Drag-minimizing spore/pollen-mimicking microparticles for enhanced pulmonary drug delivery: CFD and experimental studies

The aim of this work is to build a Computational fluid dynamics (CFD) model to study the flowability of fungal spores and pollen grains to predict their ability to flow to the deep lung in order to relate this to the potentiality of allergies, and predict the possibility of using spores/pollen grains-mimicking microparticles for pulmonary drug delivery. The CFD model was designed using COMSOL Multiphysics to calculate the drag forces exerted on the pollens and spores by the air in the upper and lower lung bronchioles. Experimental verification was conducted by comparing the aerosolization of Aspergillus spores and spherical microparticles, as a control shape, using Next Generation Impactor as a lung-simulation device. The CFD model showed that the drag force exerted on the spores and pollen grains can affect their pathogenicity. In addition, the shapes of some spores (e.g. Alternaria, Drechslera and Aspergillus) or pollens (e.g. Quercus and Eucalyptus) have low drag and can be used for drug delivery to the deep lung. The experimental results coincided with the CFD model and showed that the shape of Aspergillus spores can reach the deep lung with about 1.6-fold higher dose than the spherical shape. The obtained results indicate that shapes of some spores and pollen grains are drag-minimizing allowing them to spread and to be inhaled to the deep lung; so they can be used for the development of dry powder inhaler formulations.

Automated summary

The aim of this work is to build a computational model to study the flowability of fungal spores and pollen grains in order to predict their ability to reach the deep lung and relate it to allergies. The results show that the drag force exerted on the spores and pollen grains can affect their ability to cause disease. Additionally, certain shapes of spores and pollen grains have low drag and can be used for drug delivery to the deep lung.