameters may be used to diagnose lung cancer. The detection of CEA and ET-1 in EBC may help the process of diagnosing and monitoring the progression of NSCLC.

The effects of lung recruitment maneuvers on exhaled breath condensate pH

Exhaled breath condensate (EBC) pH serves as a surrogate marker of airway lining fluid (ALF) pH and can be used to evaluate airway acidification (AA). AA is known to be present in acute respiratory distress syndrome (ARDS) and can be evaluated via continuous EBC pH measurement during mechanical ventilation. Lung recruitment maneuvers (LRMs) are utilized in the treatment of ARDS, however, their impact on EBC pH has never been explored. Here we described the acute effects of two commonly used LRMs on EBC pH. In a prospective, non-randomized, serial exposure study, 10 intubated pediatric subjects with acute respiratory distress syndrome sequentially underwent: a period of baseline ventilation, sustained inflation (SI) maneuver of 40 cm H2O for 40 s, open lung ventilation, staircase recruitment strategy (SRS) (which involves a systematic ramping of plateau pressures in 5 cm H2O increments, starting at 30 cm H2O), and PEEP titration. Maximum lung recruitment during the SRS is defined as a PaO2 + PaCO2 of  >400 mmHg. Following lung recruitment, PEEP titration was conducted from 20 cm H2O in 2 cm H2O decrements until a PaO2 + PaCO2 was  <380 and then increased by 2 cm H2O. EBC pH, arterial blood gases, lung mechanics, hemodynamics, and function residual capacity were obtained following each phase of the LRM and observational period. Seven out of 10 patients were able to reach maximum lung recruitment. Baseline EBC pH (6.38   ±   0.37) did not correlate with disease severity defined by PaO2/FiO2 ratio or oxygenation index (OI). Average EBC pH differed between phases and decreased after LRM (p = 0.001). EBC pH is affected by LRMs. EBC acidification following LRMs may represent a washout effect of opening acidic lung units and ventilating them or acute AA resulting from LRM.

Exhaled Breath Condensate pH in Lung Cancer, the Impact of Clinical Factors

PURPOSE

Lung cancer may be associated with airway acidification due to enhanced airway inflammation and oxidative stress. Exhaled breath condensate (EBC) pH is a non-invasive indicator of airway acidity; however, it is still unclear how EBC pH changes in lung cancer. The aim of the study was to investigate EBC pH in lung cancer together with clinical variables.

METHODS

Thirty-five patients with lung cancer and 37 control subjects (21 patients with stable COPD and 16 non-COPD smokers) were enrolled. EBC was collected for pH, which was determined with the argon-purging method, compared among the groups and correlated with clinical variables of patients with lung cancer.

RESULTS

No difference was found in EBC pH between patients with lung cancer and control subjects. However, endobronchial tumour localisation, squamous-cell carcinoma subtype and gastro-oesophageal reflux were associated with low EBC pH values. No relationship was observed between EBC pH and the presence of COPD, lung function variables or smoking history.

CONCLUSIONS

Although, EBC pH is unchanged in lung cancer, lower EBC pH values are associated with distinct phenotypes. Our findings could facilitate further research on airway acidity in lung cancer.

Biomarkers in Exhaled Breath Condensate and Serum of Chronic Obstructive Pulmonary Disease and Non-Small-Cell Lung Cancer

Chronic obstructive pulmonary disease (COPD) and lung cancer are leading causes of deaths worldwide which are associated with chronic inflammation and oxidative stress. Lung cancer, in particular, has a very high mortality rate due to the characteristically late diagnosis. As such, identification of novel biomarkers which allow for early diagnosis of these diseases could improve outcome and survival rate. Markers of oxidative stress in exhaled breath condensate (EBC) are examples of potential diagnostic markers for both COPD and non-small-cell lung cancer (NSCLC). They may even be useful in monitoring treatment response. In the serum, S100A8, S100A9, and S100A12 of the S100 proteins are proinflammatory markers. They have been indicated in several inflammatory diseases and cancers including secondary metastasis into the lung. It is highly likely that they not only have the potential to be diagnostic biomarkers for NSCLC but also prognostic indicators and therapeutic targets.

Assessment of airway inflammation in chronic obstructive pulmonary disease: Biomarkers in exhaled breath condensate

Airway inflammation plays a central role in the pathophysiology of chronic obstructive pulmonary disease. Exposure to cigarette smoke induces the recruitment of inflammatory cells in the airways, which in turn produces various cytokines, chemokines, proteases and pro-inflammatory mediators leading ultimately to increased oxidative stress, a protease/anti-protease imbalance and progressive lung tissue injury. Biomarkers may be useful in monitoring airway inflammation and oxidative stress, defining different phenotypes of the disease and evaluating the response of therapies. Exhaled breath condensate collection is a simple and completely non-invasive method of sampling the lower respiratory tract in humans. Exhaled breath condensate may be a rich source of pulmonary biomarkers including hydrogen peroxide, cytokines, metabolites of the arachidonic acid, nitric oxides and the pH. However, the concentration of these biomarkers is often very low, which may cause several problems in their detection. The clinical applicability of exhaled breath condensate biomarkers cannot be assessed until methods of sample collection and analysis have been standardized. Orv. Hetil., 2012, 153, 843–851.