Companies typically file patent applications to protect their products and their market share. For this reason, patents and published patent applications may provide a good indicator of the commercialization trends in nanotechnology. Based on patent applications published by the U.S. Patent Office over the last five years, the hottest trends in nanotechnology commercialization are in nanoparticles, nanotubes, nanowires, quantum dots, and nanofilms. The most popular patent applications for nanoparticles relate to drug delivery, fluorescent devices, and ultra violet light applications. The most popular patent applications for nanotubes relate to conductivity and catalyst applications.