Terzini Mara, Bignardi Cristina, Castagnoli Carlotta, Cambieri Irene, Zanetti Elisabetta M, Audenino Alberto L
Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
Department of Engineering, University of Perugia, Perugia, Italy.
Open Biomed Eng J. 2016 Apr 8;10:34-42. doi: 10.2174/1874120701610010034. eCollection 2016.
The dermis is a commonly used source tissue for biologic scaffolds; all cellular and nuclear materials need to be removed to limit the inflammatory immune response by the host organism. The decellularization is critical because it must preserve the structural integrity of the extracellular matrix. This work has analyzed a decellularization procedure commonly followed for the dermal tissue that is a chemical treatment with sodium hydroxide. The goal of this work is to identify the optimal treatment length on the basis of structural properties.
Tensile tests have been performed on the native tissue and on tissues decellularized for 1-7 weeks in sodium hydroxide. The collected data have been analyzed through Tukey-Kramer test to assess if the mechanical properties (ultimate tensile stress and elastic modulus) of decellularized tissues were significantly different from the properties of the native tissue. These tests have been performed on specimens cut along two orthogonal directions (parallel and perpendicular to Langer's lines).
The decellularization treatment performed with sodium hydroxide in general weakens the tissue: both the ultimate stress and the elastic modulus get lower. The structural properties along Langer lines orientation are more strongly impacted, while the structural properties orthogonal to Langer lines can be preserved with an optimal duration of the decellularization treatment that is 5-6 weeks.
The duration of the decellularization treatment is critical not only to reach a complete decellularization, but also to preserve the mechanical properties of the tissue; 5-6 week treatment performed with sodium hydroxide allows preserving the mechanical properties of the native tissue perpendicularly to Langer lines orientation, and minimizing the impact of the decellularization process on the mechanical properties along the Langer lines orientation.
真皮是生物支架常用的来源组织；所有细胞和核物质都需要去除，以限制宿主生物体的炎性免疫反应。去细胞化至关重要，因为它必须保持细胞外基质的结构完整性。这项工作分析了一种常用于真皮组织的去细胞化程序，即使用氢氧化钠进行化学处理。这项工作的目标是根据结构特性确定最佳处理时长。
对天然组织以及在氢氧化钠中去细胞化1至7周的组织进行了拉伸试验。通过Tukey-Kramer检验对收集到的数据进行分析，以评估去细胞化组织的力学性能（极限拉伸应力和弹性模量）与天然组织的性能是否存在显著差异。这些试验在沿两个正交方向（平行和垂直于朗格线）切割的标本上进行。
一般来说，用氢氧化钠进行的去细胞化处理会使组织变弱：极限应力和弹性模量都会降低。沿朗格线方向的结构特性受到的影响更大，而垂直于朗格线的结构特性可以通过5至6周的最佳去细胞化处理时长得以保留。
去细胞化处理的时长不仅对于实现完全去细胞化至关重要，而且对于保留组织的力学性能也很关键；用氢氧化钠进行5至6周的处理能够保留天然组织垂直于朗格线方向的力学性能，并将去细胞化过程对沿朗格线方向力学性能的影响降至最低。
