Fig. 5

Compressive stress–strain curves of the HA nanocomposite hydrogels with ND-COOH or ND-OH at a pH 7 and b pH 8. c Gel breaking compressive peak force of the HA structures at pH 7 or 8 and surface functionalized NDs [HA without ND at pH 7 (red), pH 8 (blue)]. d Compressive peak force of HA structure without post-UV exposure (HA without ND at pH 7 (red), pH 8 (dark gray)