The significance of nanoparticles in medicine and their potential application in asthma

In an attempt to diagnose and treat highly complex and often heterogeneous diseases, research aims to utilise the modifiable properties of nano-sized particles. Properties such as size, shape, charge, hydrophobicity, and surface chemistry may be altered in order to facilitate and promote targeted cellular uptake. Following the first FDA-approved nanotherapeutic in 1990, more than 40 have been marketed worldwide with multiple nano-based medicines currently in development. Despite promising results, translation from pre-clinical experimentation to a clinical setting has proven to be difficult. In theory, nanoparticles are designed to possess characteristics which address many of the challenges associated with current clinical practices, such as low toxicity, stability, biocompatibility, favourable distribution within target tissue, and beneficial pharmacokinetic profiles. However, the complexity in the identification of the ideal properties which result in such characteristics is inherent of any therapeutic research, especially one as novel and relatively progressive. The development of nanoparticles for localised and systemic delivery to the lung in the treatment of respiratory disease also shows great potential. Due to the highly efficient clearance mechanisms in the lung, the ability for therapeutics to successfully deposit in the respiratory tract is a major challenge. Yet a correlation between exposure to environmentally and occupationally derived ultrafine (nano-sized) particles and respiratory disease has been established. By confirming that ultrafine particles have the capacity to deposit in parts of the lower respiratory tract to elicit a response albeit toxic, such epidemiological studies provide rationale for the development of nano-based pulmonary therapeutics. Although there has been little effort in designing nanoparticle systems for the treatment of lung disease including asthma, current research involves the development of nanocarriers for clinically relevant asthma drugs and antigen (for immunotherapy). With this, continued advancements in the understanding of human disease including asthma, coupled with knowledge regarding interactions between nanoparticle and cell/tissue systems, are required and provide the platform for nano-based therapeutic and diagnostic research.