Probing the alignment-dependent mechanical behaviors and time-evolutional aligning process of collagen scaffolds
Probing the alignment-dependent mechanical behaviors and time-evolutional aligning process of collagen scaffolds
复制标题
探讨胶原支架的对齐依赖机械行为和时间演化对齐过程
DOI：
10.1039/d2tb01360f
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发表时间：
2022
影响因子：
7
通讯作者：
Yeo, Jingjie
中科院分区：
文献类型：
--
作者：
Zhai, Chenxi;Sullivan, Patrick A.;Martin, Cassandra L.;Shi, Haoyuan;Deravi, Leila F.;Yeo, Jingjie
在体外有效地操纵和复制胶原蛋白 (COL) 排列仍然具有挑战性，因为许多潜在和指导排列过程的基本机制尚不清楚。我们协调实验和粗粒度分子动力学模拟，以研究不断生长的 COL 支架的机械行为，并分析纤维排列和各种交联密度的变化如何影响其在剪切流下的排列动态。我们发现较高的交联密度和排列水平显着提高了本体 COL 系统的表观拉伸/剪切模量和强度，这表明了促进设计更强的 COL 基材料的潜在措施。由于原纤维排列在支架力学中起着关键因素，接下来我们通过计算研究 COL 的结构特性（如链长、链数、束缚条件和初始 COL 构象）对 COL 最终排列水平的影响，研究原纤维排列与库埃特流背后的分子机制。我们的计算表明，更长的链长、更多的链、更多的束缚和初始各向异性 COL 构象有利于最终的比对，但链长的影响可能比其他因素更占主导地位。这些结果为制造基于 COL 的支架提供了重要的考虑参数，其中对齐和交联对于调节性能是必要的。
Efficiently manipulating and reproducing collagen (COL) alignment in vitro remains challenging because many of the fundamental mechanisms underlying and guiding the alignment process are not known. We reconcile experiments and coarse-grained molecular dynamics simulations to investigate the mechanical behaviors of a growing COL scaffold and assay how changes in fiber alignment and various cross-linking densities impact their alignment dynamics under shear flow. We find higher cross-link densities and alignment levels significantly enhance the apparent tensile/shear moduli and strength of a bulk COL system, suggesting potential measures to facilitate the design of stronger COL based materials. Since fibril alignment plays a key factor in scaffold mechanics, we next investigate the molecular mechanism behind fibril alignment with Couette flow by computationally investigating the effects of COL's structural properties such as chain lengths, number of chains, tethering conditions, and initial COL conformations on the COL's final alignment level. Our computations suggest that longer chain lengths, more chains, greater amounts of tethering, and initial anisotropic COL conformations benefit the final alignment, but the effect of chain lengths may be more dominant over other factors. These results provide important parameters for consideration in manufacturing COL-based scaffolds where alignment and cross-linking are necessary for regulating performance.