Nanoparticles:: Characteristics, mechanisms of action, and toxicity in pulmonary drug delivery -: A review

The pulmonary route has recently gained momentum as a suitable avenue for drug delivery. The large alveolar surface area of approximately 75 m(2) coupled with the thin epithelial barrier and extensive vascularization all might enhance drug transport and uptake. Such an avenue for drug delivery would greatly facilitate the treatment of pulmonary diseases such as tuberculosis and cystic fibrosis. With direct delivery of therapeutic agents to the desired site of action, systemic side-effects might be reduced. The discipline known as nanomedicine has a vast potential for therapeutic treatment of diseases through targeted drug delivery. The manipulation of particle characteristics including size, surface chemistry, surface charge, and surface area, allows for the possibility of synthesizing particles specific for targeting to various cellular populations and organs including systems such as the respiratory tract. Specifically, pulmonary drug delivery is an area currently being extensively investigated through the use of nanoparticles (particles that have a mean diameter of 300 nm or less) and it is anticipated that in the near future pulmonary diseases may be treated effectively and efficiently using inhalable therapeutic agents loaded nanoparticles. Such an approach might reduce drug related systemic side effects. Subsequent to the use of nanoparticles as a favourable avenue for drug delivery consideration must be given towards their toxicological properties. Upon identification of the various modes of interaction it will be possible to control and minimize such detrimental effects allowing for nanoparticles to be safely utilized as therapeutic agents for site-specific drug delivery.