Cellular behaviors on polymeric scaffolds with 2D-patterned mechanical properties

Two-Dimensional Cellular Patterning on a Polymer Film Based on Interfacial Stiffness

The mechanical properties in the outermost region of a polymer film strongly affect various material functions. We here propose a novel and promising strategy for the two-dimensional regulation of the mechanical properties of a polymer film at the water interface based on an inkjet drawing of silica nanoparticles (SNPs) underneath it. A film of poly(2-hydroxyethyl methacrylate) (PHEMA), which exhibits excellent bioinertness properties at the water interface, was well fabricated on a substrate with a pattern of SNPs. X-ray photoelectron spectroscopy and atomic force microscopy confirmed that the surface of the PHEMA film was flat and chemically homogeneous. However, the film surface was in-plane heterogeneous in stiffness due to the presence of the underlying SNP lines. It was also noted that NIH/3T3 fibroblast cells selectively adhered and formed aggregates on the areas under which an SNP line was drawn.

Mesoscopic heterogeneity in a nanocellulose-containing cell storage medium

A nanocellulose (NC)-containing medium is a promising candidate for cell storage that allows cell floating without any stirring. We here found that the NC medium was spatially heterogeneous in terms of its rheological properties. The characteristic length of the heterogeneity was a few tens of micrometers and it decreased upon sonication treatment. The length scale of the heterogeneity affected the cell suspension; the NC medium having a smaller length scale suppressed the cell sedimentation effectively.