Structure and Mechanical Response of Protein Hydrogels Reinforced by Block Copolymer Self-Assembly.
Structure and Mechanical Response of Protein Hydrogels Reinforced by Block Copolymer Self-Assembly.
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DOI：
10.1039/c3sm00102d
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发表时间：
2013-08-07
期刊：
影响因子：
3.4
通讯作者：
Olsen BD
中科院分区：
文献类型：
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作者：
Glassman MJ;Olsen BD
一种用于响应性增韧可注射蛋白质水凝胶的策略已经通过将缔合蛋白质作为中间嵌段并入具有温敏性聚（N-异丙基丙烯酰胺）（PNIPAM）末端嵌段的三嵌段共聚物中来实施，从而产生具有注射性所需的低屈服应力和注射后承重应用所需的耐久性的材料。由PNIPAM关联触发的响应性增强导致凝胶的弹性模量以及其抗蠕变性的显著增加。这些材料的性能是分子设计的强大功能，某些配方达到高达130 kPa的弹性模量，有效地增强了其低温模量的14倍，并且应力松弛时间增加了高达50倍。这些温敏增强的纳米结构的起源进行了探索，表明大胶束核心，高PNIPAM体积分数，和高密度的关联基团在蛋白质冠导致最大的增强凝胶的弹性模量。具有最大胶束和最高填充分数的凝胶在增强状态下也具有最长的弛豫时间。这些结合的结构和力学的研究表明，胶束和蛋白质网络的控制是至关重要的，使高性能凝胶相关的生物医学应用。
A strategy for responsively toughening an injectable protein hydrogel has been implemented by incorporating an associative protein as the midblock in triblock copolymers with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) endblocks, producing materials with a low yield stress necessary for injectability and durability required for load-bearing applications post-injection. Responsive reinforcement triggered by PNIPAM association leads to significant increases in the gel’s elastic modulus as well as its resistance to creep. The performance of these materials is a strong function of molecular design, with certain formulations reaching elastic moduli of up to 130 kPa, effectively reinforced by a factor of 14 over their low temperature moduli, and having stress relaxation times increased by up to a factor of 50. The nanostructural origins of these thermoresponsive enhancements were explored, demonstrating that large micellar cores, high PNIPAM volume fractions, and high densities of associating groups in the protein corona lead to the greatest reinforcement of the gel’s elastic modulus. Gels with the largest micelles and the highest packing fractions also had the longest relaxation times in the reinforced state. These combined structure and mechanics studies reveal that control of both the micellar and protein networks is critical for making high performance gels relevant for biomedical applications.