Hierarchical macroporous material with dual responsive copolymer brushes and phenylboronic acid ligands for bioseparation of proteins and living cells

The formation of a hybrid composite material consisted of polymer brushes and phenylboronic acid ligands on a macroporous cryogel is reported here for the first time for effective adsorption of glycoprotein and yeast cells. The surface area of the cryogel was increased by covalent immobilization of silica nanoparticles. Random co-polymer brushes composed of N-isopropylacrylamide and glycidyl methacrylate were grown on the surface of the nanoparticles using surface-initiated atom transfer radical polymerization. Boronic acid ligands were attached to the polymer brush via Cu(I)-catalysed azide-alkyne cycloaddition click reaction. Due to the macro-porosity of the final affinity material, particulate-containing fluids can pass through the composite cryogel at a high flow rate with almost no back pressure. An affinity column packed with the composite cryogel was tested to evaluate the capability of selective protein and cell separation. Glycated haemoglobin and yeast cells were successfully separated from a complex protein mixture and from a wastewater sample, respectively. The dynamic binding capacity of the column was found to be 63.9 and 6 mg/g gel for haemoglobin and yeast cells, respectively.