Nanoparticles help in predicting COPD progression when their movement is disturbed by the mucus lining structure in the airway.
FREMONT, CA: Chronic obstructive pulmonary disease (COPD) puts one’s health at risk leading to severe complications as the condition is impossible to cure. According to the World Health Organization, COPD is the fifth leading cause of death worldwide. Management of COPD profoundly suffers from a lack of effective therapies as well as reduced ability to track the disease progression. However, a spirometer can be used to diagnose COPD and other conditions that affect breathing and also periodically monitor the lung condition for the treatments given. But it cannot track the progression of a disease, although it is a “gold standard” technique to diagnose COPD.
Researchers at John Hopkins University have now used microscopic human-made particles to identify the severity of COPD in patients by measuring how quickly the particles move through mucus. Mucus, the slimy lubricant secreted by tissues, is lining the airways that sweep away potentially harmful particles inhaled during breathing and has a structure similar to that of water-filled sponge having many tiny interconnected pores. Scientists have already engineered nanoparticles that do not stick to mucus and are called “muco-inert” particles that can navigate through the maze of mucus pores covering the airways. These nano-sized particles are excellent biomarkers for COPD progression.
The “muco-inert” particles travel slowly inside the mucus as the mucus structure hinders it, and thus, the size of the pore gives an indirect measure of the speed of particles. This, in turn, gives the information about the mucus structure that is distinct for COPD patients affecting the way foreign particles or other pathogens move. To determine this, scientists used mucus samples of 33 patients who were active or former smokes. The patients selected for studies include seven with no history of COPD, 18 with mild to moderate COPD, and 8 with severe COPD as determined by the lung function.
To test the progress of the disease, researchers added nanoparticles labeled with a fluorescent marker that can be traced easily by an ultrasensitive camera into the mucus and observed their speed of movement at which the nanoparticles diffused. From the studies conducted, mucus of COPD patients restricted the movement of the nanoparticles, as compared to the patients without COPD. Consequently, patients with severe COPD showed more obstruction to the flow of particles. Thus, the pore size shrinks with the progression of COPD. In the future, the structure of mucus will be a predictor of COPD progression while providing new insight and help in improving therapy.