Investigators at Beth Israel Deaconess Medical Center and the Harvard School of Public Health have been using a locally developed system to track near-infrared fluorescent nanoparticles as they enter and leave the lungs. The FLARE system (fluorescence-assisted resection and exploration), which we originally covered two years ago, may become a clinical modality for initial diagnosis and follow up after tumor resection, as well as an investigational tool to understand how different compounds affect the lungs.
The aim of this new study was to determine the characteristics and parameters of inhaled nanoparticles that mediate their uptake into the body — from the external environment, across the alveolar lung surface and into the lymphatic system and blood stream and eventually to other organs. To do this, the scientists made use of the fluorescence-assisted resection and exploration (FLARE) imaging system, systematically varying the chemical composition, size, shape, and surface charge of a group of near-infrared fluorescent nanoparticles to compare the physiochemical properties of the various engineered particles. The investigators then tracked the movement of the varying nanoparticles in the lungs of rat models over a period of an hour, and also verified results using conventional radioactive tracers.
The results established that nonpositively charged nanoparticles, smaller than 34 nm in diameter, appeared in the lung-draining lymph nodes within 30 minutes. They also found that nanoparticles smaller than 6 nm in diameter with "zwitterionic" characteristics (equal positive and negative charge) traveled to the draining lymph nodes within just a few minutes, subsequently being cleared by the kidneys into urine.
Full story: Tracking nanoparticles could help in developing treatment for pulmonary disease …
Abstract in Nature Biotechnology: Rapid translocation of nanoparticles from the lung airspaces to the body
Flashback: FLARE Lights Up Tumors
