Structural, mechanical and osmotic properties of injectable hyaluronan-based composite hydrogels

The osmotic and scattering properties of hyaluronan-based composite hydrogels composed of stiff biopolymer chains (carboxymethylated thiolated hyaluronan (CMHA-S)) crosslinked by a flexible polymer (polyethylene glycol diacrylate (PEGDA)) are investigated and analyzed in terms of the scaling theory The total pre-gel polymer weight concentration is varied between 0 5 wt.% and 3 2 wt %, while the mole ratio between the reactive PEG chain ends and the thiolated HA moieties is changed between 015 and 1 0. The shear modulus G of the fully-swollen gels exhibits a stronger dependence on pre-gel concentration than on the crosslink density. Osmotic deswelling measurements reveal that the osmotic mixing pressure depends on the weight ratio CMHA-S/PEGDA, and is practically unaffected by the pre-gel concentration Small-angle neutron scattering observations indicate that the thermodynamic properties of these composite gels are governed by total polymer concentration, i e., specific interactions between the two polymeric components do not play a significant role (C) 2010 Elsevier Ltd. All rights reserved