A computer model for the simulation of fiber-cell interaction in the alveolar region of the respiratory tract

A mathematical model is presented that describes the health-endangering interaction of fibrous particles deposited in the human alveoli with alveolar fluids, cells, and tissues. As suggested by the theoretical approach, short fibers (diameter: 0.5 mu m, length: 2-10 mu m) are preferably ingested by alveolar macrophages and removed from the alveolar surface 10-15 days after exposure. Long (diameter: 0.5 mu m, length: 10-50 mu m) biopersistent fibers are not effectively cleared from the alveoli due to the repeated process of frustrated phagocytosis. Long biosoluble fibers also undergo a frustrated phagocytosis, with processes of extensive lysis leading to their significant shortening. The decrease in length causes the initiation of those clearance mechanisms that are efficient for short fibers. (C) 2011 Elsevier Ltd. All rights reserved.