Hyaluronic Acid Dictates Chondrocyte Morphology and Migration in Composite Gels

Tissue equivalent collagen-hyaluronic acid based hydrogels are widely used for cartilage tissue engineering, however not much importance has been given to investigate how cellular responses are altered with varying concentrations of hyaluronic acid in gels. In this study, different concentrations of hyaluronic acid dialdehyde (HAD) were combined with collagen to fabricate collagen-HAD composite (CH) gels, and the influence of HAD on cell shape, migration, viability, cytoskeletal organization and gel contraction were examined. The microstructure and the mechanical strength of the composite gels was altered by varying HAD concentrations. Morphology of chondrocytes cultured on CH gels showed significant increase in their aspect ratio and decrease in number of cell protrusions with increase in concentration of HAD. The organization of the cytoskeleton at the cellular protrusions were, vimentin localized at the base, microtubules at the tip and actin localized throughout the cell body. Changes in HAD concentra...