Alberti Kyle A, Sun Jeong-Yun, Illeperuma Widusha R, Suo Zhigang, Xu Qiaobing
Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts, 02155, USA.
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, 02138, USA ; Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge MA, 02138, USA ; Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744 Korea.
J Mater Sci. 2015 Mar;50(6):2616-2625. doi: 10.1007/s10853-015-8842-2.
A strong isotropic material that is both biocompatible and biodegradable is desired for many biomedical applications, including rotator cuff repair, tendon and ligament repair, vascular grafting, among others. Recently, we developed a technique, called "bioskiving" to create novel 2D and 3D constructs from decellularized tendon, using a combination of mechanical sectioning, and layered stacking and rolling. The unidirectionally aligned collagen nanofibers (derived from sections of decellularized tendon) offer good mechanical properties to the constructs compared with those fabricated from reconstituted collagen.
In this paper, we studied the effect that several variables have on the mechanical properties of structures fabricated from tendon slices, including crosslinking density and the orientation in which the fibers are stacked.
We observed that following stacking and crosslinking, the strength of the constructs is significantly improved, with crosslinked sections having an ultimate tens ile strength over 20 times greater than non-crosslinked samples, and a modulus nearly 50 times higher. The mechanism of the mechanical failure mode of the tendon constructs with or without crosslinking was also investigated.
The strength and fiber organization, combined with the ability to introduce transversely isotropic mechanical properties makes the laminar tendon composites a biocompatiable material that may find future use in a number of biomedical and tissue engineering applications.
许多生物医学应用，包括肩袖修复、肌腱和韧带修复、血管移植等，都需要一种具有生物相容性和可生物降解性的强各向同性材料。最近，我们开发了一种名为“生物切片”的技术，通过机械切片、分层堆叠和轧制相结合的方式，从脱细胞肌腱中创建新型的二维和三维结构。与由重组胶原蛋白制成的结构相比，单向排列的胶原纳米纤维（源自脱细胞肌腱切片）为这些结构提供了良好的力学性能。
在本文中，我们研究了几个变量对由肌腱切片制成的结构的力学性能的影响，包括交联密度和纤维堆叠的方向。
我们观察到，在堆叠和交联后，结构的强度显著提高，交联部分的极限拉伸强度比未交联样品高20倍以上，模量高出近50倍。我们还研究了交联或未交联的肌腱结构的机械失效模式机制。
强度和纤维组织，以及引入横向各向同性力学性能的能力，使层状肌腱复合材料成为一种生物相容性材料，可能在未来的许多生物医学和组织工程应用中得到应用。
