Figure 1.

Schematic illustration represents the experimental design for dynamic compression experiments. (a) The alkyl-hydrazone (green) crosslink equilibrium leads to more viscoelastic material properties (e.g., faster stress relaxation) than the more stable benzyl-hydrazone (purple) crosslinks. (b) The viscoelastic properties of hydrazone CANs are varied based on the molar percentage of alkyl-hydrazone versus benzyl-hydrazone crosslinks. (c) Articular chondrocytes were encapsulated in hydrazone hydrogels and allowed three days to recover from isolation and encapsulation stresses. (d) On Day 3, Chondrocyte-laden hydrazone hydrogels were transferred to dynamic compression bioreactors which were programed to apply a cyclic 15% strain at a rate of 1 Hz for one hour each day. Dynamically loaded hydrogels were compared to free swelling controls 3, 10, 17, 24 and 31 days after encapsulation.