Protein Adsorption Mechanisms
Determine the Efficiency
of Thermally Controlled Cell Adhesion on Poly(<i>N</i>‑isopropyl
acrylamide) Brushes
- Publication date
- Publisher
Abstract
This study investigated the impact of the protein adsorption
mechanism(s)
on the efficiency of thermally controlled cell adhesion and release
from poly(<i>N</i>-isopropyl acrylamide) brushes. Large
format polymer gradients were used to screen for grafting densities
and substrate chemistries that alter both cell adhesion at 37 °C
and rapid cell release at 25 °C. In particular, the grafting
conditions investigated allowed protein adsorption to the underlying
substrate, penetration of the brush only, or adsorption to the outer
edge of the film. At an average molecular weight of 30 kDa (degree
of polymerization <i>N</i> ∼ 270), the results show
that robust protein adsorption to polymer brushes impairs rapid cell
release below the lower critical solution temperature. Conversely,
grafting conditions that permit protein penetration of the brush but
block strong adsorption to the underlying substrate support cell adhesion
above the transition temperature and ensure efficient cell recovery
at lower temperature. These findings demonstrate the impact of protein
adsorption mechanisms, surface chemistry, and polymer properties on
thermally controlled cell capture and release