Diffusion of Linear Polymers in Hyaluronate Solutions

Abstract

The diffusion through hyaluronate solutions of six linear polymer fractions with molecular weights between 31000 and 530000 has been investigated. The polymers (sodium deoxyribonucleate. polyadenylate, polyvinyl hydrogen phthalate and polyanethol sulfonate) absorb ultraviolet light and their diffusion could therefore be registered in synthetic boundary cells in the analytical centrifuge with the aid of a photoelectric scanning system, without interference from the hyaluronate. The presence of hyaluronate retarded the diffusion of the polymers. The data could be fitted to a relatinship for the retardation of globular particles in polymer netweorks described by Laurent, Björk, Pietruszkiewicz, and Persson (1963), which has recently been supported by theoretical work of Ogston, Preston, and Wells (1973). The linear polymers were, however, less retarded in the hyaluronate network than globular particles of equal hydrodynamic dimensions. The results suggest that asymmetric particles and coiled molecules preferentially penetrate the network by end-on movements as this offers fewer obstacles in their path than a random movement of whole hydrodynamic units. For a rigid rod this could lead to a unidimensional diffusion in the polymer network.