Image credit: Tokyo University of Agriculture and Technology
In application, strength and stability of single microgels are important for controlling functions. However, their mechanical properties have been little known due to measurement difficulty. Miho Yanagisawa and Atsushi Sakai at Tokyo University of Agriculture and Technology and their colleagues succeeded in measuring the elasticity of single microgels by pulling the with a microcapillary and quantifying deformation and pressure during aspiration.
Through analysis of size dependence on elasticity of gelatin microgels formed inside cell-mimicked small mold (1/10th to 1/1000th of a millimeter), they discovered that cell-sized mold makes gelatin gels 10 times stiffer. Detailed analysis of molecular structure in the gelatin microgels revealed that an increase of β sheet from interaction with lipid membrane covering the cell-mimicked mold is the factor for the higher stiffness.
These findings indicate mechanical properties of gels can be controlled by modulating space sizes for gelation. In terms of application of these findings, development of novel functionalization methods for various biopolymer gels and elucidation of mechanical properties of biopolymer gels in living cells such as cytoskeletal gels are expected.