Patent ID: 8802154

Claim:
A method of localizing thermal damage to a pilosebaceous unit, comprising: providing a composition comprising a plurality of unassembled plasmonic nanoparticles and a cosmetically acceptable carrier configured for topical administration to a skin surface, wherein the plurality of unassembled plasmonic nanoparticles are not bound to each other through a physical force or chemical bond either directly or indirectly through an intermediary, wherein the unassembled plasmonic nanoparticles comprise a conductive metal portion, wherein the unassembled plasmonic nanoparticles have a size in a range of 10 nm to 300 nm, wherein the unassembled plasmonic nanoparticles comprise a coating that coats the conductive metal portion, wherein said coating facilitates selective removal from the skin surface; wherein the coating is less conductive than the conductive metal portion, wherein the coating comprises silica or polyethylene glycol (PEG), wherein the conductive metal portion and the coating form a metal/dielectric interface, wherein the conductive metal portion comprises at least one of gold or silver, wherein the unassembled plasmonic nanoparticles have a concentration of 10 9 to 10 23 particles per ml of a solution in the composition, wherein said concentration of the unassembled plasmonic nanoparticles is sufficient to, after exposure to irradiation and activation of a surface plasmon, induce thermal damage in the pilosebaceous unit; topically applying the composition to the skin surface; targeting the pilosebaceous unit by redistributing the composition from the skin surface to a portion of the pilosebaceous unit; wherein the portion of the pilosebaceous unit comprises one or more structures consisting of: a hair shaft, a hair follicle, a sebaceous gland, an arrector pili muscle, sebum, and a hair follicle infundibulum; selectively removing the composition from the skin surface, while leaving the composition localized within the pilosebaceous unit; and irradiating the composition with an infrared light source in a range of 750 nm to 1200 nm thereby inducing the surface plasmon in said unassembled plasmonic nanoparticles, wherein the surface plasmon comprises an electromagnetic wave at the metal/dielectric interface, thereby inducing heat radiation from the unassembled plasmonic nanoparticle, thereby localizing thermal damage to said pilosebaceous unit.