Upon reaching airway cells, viruses trigger an inflammatory response in the body. They are recognized by the immune system, which begins releasing cytokines and chemokines – signaling proteins responsible for recruiting defense cells to the infection site. This process worsens inflammation and stimulates excessive mucus production.
The excessive buildup of mucus hinders the defense provided by ciliary movement, making it harder to eliminate the invading agent. The result of viral infection includes symptoms such as fever, cough, respiratory difficulty, or shortness of breath. In more severe cases, inflammation can reach such intense levels that it compromises vital functions and leads to death.
According to the researcher, this modus operandi is common to all major respiratory viruses, such as the flu virus (influenza), respiratory syncytial virus (a common cause of respiratory infections, especially in children and the elderly), and coronaviruses. During the covid-19 pandemic, this mechanism became evident and had a profound impact on public health – the disease caused the death of over 716,000 people in Brazil, according to data from the Ministry of Health.
Considering the inflammation process caused by respiratory viruses, the nanoparticle platform with bromhexine has a second goal: to control excessive inflammation caused by lung infections. In tests conducted, treatment of cells infected by SARS-CoV-2 with the nanoparticles significantly reduced inflammation and increased production of a glycoprotein called MUC1, which is present on the surface of lung cells and plays a natural protective role against inflammation.
The new nanotechnology platform not only crosses the mucus barrier in the lungs but also helps modulate the immune system’s response to infection. For researcher Yugo Martins, this is a new and promising strategy to treat respiratory diseases involving inflammation and excess mucus.
The results were obtained in tests with human respiratory epithelial cells infected with the covid-19 virus. These cells were cultivated in the lab to replicate real conditions of the respiratory system. “We created an environment where the top of the cells is in contact with air and the bottom immersed in a nutrient liquid,” says the researcher, noting that this method allows the cells to develop similarly to how they do in the human body, producing mucus on their surface. “The tests more faithfully simulate the reality of the human respiratory tract,” he adds.
