"One gram of this kind of material can have a total surface area of a football field, making it possible to carry a large payload," Trewyn said.
Lin’s nanoparticle has a unique "capping" strategy that seals the chemical goods inside. In previous studies, his group successfully demonstrated that the caps can be chemically activated to pop open and release the cargo inside of animal cells. This unique feature provides total control for timing the delivery
The team’s first attempt to use the porous silica nanoparticle to deliver DNA through the rigid wall of the plant cell was unsuccessful. The technology had worked more readily in animals cells because they don’t have walls. The nanoparticles can enter animal cells through a process called endocytosis ?the cell swallows or engulfs a molecule that is outside of it. The biologists attempted to mimic that process by removing the wall of the plant cell (called making protoplasts), forcing it to behave like an animal cell and swallow the nanoparticle. It didn’t work.
They decided instead to modify the surface of the particle with a chemical coating.
"The team found a chemical we could use that made the nanoparticle look yummy to the plant cells so they would swallow the particles," Torney said.
It worked. The nanoparticles were swallowed by the plant protoplasts, which are a type of spherical plant cells without cell walls.
Most plant transformation, however, occurs with the use of a gene gun, not through endocytosis. In order to use the gene gun to introduce the nanoparticles to walled plant cells, the chemists made another clever modification on the particle surface. They synthesized even smaller gold particles to cap the nanoparticles. These "golden g
Source:Iowa State University