Treatment of Alopecia By Micropore Delivery of Stem Cells
A method of restoring hair to skin that has suffered hair loss includes optically ablating an array of spaced-apart microchannels or voids into the skin and transplanting into the voids stem cells, a scaffold and a differentiation factor for causing the stem cells to differentiate into hair follicles.
1 . A method of treating or preventing hair loss in a subject in need thereof, the method comprising:
irradiating skin with pulses of laser irradiation at a rate of 10 per second to 5000 per second and at a pulse energy of up to 150 mJ per pulse to form a plurality of micropore channels, wherein the micropore channels extend into dermis of the skin; and
implanting a composition into the micropore channel,
wherein the composition comprises stem cells and a growth media, the laser irradiation has an absorption coefficient in water of about 100 cm −1 to 12,300 cm −1 , the micropore channels have a depth of about 200 μm to 4 mm and a density of less than 2500 voids per cm 2 per pass, and viable tissue separating adjacent micropore channels has a width, at a narrowest point thereof, between about 50 μm and 500 μm.
2 . The method of claim 1 , wherein the composition is implanted 1 min after the formation of the plurality of micropore channels.
3 . The method of claim 2 , wherein the composition is implanted 1 hr after the formation of the plurality of micropore channels.
4 . The method of claim 3 , wherein the composition is implanted 1 day after the formation of the plurality of micropore channels.
5 . The method of claim 1 , wherein the plurality of micropore channels are elongated.
6 . The method of claim 5 , wherein the viable tissue separates the plurality of elongated micropore channels.
7 . The method of claim 1 , wherein the composition further comprises a scaffold.
8 . The method of claim 7 , wherein the scaffold is selected from the group consisting of poly(lactic-co-glycolic acid) (PLGA), fibronectin, collagen 1, and collagen 3.
9 . The method of claim 8 , wherein the scaffold is PLGA.
10 . The method of claim 1 , wherein the stem cell is an embryonic stem cell, fetal stem cell, umbilical cord blood stem cell or an adult stem cell
11 . The method of claim 10 , wherein the stem cell is an adult stem cell.
12 . The method of claim 11 , wherein the adult stem cell is derived from adipose tissue, hair follicle, or bone marrow.
13 . The method of claim 12 , wherein the stem cell is hair follicle cell.
14 . The method of claim 10 , wherein the composition further comprises a melanocyte stem cell.
15 . The method of claim 1 , wherein the growth media comprises a proliferation-inducing growth factor.
16 . The method of claim 15 , wherein the growth factor is selected from the group consisting of epidermal growth factor (EGF), amphiregulin, acidic fibroblast growth factor (aFGF or FGF-1), basic fibroblast growth factor (bFGF or FGF-2), and transforming growth factor alpha (TGFα), or combinations thereof.
17 . The method of claim 1 , further comprising:
administering a hair-follicle differentiation factor.
18 . The method of claim 17 , wherein the differentiation factor is selected from the group consisting of FGF2, FGF4, noggin, PDGF, and PTHrp, or combinations thereof.