Alopecia usually cannot be cured because of the available
drug therapy being unsatisfactory. To improve the efficiency of treatment,
erbium-
yttrium-aluminum-garnet (
Er-YAG) laser treatment was conducted to facilitate skin permeation of antialopecia drugs such as
minoxidil (MXD),
diphencyprone (DPCP), and
peptide. In vitro and in vivo percutaneous absorption experiments were carried out by using nude mouse skin and porcine skin as permeation barriers. Fluorescence and confocal microscopies were used to visualize distribution of permeants within the skin.
Laser ablation at a depth of 6 and 10 μm enhanced MXD skin accumulation twofold to ninefold depending on the skin barriers selected. DPCP absorption showed less enhancement by
laser irradiation as compared with MXD. An ablation depth of 10 μm could increase the
peptide flux from zero to 4.99 and 0.33 μg cm(-2) h(-1) for nude mouse skin and porcine skin, respectively. The
laser treatment also promoted
drug uptake in the hair follicles, with DPCP demonstrating the greatest enhancement (sixfold compared with the control). The imaging of skin examined by microscopies provided evidence of follicular and intercellular delivery assisted by the
Er-YAG laser. Besides the ablative effect of removing the stratum corneum, the
laser may interact with sebum to break up the barrier function, increasing the skin delivery of antialopecia drugs. The minimally invasive, well-controlled approach of
laser-mediated
drug permeation offers a potential way to treat
alopecia. This study's findings provide the basis for the first report on
laser-assisted delivery of antialopecia drugs.