Scientists have tracked the flow of nanoparticles from the lungs to the bloodstream for the first time. The work could lead to the development of new drugs and help researchers understand how pollution can cause respiratory problems

Researchers from Beth Israel Deaconess Medical Center and the Harvard School of Public Health injected fluorescent nanoparticles into rats’ lungs and used near-infrared imaging to watch as the particles moved through their bodies. The researchers tracked how far—and how quickly—nanoparticles of different size, shape, and surface charge were able to travel after being injected. They found that nanoparticles between six and 34 nanometers in diameter were able to get past the lung’s defenses to reach the lymph nodes and the bloodstream. This finding may provide valuable guidelines for designing nanoparticle-based drugs.

What Happens When You Breathe In Nanoparticles – Technology Review.