Patent attributes
An expandable medical device having a particle layer disposed over a reservoir containing a therapeutic agent. The particle layer has a first porosity when the medical device is in the unexpanded configuration and a second porosity when the medical device is in the expanded configuration. The particle layer comprises a plurality of micron-sized or nano-sized particles. In certain embodiments, the particles are not connected to each other, and as such, the different porosities are provided by changes in the spacing between the particles as the medical device is expanded/unexpanded. Also disclosed are medical devices having a particle layer, wherein the particle layer comprises a plurality of encapsulated particles, and methods of coating medical devices with particles.