Physicochemical properties of aqueous mixed solutions of sugar-persubstituted poly(amidoamine)dendrimers and bovine serum albumin

The interactions of bovine serum albumin (BSA) with sugar-persubstituted poly(amidoamine)dendrimers (SB, generation 3 and 5) have been studied using several techniques including interfacial rheometer. The sample solutions are prepared by mixing SB5 or SB3 to BSA under a fixed concentration of BSA. In BSA–SB5 system, mixed solutions become turbid due to the formation of aggregates between BSA and SB5 by adding a small amount of SB5, but a further addition of SB5 renders the aggregates redispersed. These results are reflected in the changes of surface tension, interfacial rheology, and circular dichroism (CD) spectra for BSA–SB5 system. On the other hand, BSA–SB3 system does not show significant physicochemical properties due to a weak interaction between BSA and SB3.