Seki Taiga, Arai Noriyoshi, Suh Donguk, Ozawa Taku, Shimada Tomoko, Yasuoka Kenji, Hotta Atsushi
Department of Mechanical Engineering, Keio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan
Department of Mechanical Engineering, Kindai University 3-4-1 Kowakae Higashiosaka Osaka 577-8522 Japan.
RSC Adv. 2018 Jul 24;8(47):26461-26468. doi: 10.1039/c8ra04692a.
Peptide amphiphiles are one of the most promising materials in the biomedical field, so much effort has been devoted to characterizing the mechanism of their self-assembly and thermosensitive gelation. In this work, vapor pressure osmometry measurements were carried out to parameterize the thermosensitivity of interactions between peptide amphiphiles in an aqueous solution. The osmometry measurement verified that the peptides became more hydrophobic as temperature increased, which was quantitatively described with the Flory-Huggins parameter. Thereafter, a coarse-grained molecular model was used to simulate peptide amphiphiles dissolved in an aqueous solution. The temperature sensitive coarse-grained parameter , which is the repulsive force between the hydrophilic head of the peptide amphiphile and water was estimated from the aforementioned experimentally obtained . Furthermore, the effects of concentration and temperature on the self-assembly behavior of peptide amphiphiles were quantitatively studied by dissipative particle dynamics. The simulation results revealed that plays an important role in self-assembly characteristics and in the resulting microstructure of the peptide amphiphiles, which coincides with previous experimental and computational findings. The methodology in quantitatively linking the coarse-grained parameter from experiment and theory provides a sensible foundation for bridging future simulation studies with experimental work on macromolecules.
肽两亲分子是生物医学领域最有前景的材料之一，因此人们投入了大量精力来表征其自组装和热敏凝胶化的机制。在这项工作中，进行了蒸气压渗透压测量，以参数化肽两亲分子在水溶液中相互作用的热敏性。渗透压测量证实，随着温度升高，肽变得更加疏水，这用弗洛里-哈金斯参数进行了定量描述。此后，使用粗粒度分子模型来模拟溶解在水溶液中的肽两亲分子。温度敏感的粗粒度参数，即肽两亲分子亲水头部与水之间的排斥力，是根据上述实验获得的值估算出来的。此外，通过耗散粒子动力学定量研究了浓度和温度对肽两亲分子自组装行为的影响。模拟结果表明，该参数在肽两亲分子的自组装特性和由此产生的微观结构中起着重要作用，这与之前的实验和计算结果一致。将实验和理论中的粗粒度参数进行定量关联的方法，为将未来的模拟研究与大分子实验工作联系起来提供了合理的基础。
