The new technology can be used to understand the therapeutic success of inhaled active substances.
Nanoparticles are tiny particles that can penetrate through to distant parts of the body. They are often associated with properties detrimental to health; at the same time, however, approaches are being tested to use certain particles for therapy, for example as inhaled drugs. Researchers working with Dr. Otmar Schmid, research group leader at the Institute of Lung Biology and Disease at the Helmholtz Center in Munich, have now developed a method that allows them to examine the success of a therapy much more thoroughly than in the past. “To date, in preclinical tests the lung had to be examined in segments–that is, tissue section by tissue section–under the microscope,” explains research leader Otmar Schmid. “This is very time-consuming, does not cover the entire lung, and is not quantitative in some respects.” Tissue clearing, a method used to render complete organs transparent by means of chemical processes, was thought to provide better examinations.
“However, this approach has not been very successful for the lungs so far, since the large number of alveoli strongly scatter the light, which means that we do not get any good images,” says Dr. Annette Feuchtinger from the Research Unit Analytical Pathology at the Helmholtz Center in Munich, who was also involved in the study. “Our optimized tissue-clearing method will now allow us to bypass these artifacts. This way, it will be possible to visualize the entire respiratory tract from the trachea to the alveoli without having to stain the tissue. On top of that, for the first time we are able to correct any distortions resulting from tissue clearing, which will allow us to precisely measure the 3D structure of the airways in the entire lung.”
The scientists have already demonstrated the efficiency of their method in their current study: Using fluorescent nanoparticles, they were able to visualize and precisely analyze their distribution in the entire lung through cellular resolution. “For instance, this new method will enable us to optimize the application and retention time of nanomedicine to improve the potential therapeutic success,” explains Otmar Schmid. “This will increase the knowledge gained from preclinical in-vivo models in lung research and improve the development of new active substances for lung diseases.”