METHODS FOR DELIVERY OF SUB-SURFACE ARRAY OF ABSORBER MATERIALS AND METHODS OF LIGHT IRRADIATION THERAPY
Methods for injecting light absorbing materials or particles into the skin and irradiating the materials or particles to create zones of thermal injury are provided. Such methods can be used to treat the effects of aging and/or photoaging, among other indication.
1 . A method for treating skin comprising
injecting an amount of light absorbing material at a target zone beneath the skin in a predetermined pattern at a predetermined depth; and
irradiating the light absorbing material to selected wavelengths of light, thereby causing at least one zone of thermal injury.
2 . The method of claim 1 , wherein the injecting comprises injecting using a single needle.
3 . The method of claim 1 , wherein the injecting comprises injecting using a microneedle array.
4 . The method of claim 3 , wherein injecting the light absorbing material comprises depressing a reservoir in fluid connection with at least one of the needles in the microneedle array.
5 . The method of claim 4 , wherein depressing the reservoir can be performed manually or using a delivery device.
6 . The method of claim 1 , wherein the predetermined pattern comprises regularly spaced rows and columns.
7 . The method of claim 1 , wherein the predetermined pattern is irregular.
8 . The method of claim 1 , wherein the light absorbing material is configured to absorb light at a wavelength of about 800 nm to about 1,200 nm.
9 . The method of claim 1 , wherein irradiating the light absorbing material comprises exposing the light absorbing material to light with a wavelength band of about 700 to about 1,200 nm.
10 . The method of claim 1 , wherein injecting an amount of light absorbing material comprises injecting at a depth of about 50 microns to about 2 mm.
11 . The method of claim 1 , wherein a diameter of the thermal damage zone is about 50 microns to about 1 mm.
12 . The method of claim 1 , wherein irradiating the light absorbing material causes a plurality of zones of thermal injury, and wherein a density of the thermal damage zones is about 10 per cm2 to about 15,000 per cm2.
13 . The method of claim 1 , wherein an absorption coefficient in the target zone is about 1.0 to about 1,000 (l/cm).
14 . A device for treating skin, comprising
an array of microneedles; and
a reservoir configured to hold fluid comprising a light absorbing material fluidly connected to at least one of the microneedles.
15 . The device of claim 14 , wherein the array comprises microneedles in regular rows and columns.
16 . The device of claim 14 , wherein the array comprises microneedles arranged in an irregular pattern.
17 . The device of claim 14 , wherein the device is contoured to match to a treatment site of a patient.
18 . The device of claim 14 , wherein the device is a platform comprising a large microneedle array or a plurality of microneedle arrays.
19 . The device of claim 14 , wherein the device comprises at least two reservoirs, each reservoir fluidly connected to at least one microneedle.
20 . The device of claim 14 , wherein the device comprises a rectangular or ovular shape.
21 . The method of claim 9 , wherein the pulse duration of the laser matches or is lower than the thermal relaxation time of the zone of the light absorbing material and is in the range of 0.1 ms to 200 ms.