Fig. (5) Internal structure imaging and mechanical properties profiling of different g-n-HA content: A) Transmission electron microscopy images of unmodified n-HA; B) Transmission electron microscopy images of g1-n-HA; C) Mechanical properties (bending strength) of different g-n-HA content; D)) Mechanical properties (tensile strength) of different g-n-HA content (red curve is g1-n-HA, and black curve is g2-n-HA) [44].