Protein Resistance of PNIPAAm Brushes: Application to Switchable Protein Adsorption

• Published in: Langmuir 2010-02, Vol.26 (3), p.1786-1795
• Main Authors: Burkert, Sina, Bittrich, Eva, Kuntzsch, Marco, Müller, Martin, Eichhorn, Klaus-Jochen, Bellmann, Cornelia, Uhlmann, Petra, Stamm, Manfred
• Format: Article
• Language: English
• Subjects: Acrylamides - chemistry; Acrylic Resins; Adsorption; Animals; Cattle; Chemical Phenomena; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Humans; Interfaces: Adsorption, Reactions, Films, Forces; Models, Molecular; Molecular Weight; Polymers - chemistry; Polyvinyls - chemistry; Protein Conformation; Proteins - chemistry; Serum Albumin - chemistry; Spectroscopy, Fourier Transform Infrared; Surface physical chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la902505q

Protein adsorption, as the primary process occurring when a foreign surface comes into contact with a biosystem, was studied on thin polymer brush films consisting of poly(N-isopropylacrylamide) (PNIPAAm) and poly(2-vinylpyridine) (P2VP). These films were prepared by the “grafting to” method. The protein resistance of stimuli responsive PNIPAAm-brushes toward serum albumin was recorded and compared with protein adsorption on P2VP brushes. To achieve a better understanding of protein resistance, PNIPAAm brushes with different molecular weights were investigated below and above the lower critical solution temperature of 32 °C. To use these findings for the adjustment and switching of protein adsorption, in a first attempt the adsorption on a mixed brush system consisting of PNIPAAm and P2VP chains was studied. This system showed temperature-dependent adsorption behavior due to the presence of PNIPAAm, representing a smart surface with stimuli-responsive changes in the physicochemical surface properties. With this mixed brush, the adsorbed amount of protein could be controlled, depending on composition and the temperature of the surroundings.