The fluorospheres that penetrated through the stratum corneum represent only a small percentage of the applied beads, and the pattern of penetration was random.
Although the technique does not permit the more precise tissue localization possible with the laser scanning confocal procedure, we observed beads in the skin after no tape stripping (Figure 3A) and tape stripping 10 times (Figure 3B) and 20 times (Figure 3C), to an approximate depth of 6-7 [micro]m into the stratum corneum.
The data presented in this study demonstrate that, in conjunction with motion, fine particles penetrate the stratum corneum and lodge in the epidermis, the anatomical location of the cutaneous antigen-presenting cell, the Langerhans cell.
Activation of cutaneous immunity by percutaneous absorption of chemical through the stratum corneum is well established; however, given the long dissolution half-life for beryllium metal and its alloys, we hypothesized that beryllium particles would have to colocalize with the cutaneous antigen-presenting cell in the epidermis in order to activate a cell-mediated immune response.
1996) documented titanium dioxide penetration of the stratum corneum following repeated rubbing of sunscreen onto the volar forearm.