Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, People's Republic of China.
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
ACS Macro Lett. 2022 Jan 18;11(1):103-109. doi: 10.1021/acsmacrolett.1c00715. Epub 2021 Dec 27.
The force response of nanosized vesicles shows substantial applications in drug delivery, cancer therapies, and so on. Conventional methods in mechanical studies on vesicles rely on a camera and an optical microscope, which can hardly work for nanosized particles. Herein, we use self-assembled polydiacetylene (PDA) as a chromic mechanoresponsive group to study the responsiveness of nanovesicles under sonication. The sonication-induced deformation of the PDA backbone and reduction in its conjugation length leads to a color transition from blue to red. Three internal and external factors, including greater shear stress, lower polymerization degree, and higher viscosity of the continue phase, have been found to promote the mechanochromism of the vesicles. These results, for the first time, reveal that the force response of vesicles depends on the actual capillary number (correlated with the three explored factors), even at the nanoscale level, which opens a new avenue to mechanical modulation of nanovesicles for the development of vesicle-based bio- and nanotechniques.
纳米囊泡的力响应在药物输送、癌症治疗等方面有重要的应用。囊泡力学研究的传统方法依赖于相机和光学显微镜，但对于纳米颗粒几乎无法工作。在此，我们使用自组装聚二乙炔（PDA）作为显色力响应基团，研究超声作用下纳米囊泡的响应性。超声诱导的 PDA 主链变形和共轭长度减小导致颜色从蓝色到红色的转变。我们发现了三个内部和外部因素，包括更大的剪切应力、更低的聚合度和连续相更高的粘度，都可以促进囊泡的力致变色。这些结果首次揭示了囊泡的力响应取决于实际的毛细数（与三个探索因素相关），即使在纳米尺度，为基于囊泡的生物和纳米技术的囊泡机械调制开辟了新途径。
