Making organs transparent to improve nanomedicine

Scientists are trying to design nanoparticles that deliver a therapeutic cargo directly to a disease site. This specific targeting could help avoid the nasty side effects that patients feel when a drug goes to heathy areas in the body. But barriers, such as blood vessel walls, can divert particles from reaching their intended destination. To get around such obstacles, scientists need a better understanding of how nanoparticles interact with structures inside the body. Current techniques, however, are limited. Warren C. W. Chan and colleagues wanted to develop a method to better track where nanoparticles go within tissues.

The researchers injected an acrylamide hydrogel into organs and tissues removed from mice. The gel linked all of the molecules together, except for the lipids, which are responsible for making tissues appear opaque. The lipids easily washed away, leaving the tissues clear but otherwise intact. Using this technique, the researchers could image nanoparticles at a depth of more than 1 millimeter, which is 25 times deeper than existing methods. In addition to helping scientists understand how nanoparticles interact with tumors and organs, the new approach could also contribute to tissue engineering, implant and biosensor applications, say the researchers.