A Library of Tunable Agarose Carbomer-Based Hydrogels for Tissue Engineering Applications: The Role of Cross-Linkers

The role of the crosslinking agents was studied for a series of agarose-carbomer-based hydrogels, specifically developed for tissue engineering applications, and was quantified using the most typical polycondensation parameter; the ratio between the reacting moieties, i.e., hydroxyl (A) and carboxyl (B) groups. Because of the bonds among hydrophilic groups, as A/B ratio was increased, the gel network showed higher compactness and less ability to swell. The role of crosslinkers was also further analyzed using environmental scanning electron microscopy (E/SEM) and rheological measurements. SEM analysis underlined the presence of different structures as well as the erosion due to the presence of cosolvents in hydrogel synthesis. Rheological measurements showed the dependence of crossover strain value and yield stress upon the ratio of hydroxyl/carboxyl groups and, generally, a clear pseudoplastic behavior. Such detailed characterizations were essential to investigate the design of an optimized formulation capable of being a proper hosting environment for glial cells, which were here used as they are a promising cell type in several central nervous system repair strategies. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 2211-2221, 2012