Targeted Drug Delivery Systems for Lung Macrophages.

Lung macrophages present an effective role in innate and immune response through specific and non-specific mechanisms, namely phagocytosis, antigen processing and presentation through major histocompatibility complex, activation of T cells and inflammatory cytokines release. Despite their protective role against injury in normal condition, they can cause several lung conditions, since they can mediate several processes, through recruitment of other inflammatory cells for alveolar space, release of proinflammatory cytokines or stimulation of collagen deposition. Lung macrophages constitute a good therapeutic target. With the development of nanotechnology, new carriers have been designed to target drugs towards these cells. One of the commonly used approaches is the attachment of ligands with affinity to receptors presented at lung macrophage surface, to the nanocarriers. This review will focus on the importance of lung macrophages in host-defense, their influence on different pulmonary diseases and different strategies for alveolar macrophage targeting.