A good biocompatibility is the basic requirement of scaffolds employed in tissue engineering. To determine whether the SA/HNTs composite hydrogels are suitable for tissue engineering scaffolds, the cell adhesion and growth behavior were observed. Fig. 6(a) shows the fluorescent microscope images of the MC3T3-E1 cell after 72 h culture on the hydrogel samples. Cells can grow well on the control group (TCPS), indicating the good state of the used cells. In the hydrogel sample, both single cell and cell aggregates are found on the 3D hydrogel. Due to that the cells in the hydrogel are located in different depth, it is hard to focus all the cells in an image. No instinct cell morphology difference can be identified for the SA hydrogel and the composites hydrogel. Among the composite hydrogel, the SA1N1 sample shows much more cell number from the fluorescent microscope images. This may be attributed to the incorporation of proper content of HNTs leads to an increase in the cytocompatibility of SA.