Hierarchical Characterization and Nanomechanical Assessment of Biomimetic Scaffolds Mimicking Lamellar Bone via Atomic Force Microscopy Cantilever-Based Nanoindentation
Hierarchical Characterization and Nanomechanical Assessment of Biomimetic Scaffolds Mimicking Lamellar Bone via Atomic Force Microscopy Cantilever-Based Nanoindentation
复制标题
通过原子力显微镜悬臂纳米压痕模拟板层骨的仿生支架的层次表征和纳米力学评估
作者：
Brian Wingender;Yongliang Ni;Yifan Zhang;C. Taylor;L. Gower
骨的层次化结构及其两个主要成分碳化磷灰石和纤维状胶原的内在材料特性，当协同组织成相互渗透的硬-软复合材料时，有助于其优异的力学性能。板层骨是哺乳动物硬组织中的主要结构基元，因此，我们认为，具有模拟骨的分层结构的胶原/磷灰石复合材料的制备，包括致密的板层微结构和矿化的胶原纤维纳米结构，是迈向再生骨组织工程目标的重要的第一步。在这项工作中，我们利用胶原的液晶特性来制备致密的基质，这些基质以胆甾型结构组装。基质通过碳二亚胺化学交联以改善机械性能，随后通过聚合物诱导液体前体(PILP)过程进行矿化以促进纤维内矿化。交联过程和矿化过程都不影响胆固醇型胶原的微观结构；值得注意的是，通过悬臂梁原子力显微镜(AFM)纳米压痕测量，随着交联密度的增加，有更高的硬度的积极趋势。在干燥状态下，中等(X51；4.8±4.3 GPA)和高(X76；7.8±6.7 GPA)交联PILP矿化液晶胶原(LCC)支架的平均弹性模量高于牛骨的平均弹性模量(5.5±5.6 GPA)。
The hierarchical structure of bone and intrinsic material properties of its two primary constituents, carbonated apatite and fibrillar collagen, when being synergistically organized into an interpenetrating hard-soft composite, contribute to its excellent mechanical properties. Lamellar bone is the predominant structural motif in mammalian hard tissues; therefore, we believe the fabrication of a collagen/apatite composite with a hierarchical structure that emulates bone, consisting of a dense lamellar microstructure and a mineralized collagen fibril nanostructure, is an important first step toward the goal of regenerative bone tissue engineering. In this work, we exploit the liquid crystalline properties of collagen to fabricate dense matrices that assemble with cholesteric organization. The matrices were crosslinked via carbodiimide chemistry to improve mechanical properties, and are subsequently mineralized via the polymer-induced liquid-precursor (PILP) process to promote intrafibrillar mineralization. Neither the crosslinking procedure nor the mineralization affected the cholesteric collagen microstructures; notably, there was a positive trend toward higher stiffness with increasing crosslink density when measured by cantilever-based atomic force microscopy (AFM) nanoindentation. In the dry state, the average moduli of moderately (X51; 4.8 ± 4.3 GPa) and highly (X76; 7.8 ± 6.7 GPa) crosslinked PILP-mineralized liquid crystalline collagen (LCC) scaffolds were higher than the average modulus of bovine bone (5.5 ± 5.6 GPa).
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影响因子：
9.7
作者：
Rodriguez, Douglas E.;Thula-Mata, Taili;Toro, Edgardo J.;Yeh, Ya-Wen;Holt, Carl;Holliday, L. Shannon;Gower, Laurie B.
通讯作者：
Gower, Laurie B.
影响因子：
3
作者：
Balooch, M.;Habelitz, S.;Marshall, G. W.
通讯作者：
Marshall, G. W.
影响因子：
9.7
作者：
Thula, Taili T.;Rodriguez, Douglas E.;Lee, Myong Hwa;Pendi, Laura;Podschun, Jacob;Gower, Laurie B.
通讯作者：
Gower, Laurie B.
影响因子：
4
作者：
Grant, Colin A.;Brockwell, David J.;Thomson, Neil H.
通讯作者：
Thomson, Neil H.
影响因子：
3.4
作者：
Grant, Colin A.;Brockwell, David J.;Thomson, Neil H.
通讯作者：
Thomson, Neil H.