Artificial cells such as liposomes have been applied as capsules for pharmaceutical purposes, but their fragility remains an issue. Recently, it has been reported that the mechanical reinforcement of artificial cells is possible by adding a network structure of self-assembled DNA microgels. We are currently quantifying the correlation between the skeletal structure of the DNA network and the mechanical properties of the artificial cells by micropipette aspiration, and are aiming to optimize the mechanical properties of the artificial cells in the future.

Understanding cellular mechanical properties is critical in cellular biology and bioengineering. We propose a nonlinear elastic model for droplet and shell-like lipid systems, identifying key mechanical parameters: the area-stretching modulus and the balance between interfacial and bending energies. Our model successfully characterizes mechanical properties across scales from millimeters to micrometers, demonstrating that lipid charge and DNA gel incorporation can modulate droplet mechanics. These insights offer new approaches for improving cellular systems and materials engineering.

Tardigrades are known to be tolerant to extreme environmental stresses when dehydrated, and a specific protein is expressed in large amounts in the cytoplasm during exposure to desiccation stress. Since this protein becomes stress-dependent fibrosis when expressed in human cultured cells, we are attempting to reproduce the protein fibrous structure in artificial cells and clarify the mechanical effects of protein fibrosis on the cells.

Tanaka, A., Nakano, T., Watanabe, K., Masuda, K., Honda, G., Kamata, S., ... & Kunieda, T. (2022). Stress-dependent cell stiffening by tardigrade tolerance proteins that reversibly form a filamentous network and gel. PLoS biology, 20(9), e3001780.