This
Letter examines the physical and chemical changes that occur
at the interface of methyl-terminated alkanethiol self-assembled monolayers
(SAMs) after exposure to cell culture media used to derive embryoid
bodies (EBs) from pluripotent stem cells. Attenuated total reflectance
Fourier transform infrared (ATR-FTIR) spectroscopy analysis of the
SAMs indicates that protein components within the EB cell culture
medium preferentially adsorb at the hydrophobic interface. In addition,
we examined the adsorption process using surface plasmon resonance
and atomic force microscopy. These studies identify the formation
of a porous, mat-like adsorbed protein film with an approximate thickness
of 2.5 nm. Captive bubble contact angle analysis reveals a shift toward
superhydrophilic wetting behavior at the cell culture interface due
to adsorption of these proteins. These results show how EBs are able
to remain in suspension when derived on hydrophobic materials, which
carries implications for the rational design of suspension culture
interfaces for lineage specific stem-cell differentiation