Wells Hannah C, Sizeland Katie H, Kirby Nigel, Hawley Adrian, Mudie Stephen, Haverkamp Richard G
School of Engineering and Advanced Technology, Massey University, Private Bag 11222, Palmerston North, New Zealand.
Australian Synchrotron, 800 Blackburn Road, Clayton, Melbourne, Victoria, Australia.
ACS Biomater Sci Eng. 2015 Oct 12;1(10):1026-1038. doi: 10.1021/acsbiomaterials.5b00310. Epub 2015 Sep 10.
Strength is an important characteristic of acellular dermal matrix (ADM) materials used for surgical scaffolds. Strength depends on the material's structure, which may vary with the source from which the product is produced, including species and animal age. Here, variations in the physical properties and structures of ADM materials from three species are investigated: bovine (fetal and neonatal), porcine, and human materials. Thickness normalized, the bovine materials have a similar strength (tear strength of 75-124 N/m) to the human material (79 N/m), and these are both stronger than the porcine material (43 N/m). Thickness-normalized tensile strengths were similar among all species (18-34 N/mm for bovine although higher in fetal material, 18 N/mm for human and 21 N/mm for porcine). Structure is investigated with synchrotron-based small-angle X-ray scattering (SAXS) for collagen fibril orientation index (OI) and scanning electron microscopy (SEM). SEM reveals a more open structure in bovine ADM than in the porcine and human material. A correlation is found between OI and thickness-normalized tear strength in neonatal bovine material measured with the X-rays edge-on to the sample, but this relationship does not extend across species. The collagen fibril arrangement, viewed perpendicular to the surface, varies between species, with the human material having a unimodal distribution and rather isotropic (OI 0.08), the porcine being strongly bimodal and rather highly oriented (OI 0.61), the neonatal bovine between these two extremes with a bimodal distribution tending toward isotropic (OI 0.14-0.21) and the fetal bovine material being bimodal and less isotropic than neonatal (OI 0.24). The OI varies less through the thickness of the porcine and human materials than through the bovine materials. The similarities and differences in structure may inform the suitability of these materials for particular surgical applications.
强度是用于手术支架的脱细胞真皮基质（ADM）材料的一项重要特性。强度取决于材料的结构，而结构可能因产品的生产来源而异，包括物种和动物年龄。在此，研究了来自三种物种的ADM材料的物理性质和结构差异：牛（胎儿和新生牛）、猪和人类材料。经厚度归一化后，牛材料的强度（撕裂强度为75 - 124 N/m）与人类材料（79 N/m）相似，且两者均强于猪材料（43 N/m）。所有物种的厚度归一化拉伸强度相似（牛为18 - 34 N/mm，胎儿材料更高，人类为18 N/mm，猪为21 N/mm）。采用基于同步加速器的小角X射线散射（SAXS）来研究胶原纤维取向指数（OI），并通过扫描电子显微镜（SEM）研究结构。SEM显示牛ADM的结构比猪和人类材料更开放。在用X射线垂直于样品边缘测量的新生牛材料中，发现OI与厚度归一化撕裂强度之间存在相关性，但这种关系并不适用于所有物种。垂直于表面观察时，胶原纤维排列在不同物种之间存在差异，人类材料具有单峰分布且各向同性相当（OI为0.08），猪材料为强烈的双峰分布且取向性相当高（OI为0.61），新生牛处于这两个极端之间，具有双峰分布且趋于各向同性（OI为0.14 - 0.21），胎儿牛材料为双峰分布且各向同性低于新生牛（OI为0.24）。猪和人类材料的OI在厚度上的变化小于牛材料。结构上的异同可能有助于确定这些材料在特定手术应用中的适用性。
