Synthesis and Characterization Properties of Gelatin-Fluorhydroxyapatite Composite Scaffold for Application in Bone Tissue Engineering and Investigation of Cellular Attachment

Bone injuries are among the challenges of medical science that each year has high costs for treatment in the world. Fluorhydroxyapatite plays an important role in promoting the integration of bones and dental implants, increasing bone density and calcium levels, and accelerating the recovery of bone fractures. In this study, fluorhydroxyapatite powder and composite scaffolds with different weight percentages (40, 50, and 60) of fluorhydroxyapatite were fabricated through co-precipitation and freeze drying mechanisms, respectively. In order to investigate the microscopic properties of composite scaffolds, scanning electron microscopy was used. Also, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy tests were used to evaluate the purity of the manufactured specimens. In addition, in order to evaluate the biological properties of composite scaffolds, MTT and alkaline phosphatase (ALP) tests were used, and finally, the strength of scaffolds and the rate of water absorption were studied. Data analysis was performed using one-way analysis of variance. Microscopic investigations indicated a porous microstructure with pore diameters within the range of 100-350 μm, which is acceptable for osteoblastic cells to grow and proliferate. Also, the results of FTIR and XRD confirmed the absence of impurities in the samples. In addition, the non-toxicity of the produced specimens and the proper functioning of the bone cells were confirmed through MTT assay (after 3 and 7 days) and ALP activity (after 3, 7, and 14 days), respectively. Accordingly, the scaffold with 60 wt% of fluorhydroxyapatite showed more biocompatibility and ALP activity than the other two scaffolds. Also, the average of Young's modulus and yield strength for the samples were 40 and 7 MPa, which are acceptable for use in bone tissue engineering. The results showed that the application of fluorhydroxyapatite with gelatin not only improves biological properties but also improves the mechanical properties of the scaffold. Additionally, the obtained results emphasized the potential use of prepared scaffolds to repair bone tissue.