New inhalation drug shows promise in preventing lung infections

A new study explores how using a particular medicine breathed in can help stop severe lung infections. These infections, known as pneumonia, can be dangerous and cause breathing problems.

Sometimes, when people get sick with diseases like Covid-19, their immune cells become too active and can damage the lungs. Researchers at the Technical University of Munich (TUM) have created a particular substance that can be put into a spray for the lungs. This substance slows down the overly active immune cells called macrophages. They found a new way to carry this substance to the right place in the lungs using sugar.

This particular substance, made from a genetic material called RNA, could help prevent serious lung infections in the future, like bad pneumonia from diseases like Covid-19. The researchers at TUM made this substance and a new way to deliver it. A company from TUM’s work plans to begin testing this substance on people in early 2024.

The scientists, led by Professor Stefan Engelhardt, created an RNA-based substance called RCS-21. This substance works inside cells to stop a molecule called microRNA 21 from being too active. This molecule is one of the reasons why macrophages become too involved and cause problems in the lungs during serious infections like Covid-19.

In the journal “Nature Communications,” a team of researchers detailed their creation of a medicine named RCS-21 and their innovative method of delivering it via an inhaler to target specific cells called macrophages. These cells act like protectors in the body, cleaning out harmful elements like bacteria and fungi to keep the lungs healthy.

The macrophages identify their targets by recognizing specific sugar molecules on the surface of these harmful agents, a quality that sets them apart. To ensure the medicine reaches the macrophages effectively, the researchers connected it to a sugar molecule called trimannose, a technique previously untried with more complex medication. This novel approach was successfully tested on mice, showing promising results.

Christina Beck, the article’s first author, and Deepak Ramanujam said, “When the drug was administered as a spray, macrophages took up the active ingredient significantly better than without sugar molecules. In contrast, other cell types even outright exclude the molecules.

Researchers tested a medicine called RCS-21 on mice, and it worked well. It lowered something called microRNA 21 by more than half, essential because it’s linked to lung infections. The mice treated with RCS-21 had less inflammation and scarring in their lungs. They also tried RCS-21 on human lung samples infected with the Covid-19 virus, which also stopped the harmful effects there.

The government is helping to fund a study for a new medicine. They are checking if the medication is safe, and if everything goes well, they plan to test it on people in 2024. A special company called RNATICS is in charge of this. They got 7 million euros from the government in 2021 to help make this medicine.

One of the people who started RNATICS, Stefan Engelhardt, thinks this technology could be helpful. They found a way to use this medicine that works well, especially for the lungs. He believes that more medications like this will be developed using similar methods.

Journal Reference:

1. Beck, C., Ramanujam, D., Vaccarello, P. et al. Trimannose-coupled antimiR-21 for macrophage-targeted inhalation treatment of acute inflammatory lung damage. Nature Communication. DOI: 10.1038/s41467-023-40185-1.