Influence Of Poly(Acrylic Acid) Grafting Density On Switchable Protein Adsorption/Desorption Of Poly(2-Methyl-2-Oxazoline)/Poly(Acrylic Acid) Mixed Brushes

Poly(dopamine) is employed as an anchor to obtain a series of poly(acrylic acid) (PAA) and poly(2-methyl-2-oxazoline) (PMOXA) mixed brush coatings by sequential grafting to methods with PAA chains longer than PMOXA chains. Then, the prepared mixed brush coatings are rigorously characterized. The results show that the grafting density of PAA in mixed brushes could be well adjusted by changing the concentration of PAA solution used for the preparation of mixed brush coatings and the amounts of lysozyme adsorbed on PMOXA/PAA mixed brushes increase with increasing the grafting density of PAA chains while the desorption amounts decrease significantly when the grafting density of PAA is higher than one-half of PMOXA chains. When the grafting density of PAA is about one-half of PMOXA chains, the mixed brush could absorb high amounts of lysozyme (898.4 ng cm(-2)), and then more than 90% of adsorbed proteins could be released sharply by changing pH and ionic strength (I). (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48135.