Characterization of three-dimensional printed hydroxyapatite/collagen composite slurry

Nowadays, biomaterial composites for bone tissue engineering are developing rapidly. Many research studies have been done on hydroxyapatite (HA) and collagen because these materials are biomimetic and can be used in human bones. This study aimed to characterize a three-dimensional (3D) printed hydroxyapatite/collagen composite slurry material with a ratio of 99.84 % (w/v) and 0.16 % (w/v). The composite material was printed using 3D printing with a print speed of 10 mm/min and a layer height of 0.5 mm. Characterization layers were investigated using a scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX), and thermogravimetric analysis (TGA). SEM showed the occurrence of overlapping between layers, which was investigated by the reduction in layer dimensions after printing (layer size 432 μm). Moreover, there were no boundaries between layers; the connection between layers occurred, and porosity and the rough surface were presented. FTIR analyses showed spectrum peaks at 559.36, 628.79, 1022.27, 1562.34, and 1639.49 cm⁻¹ which was confirmed as hydroxyapatite and amide (indicates the presence of spectrum collagen). The XRD pattern peaks show the crystallinity of HA/collagen composite (41 %) and HA (42 %). The Ca/P ratio of the material composite was 1.77. The ratio was osteoconductive, and this characteristic was the main requirement for bone grafts. From TGA, the weight loss occurred between temperatures of 25 °C and 1000 °C with three stages: water absorption (1.844 %), removal of organic content (2.854 %), and decomposition of inorganic compounds (3.517 %).