Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
Sci Rep. 2016 Aug 25;6:32074. doi: 10.1038/srep32074.
Collecting human skin samples for medical research, including developing microneedle-based medical devices, is challenging and time-consuming. Researchers rely on human skin substitutes and skin preservation techniques, such as freezing, to overcome the lack of skin availability. Porcine skin is considered the best substitute to human skin, but their mechanical resemblance has not been fully validated. We provide a direct mechanical comparison between human and porcine skin samples using a conventional mechano-analytical technique (microindentation) and a medical application (microneedle insertion), at 35% and 100% relative humidity. Human and porcine skin samples were tested immediately after surgical excision from subjects, and after one freeze-thaw cycle at -80 °C to assess the impact of freezing on their mechanical properties. The mechanical properties of fresh human and porcine skin (especially of the stratum corneum) were found to be different for bulk measurements using microindentation; and both types of skin were mechanically affected by freezing. Localized in-plane mechanical properties of skin during microneedle insertion appeared to be more comparable between human and porcine skin samples than their bulk out-of-plane mechanical properties. The results from this study serve as a reference for future mechanical tests conducted with frozen human skin and/or porcine skin as a human skin substitute.
收集人体皮肤样本用于医学研究，包括开发基于微针的医疗设备，是具有挑战性和耗时的。研究人员依赖于人体皮肤替代品和皮肤保存技术，如冷冻，以克服皮肤供应不足的问题。猪皮被认为是人体皮肤的最佳替代品，但它们的机械相似性尚未得到充分验证。我们使用传统的机械分析技术（微压痕）和一种医学应用（微针插入），在 35%和 100%相对湿度下，对人体和猪皮样本进行了直接的机械比较。人体和猪皮样本在从供体手术切除后立即进行测试，并在 -80°C 下进行一次冻融循环，以评估冷冻对其机械性能的影响。使用微压痕进行的批量测量发现，新鲜人体和猪皮（特别是角质层）的机械性能不同；而且这两种类型的皮肤都受到冷冻的机械影响。在微针插入过程中皮肤的局部面内机械性能似乎比其面外机械性能更能在人体和猪皮样本之间进行比较。本研究的结果可作为未来使用冷冻人体皮肤和/或猪皮作为人体皮肤替代品进行机械测试的参考。
