Abstract: The invention provides methods and apparatus for stable generation and delivery of solid nano-particles in aerosols that simultaneously maintain high nano-particle concentration, and which avoid coagulation and agglomeration of the nano-particles. The apparatus includes a Collison nebulizer is in communication with a plenum. The Collison nebulizer includes a port for introducing a helium gas flow into the Collison nebulizer. The plenum includes component(s) for providing flow of uniform axially symmetrical dry air around the nano-particles entrained in the helium gas flow in the plenum. Preferably, the plenum includes an uniformity screen and a reduction in the plenum circumference downstream from the uniformity screen. In some preferred aspects, the invention provides methods of introducing nanoparticles into the lungs of test animals. The present invention allows more than 0.5 mass % of the nano-particles to be deposited in an animal's lungs.

Abstract: The invention provides methods and apparatus for stable generation and delivery of solid nano-particles in aerosols that simultaneously maintain high nano-particle concentration, and which avoid coagulation and agglomeration of the nano-particles. The apparatus includes a Collison nebulizer is in communication with a plenum. The Collison nebulizer includes a port for introducing a helium gas flow into the Collison nebulizer. The plenum includes component(s) for providing flow of uniform axially symmetrical dry air around the nano-particles entrained in the helium gas flow in the plenum. Preferably, the plenum includes an uniformity screen and a reduction in the plenum circumference downstream from the uniformity screen. In some preferred aspects, the invention provides methods of introducing nanoparticles into the lungs of test animals. The present invention allows more than 0.5 mass % of the nano-particles to be deposited in an animal's lungs.