Extinction spectroscopy and particle size analysis of PSN solutions before and after addition of MDM2. (A and B) Extinction profiles (A) and particle size distributions (B) of PSN-12.1 (i) and PSN-12.1WΔA (ii) samples without MDM2 (black) and 96 h after addition of 300 (dotted gray), 500 (short dashed gray), 1,000 (long dashed gray), and 2,000 (solid gray) MDM2 monomers per PSN.