Cellular and Non-cellular Barriers to Particle Transport Across the Lungs

Abstract

Compared to the human body’s other outer epithelia, like e.g. the skin and the GI tract, the lungs have the largest surface area. Moreover, the so called “air-blood-barrier” is extremely thin, but also very tight to fulfill its physiological function. This chapter discusses the lung as a biological barrier in the context of inhaled particles. This important function is provided by some specific cellular as well as non-cellular elements. How the lung copes with particles “after landing” is not only relevant regarding the risks of accidentally inhaled nanomaterials, but also for designing safe and efficient nanopharmaceuticals to be inhaled on purpose.