Richard Liang 18’

Mucoadhesive particles (MAPs) are used as the primary method of pulmonary drug delivery since it was believed that they increase drug duration within the lungs. MAPs act by sticking to the mucus layers and are used to treat a variety of illnesses including asthma, cystic fibrosis and lung cancer. However, administered MAPs are, in reality, quickly removed from the body via physiologic mucus clearance mechanisms and are considered not efficient. In a recent study lead by Craig S. Schneider from the Center for Nanomedicine in the John Hopkins University School of Medicine, an alternative pulmonary drug delivery method was developed to overcome the flaws of MAPs.

Developing mucus-penetrating particles (MPPs) was proposed as an alternative strategy for pulmonary drug delivery. These are particles with diameters much smaller than the mucus mesh spacing; able to rapidly penetrate mucus layers rather than stick to them. Trials were done by administering dexamethasone sodium phosphate using MAPs and MPPs of various diameters to mice with acute lung inflammation. Four diameters were used: 60 nm, 100 nm, 300 nm, and 1000 nm.

According to the results, when the diameters of the particles were equal to or less than 300nm, the retained MPPs were twice as great the amount of retained MAPs. When the MPPs and MAPs had diameters of 1000 nm showed no significant differences in retention. Using a Xenogen IVIS Spectrum live animal imaging system, the MPPs were found to be more uniformly distributed throughout the lungs, compared to the MAPs. This supports the hypothesis that MPPs may be a more effective pulmonary drug delivery system than MAPs, with the potential to treat respiratory diseases more effectively. Further research involving clinical trials should be undertaken, in order to observe efficacy and side effects in humans.

References

1. C. S. Schneider, et al., Nanoparticles that do not adhere to mucus provide uniform and long-lasting drug delivery to airways following inhalation. Science Advances 3, (2017) e1601556 DOI: 10.1126/sciadv.1601556
2. Image retrieved from: https://c1.staticflickr.com/7/6136/5950870440_d308714ee0_z.jpg