*2.9. Morphalogical Characteristics*

The field emission scanning electron microscope was used to analyse the morphological structures of the blue shark skin collagens (PSC and ASC). From the microphotography, both collagens were rich in a fibrillar network with many flaky orientation layers (Figure 6). The present finding was in accordance with the morphology of other fish collagens reported earlier [10,17]. However, the morphology was regular and an organized fibrillar network in PSC, while ASC had irregular fibrillar interconnectivity and wall morphology. It was opioned that the morphalogical features of collagen such as fibril interconnectivity, shape and wall morphology were important factors in tissue engineering, since they may influence the growth, migration, proliferation, differentiation, and maturation of cells [26]. In recent research, the collagen from the same species (blue shark skin) was used to formulate a scaffold 3D matrix and tested the proliferation and mineralisation effect on Saos-2 cells, and further confirmed that the scaffold prepared from blue shark skin collagen could support Saos-2 cell attachment and osteoblast-like cells formation [14]. In the present study, the morphological features confirmed the aptness of blue shark skin collagens in bone tissue engineering.

**Figure 6.** Morphological features of blue shark skin collagens using field emission scanning electron microscope. ASC-Acid soluble collagen, PSC-Pepsin soluble collagen. SEM image with 200 micro meter magnifications.
