Tensile mechanical properties of three-dimensional type I collagen extracellular matrices with varied microstructure
Tensile mechanical properties of three-dimensional type I collagen extracellular matrices with varied microstructure
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DOI：
10.1115/1.1449904
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发表时间：
2002-04-01
影响因子：
1.7
通讯作者：
Voytik-Harbin, SL
中科院分区：
文献类型：
--
作者：
Roeder, BA;Kokini, K;Voytik-Harbin, SL
必须确定特定微观结构和机械设计参数的重要性和优先级，以有效地设计模拟细胞外基质（ECM）环境并作为组织替代品具有临床应用的支架（生物材料）。在这个研究中，v。由结缔组织 ECM 的主要成分和结构成分 I 型胶原制备三维 (3-D) 基质，并研究了结构-机械关系。改变聚合条件，包括胶原蛋白浓度 (0.3-3 mg/mL) 和 pH (6-9)，以获得具有不同微观结构的胶原原纤维基质，使用共焦反射显微镜评估特定的微观结构特征（例如，直径和长度）和 3-D 成分原纤维的组织。微观结构分析表明，胶原浓度的变化会影响原纤维密度，同时保持相对恒定的原纤维直径。另一方面，原纤维长度和直径均受到聚合反应 pH 值的影响。从机械角度来看，所有基体都表现出相似的应力-应变曲线，具有可识别的“脚趾”、“线性”和“失效”区域。然而，线性模量和失效应力随着胶原浓度的增加而增加，并且与原纤维密度的增加相关。线性模量和失效应力均显示出随 pH 值的增加而增加，这与空气原纤维长度的增加和原纤维直径的减小有关。胶原基质的拉伸机械性能也显示出应变率依赖性。有关 ECM 及其组成分子的 3D 微观结构机械性能的基本信息对于我们全面了解细胞-ECM 相互作用（例如力传导）以及开发组织修复和替换的新策略非常重要。
The importance and priority of specific micro-structural and mechanical design parameters must be established to effectively engineer scaffolds (biomaterials) that mimic the extaracellular matrix (ECM) environment of cells and have clinical applications as tissue substitutes. In this stud,v. three-dimensional (3-D) matrices were prepared from type I collagen, the predominant compositional and structural component of connective tissue ECMs, and structural-mechanical relationships were studied. Polymerization conditions, including collagen concentration (0.3-3 mg/mL) and pH (6-9), were varied to obtain matrices of collagen fibrils with different microstructures, Confocal reflection microscopy was used to assess specific micro-structural features (e.g,, diameter and length) and organization of component fibrils in 3-D. Microstructural analyses revealed that changes in collagen concentration affected fibril density while maintaining a relatively constant fibril diameter On the other hand, both fibril length and diameter were affected by the pH of the polymerization reaction. Mechanically, all matrices exhibited a similar stress-strain curve with identifiable "toe," "linear," and ",failure " regions. However, the linear modulus and failure stress increased with collagen concentration and were correlated with an increase in fibril density, Additionally. both the linear modulus and failure stress showed an increase with pH, which was related to air increased fibril length and a decreased fibril diameter The tensile mechanical properties of the collagen matrices also showed strain rate dependence, Such fundamental information regarding the 3-D microstructural-mechanical properties of the ECM and its component molecules are important to our overall understanding of cell-ECM interactions (e.g., mechanotransduction) and the development of novel strategies for tissue repair and replacement.