A failure to observe enhanced diffusivity of glucose in a matrix of hyaluronic acid.

The diffusion coefficients for glucose and sucrose within matrices of hyaluronic acid are contrasted with coefficients determined in matrices of agarose. Diffusivity is similar in 0.5 and 1% matrices of both polysaccharide polymers dissolved in saline (0.9% NaCl solution) buffered at pH 7.4 with 0.01 M sodium phosphate. In a 2.5% matrix of hyaluronate, but not agarose, glucose diffusivity is enhanced 3-fold, whereas simultaneously determined sucrose diffusivity remains unchanged from that in the 1% matrix. The 1% hyaluronate matrix will enhance glucose diffusivity if an inorganic cationic serum constituent(s) with a molecular weight of less than 500 is incorporated into the solvent. This enhanced diffusivity is inversely dependent on glucose concentration and on the degree of polymerization of the hyaluronate in the matrix. The presence of an appropriately constituted matrix of hyaluronic acid endows the resultant fluid with several properties generally ascribed to membranes: permselectivity (even glucose and sucrose behave differently), saturability, and the potential to enhance translational movement of selected solutes such as glucose.