Compositions and methods comprising energy absorbing compounds for follicular delivery

Abstract

The present invention provides compositions comprising energy (e.g., light) absorbing submicron particles (e.g., nanoparticles comprising a silica core and a gold shell) and methods for delivering such particles via topical application. This delivery is facilitated by application of mechanical agitation (e.g. massage), acoustic vibration in the range of 10 Hz-20 kHz, ultrasound, alternating suction and pressure, and microjets.

1 . A method of localizing thermal damage to a pilosebaceous unit, comprising:
 topically applying a solution of unassembled plasmonic nanoparticles to a skin surface,   wherein the plasmonic nanoparticles comprise a conductive metal portion, wherein the conductive metal portion comprises at least one of gold, silver, nickel, platinum, and titanium,   wherein the plasmonic nanoparticles comprise a coating that coats the conductive metal portion, wherein said coating is hydrophilic;   wherein the solution of unassembled plasmonic nanoparticles has an optical density of at least about 1 O.D. at one or more peak resonance wavelengths;   distributing the solution from the skin surface to a portion of a pilosebaceous unit;   removing the solution from the skin surface while leaving the solution localized within the portion of the pilosebaceous unit; and   irradiating the solution with an energy wavelength in the near-infrared range thereby inducing a surface plasmon in said plasmonic nanoparticles, thereby localizing thermal damage to said portion of the pilosebaceous unit.   
     
     
         2 . The method of  claim 1 , further comprising:
 pre-treating the skin surface, prior to irradiating, to increase distribution from the skin surface to the pilosebaceous unit, wherein pre-treating the skin surface comprises at least one of the group consisting of: hair removal and fractionated photothermolysis laser treatment.   
     
     
         3 . The method of  claim 1 , wherein distributing the solution of plasmonic nanoparticles comprises distribution with a mechanical vibration device, wherein the mechanical vibration device comprises an ultrasound device. 
     
     
         4 . The method of  claim 1 , wherein the conductive metal portion is a nanoplate, and wherein the coating comprises any one of silica and polyethylene glycol (PEG). 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein the solution of unassembled plasmonic nanoparticles has an optical density of at least about 1 O.D. at a resonance wavelength of about 810 nanometers. 
     
     
         7 . The method of  claim 1 , wherein the solution of unassembled plasmonic nanoparticles has an optical density of at least about 1 O.D. at a resonance wavelength of about 1,064 nanometers. 
     
     
         8 . The method of  claim 1 , wherein the solution of unassembled plasmonic nanoparticles has an optical density of about 250 O.D. 
     
     
         9 . The method of  claim 1 , wherein the conductive metal portion comprises gold. 
     
     
         10 . The method of  claim 1 , wherein the conductive metal portion comprises silver. 
     
     
         11 . The method of  claim 1 , wherein the conductive metal portion comprises nickel. 
     
     
         12 . The method of  claim 1 , wherein the conductive metal portion comprises platinum. 
     
     
         13 . The method of  claim 1 , wherein the conductive metal portion comprises titanium. 
     
     
         14 . The method of  claim 1 , wherein the plasmonic nanoparticles are nanoshells. 
     
     
         15 . The method of  claim 1 , wherein the nanoshells have a diameter of about 150 nm. 
     
     
         16 . The method of  claim 15 , wherein the nanoshells comprise a silica core and a gold shell. 
     
     
         17 . The method of  claim 16 , wherein the silica core has a diameter of 120 nm. 
     
     
         18 . The method of  claim 16 , wherein the gold shell has a thickness of 15 nm. 
     
     
         19 . The method of  claim 1 , wherein the coating comprises polyethylene glycol (PEG). 
     
     
         20 . A method of localizing thermal damage to a pilosebaceous unit, comprising:
 topically applying a solution of unassembled plasmonic nanoparticles to a skin surface;   wherein the solution of plasmonic nanoparticles has at least one peak absorption wavelength in the near-infrared range,   wherein the the solution of unassembled plasmonic nanoparticles has an optical density of at least about 1 O.D. at one or more peak resonance wavelengths,   wherein the plasmonic nanoparticles comprise a conductive metal portion,   wherein the conductive metal portion comprises at least one of gold, silver, nickel, platinum, and titanium,   wherein the plasmonic nanoparticles comprise a coating that coats the conductive metal portion, wherein said coating is hydrophilic;   targeting a pilosebaceous unit by redistributing the solution of plasmonic nanoparticles from the skin surface to the pilosebaceous unit, wherein redistributing solution of plasmonic nanoparticles comprises distribution with a mechanical vibration device;   removing the solution from the skin surface while leaving the solution localized within the pilosebaceous unit; and   exposing the solution of plasmonic nanoparticles to an energy source to induce a surface plasmon in said plasmonic nanoparticles, thereby localizing thermal damage to said pilosebaceous unit.   
     
     
         21 .- 50 . (canceled) 
     
     
         51 . A composition comprising a plurality of plasmonic nanoparticles in an amount effective to induce selective thermoablation in a target tissue region with which the composition is contacted.