Exploring nanoparticles in lungs under COPD conditions for nanospray drug flow and deposition: CFD simulations and AI...

Chronic obstructive pulmonary disease (COPD) plays a heavy burden on individuals and the social health system, not only causing direct medical costs but also economic losses. Today, treatments for COPD include drugs, bronchodilators, and oxygen therapies. In these treatments, depositing drug particles within the bronchioles is quite critical. This study utilizes the Weibel five-generation lung model (G5-G9) and the out-of-plane modeling method to improve the three-dimensional characterization of the airways. COPD's impact on nanoparticle deposition at different stages is evaluated under the actual respiratory condition with a respiratory rate of about 30 L‧min^-1. In addition, the deposition of medicine nanoparticles at three typical nanoparticle densities (i.e., 1000, 1100, and 1550 kg m^-3) is also studied by considering the nanoparticle sizes ranging from 10 to 100 nm. The predictions illustrate the airflow patterns of streamlines. The characteristics of nanoparticle deposition and the correlations between Stokes number and total deposition are further explored. It is found that COPD significantly affects airflow patterns and causes disturbances at airway bifurcations, which leads to higher flow velocities, more collisions of nanoparticles on the walls, and subsequent nanoparticle deposition. Remarkable hot spots occur in some airway segments due to airflow deflection and secondary flow appearance. Furthermore, the impact of various nanoparticle sizes can be predicted at each stage by employing artificial neural networks based on computational fluid dynamics data of flow patterns and deposition of drug nanoparticles. The results benefit the reduction of drug waste, thereby lowering the escalating global public health burden associated with COPD.