Dipartimento di Scienze Chimiche e Farmaceutiche , Università di Trieste , Via L. Giorgieri 1 , 34127 Trieste , Italy.
CICECO, University of Aveiro , 3810-193 Aveiro , Portugal.
ACS Nano. 2018 Jun 26;12(6):5530-5538. doi: 10.1021/acsnano.8b01182. Epub 2018 May 29.
Short peptide hydrogels are attractive biomaterials but typically suffer from limited mechanical properties. Inclusion of other nanomaterials can serve the dual purpose of hydrogel reinforcement and of conferring additional physicochemical properties ( e. g., self-healing, conductivity), as long as they do not hamper peptide self-assembly. In particular, nanocarbons are ideal candidates, and their physicochemical properties have demonstrated great potential in nanocarbon-polymer gel biomaterials for tissue engineering or drug delivery. Recently, increasing interest in supramolecular hydrogels drove research also on their enhancement with nanocarbons. However, little is known on the effect of nanocarbon morphology on the self-assembly of short peptides, which are among the most popular hydrogel building blocks. In this work, three different oxidized nanocarbons ( i. e., carbon nanotube or CNT as 1D material, graphene oxide sheet or GO as 2D material, and carbon nanohorn or CNH as 3D material) were evaluated for their effects on the self-assembly of the unprotected tripeptide Leu-Phe-Phe at physiological conditions. Supramolecular hydrogels were obtained in all cases, and viscoelastic properties were clearly affected by the nanocarbons, which increased stiffness and resistance to applied stress. Notably, self-healing behavior was observed only in the case of CNTs. Tripeptide-nanotube interaction was noted already in solution prior to self-assembly, with the tripeptide acting as a dispersing agent in phosphate buffer. Experimental and in silico investigation of the interaction between peptide and CNTs suggests that the latter acts as nucleation templates for self-assembly and reassembly. Overall, we provide useful insights for the future design of composite biomaterials with acquired properties.
短肽水凝胶是一种有吸引力的生物材料，但通常机械性能有限。只要纳米材料不阻碍肽自组装，包含其他纳米材料可以同时起到增强水凝胶和赋予额外物理化学性质（例如，自修复、导电性）的双重作用。特别是纳米碳是理想的候选材料，其物理化学性质在纳米碳-聚合物凝胶生物材料用于组织工程或药物输送方面显示出了巨大的潜力。最近，对超分子水凝胶的兴趣增加也推动了对纳米碳增强超分子水凝胶的研究。然而，对于纳米碳形态对短肽自组装的影响知之甚少，而短肽是最受欢迎的水凝胶构建块之一。在这项工作中，三种不同的氧化纳米碳（即，作为 1D 材料的碳纳米管或 CNT、作为 2D 材料的氧化石墨烯片或 GO 以及作为 3D 材料的碳纳米角或 CNH）被评估了对生理条件下未保护三肽 Leu-Phe-Phe 自组装的影响。在所有情况下都获得了超分子水凝胶，并且纳米碳明显影响了粘弹性性质，增加了刚度和对施加应力的抵抗力。值得注意的是，只有在 CNT 的情况下才观察到自修复行为。在自组装之前，在溶液中就已经注意到三肽与纳米管之间的相互作用，其中三肽在磷酸盐缓冲液中充当分散剂。对肽与 CNT 之间相互作用的实验和计算研究表明，后者充当自组装和重组的成核模板。总体而言，我们为未来设计具有获得的性质的复合生物材料提供了有用的见解。
