Controlled pulmonary drug and gene delivery using polymeric nano-carriers.

Pulmonary drug and gene delivery to the lung represents a non-invasive avenue for local and systemic therapies. However, the respiratory tract provides substantial barriers that need to be overcome for successful pulmonary application. In this regard, micro- and nano-sized particles offer novel concepts for the development of optimized therapeutic tools in pulmonary research. Polymeric nano-carriers are generally preferred as controlled pulmonary delivery systems due to prolonged retention in the lung. Specific manipulation of nano-carrier characteristics enables the design of "intelligent" carriers specific for modulation of the duration and intensity of pharmacological effects. New formulations should be tested for pulmonary absorption and distribution using more advanced ex vivo and in vivo models. The delivery of nano-carriers to the air-space enables a detailed characterization of the interaction between the carrier vehicle and the natural pulmonary environment. In summary, polymeric nanoparticles seem to be especially promising as controlled delivery systems and represent a solid basis for future advancement for pulmonary delivery applications.