Research published this week in the online early edition of the Proceedings of the National Academy of Sciences will enable scientists to simulate the pathway of drug treatments with inhalers in a poorly understood area of the lung.
The airways of all mammals include an area known as the pulmonary acinus, which looks like a bunch of grapes attached to a stem (acinus means “berry” in Latin). Scientists have struggled to understand what exactly happens in this microscopic, maze-like area of the lung system.
A research team led by the University of Iowa in the USA has created a detailed, three-dimensional rendering of the pulmonary acinus. The computerised model developed from mice, which have a very similar respiratory system to humans, is an accurate model of every twist and turn in this region, including the length, direction and angles of the respiratory branches that lead to the air sacs called alveoli.The model is important, because it can help scientists understand where and how lung diseases emerge as well as the role the pulmonary acinus plays in the delivery of drugs, such as those commonly administered with inhalers.
“These methods allow us to understand where in the lung periphery disease begins and how it progresses,” says Eric Hoffman, professor in the departments of radiology, medicine and biomedical engineering at the University of Iowa and co-author on the paper. “How do gases and inhaled substances get there and do they accumulate in one or another acinus? How do they swirl around and clear out? We just don’t have a complete understanding how that happens.”
Hoffman and Dragos Vasilescu, first author of the research paper, say that the model could be used to determine how smoking-induced chronic obstructive pulmonary disease originates and improve understanding of the region leading to more effective treatment of chronic obstructive pulmonary disease.
Previous models could replicate the structure of the lung in real life but could not convey how various parts act together as a whole. Advances in imaging and computation have enabled researchers to more fully explore how gases and other inhaled substances act in areas of the lung that were previously too complex to model.
The researchers’ next aim is to use the model to more fully understand how gases interact with the bloodstream within the acini and the alveoli.