It remains a great challenge to control the morphology and size of self-assembled homopolypeptide aggregates. In this work, rod-like micelles including spindles and cylinders were prepared by a solution self-assembly of poly(γ-benzyl-L-glutamate) (PBLG) homopolypeptides with different degrees of polymerization, in which their size was controlled precisely by tuning the ratio of water/methanol in selective cosolvents. The length of the rod-like micelles increased with an increasing amount of methanol in the selective cosolvents, which was confirmed using the combination of SEM, TEM and AFM. The self-assembly mechanism of PBLG in selective cosolvents was investigated by using complementary Fourier transform infrared (FT-IR), circular dichroism (CD) and low-field NMR analyses. It was found that the shrinkage and swelling of PBLG chains play important roles in the self-assembly process. The obtained results may provide a guideline for the study of regulating the assembled aggregate sizes.

中文翻译：

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通过选择性溶剂调节同源多肽自组装的形态和大小

控制自组装同聚肽聚集体的形态和大小仍然是一个巨大的挑战。在这项工作中，包括纺锤体和圆柱体的棒状胶束是通过聚（γ-苄基-L-谷氨酸) (PBLG) 同聚肽具有不同的聚合度，通过调节选择性共溶剂中的水/甲醇比例来精确控制它们的大小。棒状胶束的长度随着选择性共溶剂中甲醇量的增加而增加，这通过 SEM、TEM 和 AFM 的组合得到证实。通过使用互补傅里叶变换红外 (FT-IR)、圆二色性 (CD) 和低场核磁共振分析，研究了 PBLG 在选择性共溶剂中的自组装机制。发现 PBLG 链的收缩和膨胀在自组装过程中起着重要作用。所得结果可为调节组装骨料尺寸的研究提供指导。