Designed biomaterials to mimic the mechanical properties of muscles
Designed biomaterials to mimic the mechanical properties of muscles
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DOI：
10.1038/nature09024
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发表时间：
2010-05-06
期刊：
影响因子：
64.8
通讯作者：
Li, Hongbin
中科院分区：
文献类型：
--
作者：
Lv, Shanshan;Dudek, Daniel M.;Li, Hongbin
肌肉的被动弹性在很大程度上由巨肌蛋白肌联蛋白的I带部分控制（1-4），肌联蛋白是一种复杂的分子弹簧，由一系列单独折叠的免疫球蛋白样结构域以及大部分非结构化的独特序列组成（5）。这些机械元件具有不同的机械性能，并且当组合时，它们提供肌肉（6-11）的期望的被动弹性性能，其是强度、延展性和回弹性的独特组合。单分子原子力显微镜（AFM）研究表明，完整肌原纤维中肌联蛋白的宏观行为可以通过结合在单分子水平上测量的这些机械元件的机械特性来重建（8）。在这里，我们报告了人工弹性蛋白，通过结合充分表征的蛋白质结构域GB 1（12）和节枝弹性蛋白（13）来模拟肌联蛋白的分子结构。我们表明，这些人工弹性蛋白质可以光化学交联和铸造成固体生物材料。这些生物材料表现为在低应变下显示出高弹性的橡胶状材料，并且通过有效地耗散能量而在高应变下表现为减震器状材料。这些性质与肌节长度的生理范围内的肌肉的被动弹性性质相当（14），因此这些材料代表了一种新的肌肉模拟生物材料。这些生物材料的机械性能可以通过调整弹性蛋白的组成来微调，从而为开发模拟不同类型肌肉的生物材料提供了机会。我们预计这些生物材料将在组织工程中作为人造肌肉的支架和基质得到应用。
The passive elasticity of muscle is largely governed by the I-band part of the giantmuscle protein titin(1-4), a complex molecular spring composed of a series of individually folded immunoglobulin-like domains as well as largely unstructured unique sequences(5). These mechanical elements have distinct mechanical properties, and when combined, they provide the desired passive elastic properties of muscle(6-11), which are a unique combination of strength, extensibility and resilience. Single-molecule atomic force microscopy (AFM) studies demonstrated that the macroscopic behaviour of titin in intact myofibrils can be reconstituted by combining the mechanical properties of these mechanical elements measured at the single-molecule level(8). Here we report artificial elastomeric proteins that mimic the molecular architecture of titin through the combination of well-characterized protein domains GB1(12) and resilin(13). We show that these artificial elastomeric proteins can be photochemically crosslinked and cast into solid biomaterials. These biomaterials behave as rubber-like materials showing high resilience at low strain and as shock-absorber-like materials at high strain by effectively dissipating energy. These properties are comparable to the passive elastic properties of muscles within the physiological range of sarcomere length(14) and so these materials represent a new muscle-mimetic biomaterial. The mechanical properties of these biomaterials can be fine-tuned by adjusting the composition of the elastomeric proteins, providing the opportunity to develop biomaterials that are mimetic of different types of muscles. We anticipate that these biomaterials will find applications in tissue engineering(15) as scaffold and matrix for artificial muscles.