Zhai Xi, Yokota Miki, Maibach Howard I
Department of Dermatology, University of California, School of Medicine, San Francisco, California 94143-0989, USA.
Cutan Ocul Toxicol. 2007;26(2):107-11. doi: 10.1080/15569520701212191.
Wound dressings' occlusivity is directly correlated with water permeability and may affect wound healing. This study evaluated the wound dressings' occlusivity in comparison to their ability to retain water in an in vitro human skin model. Human cadaver skin was stretched over fully filled vials of physiological saline and banded. After 30 minutes, during which equilibrium was established, baseline values for transepidermal water loss (TEWL) were measured. Then an occlusive film was placed over one skin, a semi-occlusive dressing over another and finally 100 microL of a 5% copolymer solution over the third piece of skin, which was then allowed to aerate until it formed a thin membrane. One skin sample was left fully exposed to the air, serving as a blank control. After 30 minutes post-treatment, the TEWL was re-measured for all the samples. TEWL values showed the occlusive film was the most water-impermeable, allowing only a mean of 1.6 g/m(2) hours of water to pass through and thus also showing a significant difference (p < 0.05) in comparison to the blank (untreated) control. Furthermore, the semi-occlusive membrane decreased TEWL but not significantly, whereas the film former appeared to have no effect. We found no significant decrease in TEWL in the semi-occlusive membrane and even in the film former. This in vitro model provides a fast and economical method of screening the effect of occlusivity in wound dressings.
伤口敷料的封闭性与透水性直接相关，可能会影响伤口愈合。本研究在体外人体皮肤模型中，对比了伤口敷料的封闭性与其保水能力。将人体尸体皮肤拉伸覆盖在装满生理盐水的小瓶上并用绷带固定。30分钟内建立平衡，测量经表皮水分流失（TEWL）的基线值。然后在一块皮肤上覆盖封闭性薄膜，在另一块皮肤上覆盖半封闭性敷料，最后在第三块皮肤上滴加100微升5%的共聚物溶液，之后使其通气直至形成薄膜。留一块皮肤样本完全暴露在空气中作为空白对照。处理30分钟后，重新测量所有样本的TEWL。TEWL值显示封闭性薄膜的透水性最差，平均每平方米每小时仅允许1.6克水通过，因此与空白（未处理）对照相比也显示出显著差异（p < 0.05）。此外，半封闭性薄膜降低了TEWL，但不显著，而成膜剂似乎没有效果。我们发现半封闭性薄膜甚至成膜剂的TEWL都没有显著降低。这种体外模型提供了一种快速且经济的方法来筛选伤口敷料封闭性的效果。
