Modifying stainless steel surfaces with responsive polymers: effect of PS-PAA and PNIPAAM on cell adhesion and oil removal

Abstract

The treatment of stainless steel surfaces with responsive polymers was investigated using X-ray photoelectron spectroscopy and scanning electron microscopy. Poly(N-isopropylacrylamide) (PNIPAAM) is a temperature-sensitive polymer which is soluble in water below 32 • C (Lower Critical Solubility Temperature (LCST)) but collapses and aggregates above 32 • C. This polymer was adsorbed at 50 • C from solutions at different concentrations, followed by rinsing and different drying procedures. Thereby, a large variety of surface structures could be obtained, from smooth films to surfaces showing marked relief features due to residues of PNIPAAM aggregates. Two poly(styrene)-b-poly(acrylic acid), PS-PAA, with different block lengths, were spin-coated on stainless steel and showed preferential exposure of PS blocks at the outermost surface. PNIPAAM-conditioning was shown to strongly reduce yeast cell adhesion and to facilitate the removal of oil soil due to its high water affinity and chain mobility below the LCST. PS-PAA coatings also reduced yeast cell adhesion; this may partly be due to a reorganization of the surface, leading to exposure of PAA chains in contact with water and thus to electrostatic repulsion of the yeast cells.

The Use of Microporous Divinyl Benzene Copolymer for Yeast Cell Immobilization and Ethanol Production in Packed-Bed Reactor

“…Binding of alpha agglutinin, which is a cell adhesion glycoprotein, to its ligand alpha agglutinin mediates cell-cell contact during mating. Role of electrostatic interaction in adherence was also studied by Park et al [17] and Callewaert et al [18]. They reported that hydrophilic nature of polymers resulted in reduction in yeast cells adhesion, which agreed with our findings in this study.…”

Thermoresponsive nanocomposite double network hydrogels

“…1,2 A volume phase transition temperature ( VPTT ) of ~33–35 °C makes PNIPAAm hydrogels particularly useful to prepare “smart” materials for biological applications. 3–6 These applications include microfluidic actuation, 7–10 separation, 7,11,12 controlled drug delivery 7,13–15 and controlled detachment of adsorbed cells and proteins for cell sheet tissue engineering, 7,16,17 anti-fouling coatings, 18–20 and “self-cleaning” membranes for implanted biosensors. 21–24 …”

Thermoresponsive Double Network Micropillared Hydrogels for Controlled Cell Release

“…Thermoresponsive poly( N ‐isopropylacrylamide) (PNIPAAm) hydrogels exhibit a reversible volume phase transition from a swollen, hydrophilic state to a deswollen, hydrophobic state when heated above its volume phase transition temperature (VPTT, ≈33–35 °C) . Thus, PNIPAAm hydrogels have been studied for thermally modulated cell‐release applications, including cell sheet tissue engineering, anti‐fouling coatings, and “self‐cleaning membranes” for implanted biosensors . Cell‐release may occur either via a swelling or deswelling‐induced mechanism .…”

“…Thus, PNIPAAm hydrogels have been studied for thermally modulated cell‐release applications, including cell sheet tissue engineering, anti‐fouling coatings, and “self‐cleaning membranes” for implanted biosensors . Cell‐release may occur either via a swelling or deswelling‐induced mechanism . For instance, cell sheets cultured at 37 °C ( T > VPTT) were recovered without enzymatic digestion via swelling‐release by lowering the temperature below the VPTT .…”