Poly(2-substituted-2-oxazoline) surfaces for dermal fibroblasts adhesion and detachment

The thermoresponsive surfaces of brush structure (linear polymer chains tethered on the surface) based on poly(2-isopropyl-2-oxazoline)s and copolymers of 2-ethyl-2-oxazoline and 2-nonyl-2-oxazoline were obtained using the grafting-to method. The living oxazoline (co)polymers have been synthesized by cationic ring-opening polymerization and subsequently terminated by the reactive amine groups present on the surface. The changes in the surface morphology, philicity and thickness occurring during surface modification were monitored via atomic force microscopy, contact angle and ellipsometry. The thickness of the (co)poly(2-substituted-2-oxazoline) layers ranged from 4 to 11 nm depending on the molar mass of immobilized polymer and reversibly varied with the temperature changes. This confirmed thermoresponsive properties of obtained surfaces. The obtained polymer surfaces were used as a support for dermal fibroblast culture and detachment. The fibroblasts' adhesion and proliferation on the polymer surfaces were observed when the culture temperature was above the cloud point temperature of the immobilized polymer. Lowering the temperature resulted in the detachment of the dermal fibroblast sheets from the polymer layers, which makes these surfaces suitable for the treatment of wounds and in skin tissue engineering.