CLSM was further used to characterize the cell morphology on the hydrogels. Fig. 6 (c) shows the CLSM images of cells cultured on SA,SA2N1, and SA1N1 for 3 day. The nuclei and cytoplasm were stained into blue and red colorwith DAPI and phalloidin-TRITC respectively. Consistent with the fluorescent microscope result, all the hydrogels can support
the MC3T3-E1 cells growth. The cells on the composite hydrogel surfaces exhibit diffuse cytoskeleton and well-stretched actin bundle,also the small pseudopodia stretched out obviously with one or more foot processes. In contrast, the cells cultured on pure SA hydrogel show an elongated shape with little thin filopodia and filaments. The total adhesive
area of cells cultured on the composite hydrogel surfaces is clearly higher than that of cultured on pure SA hydrogel, suggesting the improved cytocompatibility of the composites. The addition of other nanoparticles also can lead to the improved cytocomaptibiltiy of polymers [56,57].