Nanoparticles, bits of material smaller than cells, are a promising way to deliver drugs, but they have to get past the immune system fist.
A recent study from the Methodist Hospital System Research Institute in Houston demonstrated sending in particles disguised as white blood cells could sneak them past the immune cells until they are needed.
Led by Ennio Tascioti, co-chairman of the department of nanomedicine at the institute, scientists were able to harvest the cell membranes from leukocytes, or white blood cells. The membranes attached themselves to tiny particles of silicon. Because the silicon now looks like a white cell, it gets ignored by the rest of the immune system.
Leukocyte membranes can target certain kinds of cells. In the immune system, different kinds of leukocytes attack bacteria, or stimulate the release of histamine, which is what makes people sneeze when they are allergic to cats or pollen. By covering the nanoparticle in a certain kind of white blood cell membrane, it's possible to target specific tissues precisely.
This was shown in tumor cells in mice. The ability to evade the immune system allowed the nanoparticles to concentrate on the tumor before the body's own protective systems stopped them.
The research was published in the Dec. 16 issue of the journal Nature Nanotechnology.