Summary of key data for each guanidinium modified PAMAM dendrimer salt, demonstrating their physical properties and their interaction with aCgn.

MW-molecular weight, Vo-partial molar volume at infinite dilution, [3]-molar concentration of the additive, D-Dendrimer, A-Anion, and P-Protein. Partial molar volume was determined from density measurements of gravimetrically prepared dendrimer only solutions. Preferential interactions (Γ23) with aCgn were determined by VPO, aCgn denaturation midpoint temperature (Tm) increments were determined by DSC, and the number of hydrogen bonds between different species were determined from MD simulations. aCgn solutions for the Γ23 (50 mg/mL) and Tm (1 mg/mL) data contained 20 mM sodium citrate pH 5 buffer and a maximum dendrimer concentration of 0.2 mol/L.