Scheme 1. (Left) Schematic Representation of the pH-Responsive Poly(cysteine methacrylate) (PCysMA) Brush Grown from a Planar Glass Surface and (Right) the POPC/DOTAP Lipid Binary Mixture Used to Form the Bilayer on the PCysMA Brush at pH 7.

The PCysMA brush (dry thickness = 5–8 nm) has a hydrated thickness of 15–24 nm below pH 3 and above pH 8. Between pH 3 and pH 8, the brush has an average thickness of 12 nm.