Analytical ultracentrifugation to support the development of biomaterials and biomedical devices.

Analytical ultracentrifugation (AUC) primarily serves to investigate hydrodynamic and thermodynamic properties of natural and synthetic macromolecules and colloids in solution, dispersion or suspension. Beside such more conventional use, AUC can support materials development particularly by combining different optical systems, if the AUC is equipped with such, or using complementary data evaluation approaches. In this context, an Optima XL-I equipped with absorbance (AO) and interference optics (IO) was used alone or complementary to study the success of conjugation of biopolymers, to evaluate the completeness of the incorporation of macromolecules into micelles and vesicles, and to analyze the composition and homogeneity of macromolecular assemblies. The combination of AO and IO proved covalent binding of concanavalin A to dextran without macromolecular degradation as well as the formation of mixed micelles composed of two types of block copolymers. Further, AUC contributed to analyze the homogeneity, purity, size and size distribution of carbon monoxide-releasing macromolecular assemblies. These case studies revealed that the application possibilities of AUC are by far not completely discovered but can still be extended.