Pulmonary drug delivery alveolar cells

Elbert KJ, Schafer UF, Schafers HJ, Kim KJ, Lee VHL, Lehr C-M (1999) Mono-layers of human alveolar epithelial cells in primary cultures for pulmonary drug delivery and transport studies. Pharm Res 16 601-608. 

An ideal in vitro model for the characterization of aerosol formulations would incorporate cell types from various regions of the lung (tracheal, bronchial, and alveolar) and would facilitate simulation of deposition mechanisms by impaction, sedimentation, and diffusion of a high-metered singlebolus inhalation. In the future, such systems may reduce the need for animal studies and may offer to correlate in a predictive way the results from such in vitro tests to clinical bioavailability data after pulmonary drug delivery in vivo. 

The lung comprises about 40 different cell types, amongst which type I and type II alveolar epithelial cells are the major types targeted by pulmonary drug delivery systems. Type I cells play an important role in the absorption process of proteins, while type II cells produce surfactant, regulate the immune response, and serve... 

Pulmonary drug delivery is also applicable using liposomes, because they are absorbed through the thin layer of alveolar epithelial cells (vast surface for an adult is 43-102 m ) (12-14) and transported into the systemic circulation (15-17). However, the inhaled objects can be eliminated by macrophages from the alveoli surface when they are bigger than 260 nm (18). 

Brack A, Abu-Dahab R, Borchard G, et al. Lectin-functionalized liposomes for pulmonary drug delivery interaction with human alveolar epithelial cells. J Drug Target 2001 9 241. 

---