Deposition and Clinical Impact of Inhaled Particles in the Lung

Particles suspended in the air we breathe are deposited in the airways as a function of the properties of the particle itself (shape, size and hydration), inspiratory air flow, airway anatomy, breathing environment, and mucociliary clearance. The scientific study of the deposition of inhaled particles in the airways has been conducted using traditional mathematical models and imaging techniques with particle markers. In recent years, the integration of statistical and computer methods, giving rise to a new discipline called digital microfluidics, has led to significant advances. In routine clinical practice, these studies are of great use for optimizing inhaler devices in line with particular characteristics of the drug to be inhaled and the pathology of the patient. (AU)

Deposition and Clinical Impact of Inhaled Particles in the Lung.

Particles suspended in the air we breathe are deposited in the airways as a function of the properties of the particle itself (shape, size and hydration), inspiratory air flow, airway anatomy, breathing environment, and mucociliary clearance. The scientific study of the deposition of inhaled particles in the airways has been conducted using traditional mathematical models and imaging techniques with particle markers. In recent years, the integration of statistical and computer methods, giving rise to a new discipline called digital microfluidics, has led to significant advances. In routine clinical practice, these studies are of great use for optimizing inhaler devices in line with particular characteristics of the drug to be inhaled and the pathology of the patient.

An Update on Advancements and Challenges in Inhalational Drug Delivery for Pulmonary Arterial Hypertension.

A lethal condition at the arterial-alveolar juncture caused the exhaustive remodeling of pulmonary arterioles and persistent vasoconstriction, followed by a cumulative augmentation of resistance at the pulmonary vascular and, consequently, right-heart collapse. The selective dilation of the pulmonary endothelium and remodeled vasculature can be achieved by using targeted drug delivery in PAH. Although 12 therapeutics were approved by the FDA for PAH, because of traditional non-specific targeting, they suffered from inconsistent drug release. Despite available inhalation delivery platforms, drug particle deposition into the microenvironment of the pulmonary vasculature and the consequent efficacy of molecules are influenced by pathophysiological conditions, the characteristics of aerosolized mist, and formulations. Uncertainty exists in peripheral hemodynamics outside the pulmonary vasculature and extra-pulmonary side effects, which may be further exacerbated by underlying disease states. The speedy improvement of arterial pressure is possible via the inhalation route because it has direct access to pulmonary arterioles. Additionally, closed particle deposition and accumulation in diseased tissues benefit the restoration of remolded arterioles by reducing fallacious drug deposition in other organs. This review is designed to decipher the pathological changes that should be taken into account when targeting the underlying pulmonary endothelial vasculature, especially with regard to inhaled particle deposition in the alveolar vasculature and characteristic formulations.

Phytobarriers: Plants capture particles containing potentially toxic elements originating from mine tailings in semiarid regions.

Retention of particles containing potentially toxic elements (PTEs) on plants that spontaneously colonize mine tailings was studied through comparison of washed and unwashed shoot samples. Zn, Pb, Cd, Cu, Ni, Co and Mn concentrations were determined in plant samples. Particles retained on leaves were examined by Scanning Electronic Microscopy and energy dispersive X-Ray analysis. Particles containing PTEs were detected on both washed and unwashed leaves. This indicates that the thorough washing procedure did not remove all the particles containing PTEs from the leaf surface, leading to an overestimation of the concentrations of PTEs in plant tissues. Particularly trichomes and fungal mycelium were retaining particles. The quantity and composition of particles varied among plant species and place of collection. It is obvious that plants growing on toxic mine tailings form a physical barrier against particle dispersion and hence limit the spread of PTEs by wind.