J Toxicol Sci. 2010 Feb;35(1):107-13. doi: 10.2131/jts.35.107.
It is important for toxicological assessment of nanoparticles to determine the penetration of nanoparticle in skin qualitatively and quantitatively. Skin penetration of four different types of rutile titanium dioxide (TiO(2)) (T-35, 35 nm, non-coating; TC-35, 35 nm, with almina/silica/silicon coating; T-disp, 10 x 100 nm, mixture of almina coated and silicon coated particles, dispersed in cyclopentasiloxan; T-250, 250 nm, non-coating) was determined with in vitro intact, stripped, and hair-removed skin of Yucatan micropigs to study the effect of dispersion and skin conditions. The TiO(2) was suspended in a volatile silicone fluid used for cosmetics, cyclopentasiloxane, at a concentration of 10%. The suspension was applied at a dose 2 microl/cm(2) for 24 hr, followed by cyanoacrylate stripping. The Ti concentration in skin was determined by ICP-MS. T-35 and T-250 easily aggregated in suspension with a mean diameter greater than 1 microm. TC-35 and T-disp showed good dispersion properties with a mean diameter in suspension of approximately 100 nm. No penetration was observed regardless of TiO(2) type in intact and stripped skin. The concentration of Ti in skin was significantly higher when TC-35 was applied on hair-removed skin. SEM-EDS observation showed that Ti penetrated into vacant hair follicles (greater than 1 mm below the skin surface), however, it did not penetrate into dermis or viable epidermis.
对于纳米颗粒的毒理学评估，重要的是定性和定量地确定纳米颗粒在皮肤中的穿透性。使用体外完整、剥脱和去毛的尤卡坦微型猪皮肤，研究分散和皮肤状况的影响，确定了四种不同类型锐钛矿二氧化钛（TiO(2)）（T-35，35nm，无涂层；TC-35，35nm，带有氧化铝/二氧化硅/硅涂层；T-disp，10x100nm，氧化铝涂层和硅涂层颗粒的混合物，分散在环戊硅氧烷中；T-250，250nm，无涂层）的皮肤穿透性。TiO(2)悬浮在用于化妆品的挥发性硅酮流体环戊硅氧烷中，浓度为 10%。将悬浮液以 2μl/cm(2)的剂量应用 24 小时，然后用氰基丙烯酸酯剥离。通过 ICP-MS 测定皮肤中的 Ti 浓度。T-35 和 T-250 在悬浮液中容易聚集，平均直径大于 1μm。TC-35 和 T-disp 在悬浮液中具有良好的分散性能，平均直径约为 100nm。在完整和剥脱的皮肤中，无论 TiO(2)类型如何，都没有观察到穿透。当 TC-35 应用于去毛皮肤时，皮肤中 Ti 的浓度显著更高。SEM-EDS 观察表明 Ti 穿透到空的毛囊（皮肤表面以下大于 1mm），但未穿透真皮或有活力的表皮。
