Nondestructive, Label-Free Characterization of Mechanical Microheterogeneity in Biomimetic Materials
Nondestructive, Label-Free Characterization of Mechanical Microheterogeneity in Biomimetic Materials
复制标题
仿生材料中机械微观异质性的无损、无标记表征
DOI：
10.1021/acsbiomaterials.8b00286
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发表时间：
2018
影响因子：
5.8
通讯作者：
Hoshino, Kazunori
中科院分区：
文献类型：
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作者：
Jaiswal, Devina;Tang-Schomer, Min D.;Sood, Disha;Kaplan, David L.;Hoshino, Kazunori
我们提出了一种新的非破坏性的，无标记的，复合仿生材料的力学表征方法。该方法结合微尺度力测量，基于明场显微镜的变形分析，和有限元方法（FEM）研究生物工程复合材料的异质性。该方法被用来研究丝素蛋白为基础的，甜甜圈形的支架组成的一个壳（直径5毫米）和一个核心（直径2毫米）的硬芯或软芯配置。这些样品是基于我们以前报道的生物工程脑组织模型。当自动机械载物台压缩样品时，记录样品变形的逐步图像。还用测力传感器记录力-压缩曲线。一个MATLAB程序被用来比较和匹配光学测量的应变分布与从有限元模拟发现。迭代过程用于确定最能代表壳体和核心区域弹性模量的值。从复合材料模型中发现的计算模量与每种材料单独测量的值没有显著差异，证明了这种新方法的有效性。此外，该方法成功地测量了嵌入聚二甲基硅氧烷嵌段中的多个不同区域。这些结果表明，我们的方法在仿生复合材料结构的微观异质性表征的可行性。
We propose a novel nondestructive, label-free, mechanical characterization method for composite biomimetic materials. The method combines microscale-force measurement, bright-field microscopy based deformation analysis, and finite-element methods (FEM) to study the heterogeneity in bioengineered composite materials. The method was used to study silk fibroin protein based, donut-shaped scaffolds consisting of a shell (diameter 5 mm) and a core (diameter 2 mm) with a stiff-core or a soft-core configuration. The samples were based on our previously reported bioengineered brain tissue model. Step-wise images of sample deformation were recorded as the automated mechanical stage compressed the sample. The force–compression curves were also recorded with a load cell. A MATLAB program was used to compare and match optically measured strain distribution with that found from the FEM simulations. Iterative processes are used to determine the values that best represent the elastic moduli of the shell and the core regions. The calculated moduli found from the composite models were not significantly different from the values measured separately for each material, demonstrating the efficacy of this new approach. In addition, the method successfully measured multiple distinct regions embedded in a polydimethylsiloxane block. These results demonstrated the feasibility of our method in the microheterogeneity characterization of biomimetic composite structures.