The precise removal of stratum corneum from cadaveric swine skin by a mid-infrared erbium: yttrium scandium gallium garnet laser (γ = 2.79 μm; 250 μsec pulse width) was assessed by electrical resistance measurements and documented by histology. The effects of stratum corneum removal by laser ablation and by adhesive tape-stripping on the in vitro penetration of 3H-hydrocortisone and 1251-γ-interferon were determined. Excised swine skin was irradiated with laser (1 J/cm2; 31 mJ/pulse; 1 Hz; 2 mm spot diameter). For skin penetration studies, laser pulses were delivered to discrete 2-mm areas to ablate up to 12.6% of the total 3-cm2 stratum corneum diffusional area. Franz in vitro skin penetration chambers were used to measure the cumulative 48-h penetration of 3H-hydrocortisone and 1251-γ-interferon in laser-treated and tape-stripped skin. Electrical resistance measurements and histologic studies demonstrated that 10-14 laser pulses at the above energy density were required to abolish skin resistance and selectively ablate stratum corneum without damage to adjacent dermal structures. Laser ablation of 12.6% of the surface area of stratum corneum produced a 2.8 and 2.1-times increase in permeability constant (kp) for 3H-hydrocortisone and 1251-γ-interferon, respectively. These studies demonstrate that a pulsed mid-infrared laser can reliably and precisely remove the stratum corneum, facilitating penetration of large molecules such as 125I γ-interferon that cannot penetrate intact skin. This new technique may be useful for basic and clinical investigation of skin barrier properties.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Investigative Dermatology|
|Publication status||Published - Nov 1991|
ASJC Scopus subject areas