Characterization of Fish Scale Derived Collagen-HAP Granule for Bone Repair

Objectives: Hydroxyapatite (HAP)-collagen composites are ideal bone substitutes since the components resembles the extracellular matrix of natural bone. For the substitutes, the collagen and HAP can be extracted and artificial synthesized through various methods, including direct blending, in situ precipitation, and biomimetic manner. To simplify the manufacture process, natural mineralized type I collagen with HAP, found in fish scales, are used as the potential biomaterials for bone graft development. In this study, the fish scale derived bone substitute granules (fsBSG) was manufactured and characterized in vitro and in vivo for bone repair.
Methods: fsBSG of diameter range from 0.425 to 1 mm were prepared and observed the geometry by SEM. The collagen and HAP properties were examined by hydroxyproline assay, SDS-PAGE, TGA thermal and XRD analysis. Biocompatibility of fsBSG was inspected based on ISO 10993-5. Moreover, the bone repair progress was studied on rabbit radius defect model filled w/o fsBSGs for 8 and 12 weeks by using X-ray and histological staining.
Results: The fsBSG particles showed irregular and rougher morphology. Collagen of type I was identified with content of 31.3 %. The HAP content was 53.6 % and also characterized by XRD pattern comparing with JCPDS standard. There was no significant cytotoxicity on fsBSG. At the fsBSG implant region, the mineralization was detected with higher signal on X-ray image, which was evidenced by the dense matrix formation and angiogenesis through the repair progression.
Conclusions: This study showed the first time to prepare bone substitute granule from natural fish scale. The major composition of designed fsBSG was characterized with the proportion similar with bone. The in vivo results revealed that fsBSG has the potential to be applied in bone repair.