3D Bio-Plotted Tricalcium Phosphate/Zirconia Composite Scaffolds to Heal Large Size Bone Defects

β-TCP-Zirconia scaffolds with different architectures were fabricated by means of 3D-Bioplotting in order to enhance the mechanical and in-vitro ability of the scaffold to heal large size bone defects. In the present study scaffold architecture with different strand orientations (0°-90°, 0°-45°-135°-180°, 0°-108°-216° and 0°-72°-144°-36°-108°) were fabricated, characterized and evaluated for mechanical strength and cell proliferation ability. β-TCP powder (25 µm) and PVA (Polyvinyl Alcohol) was acquired from Fisher Scientific, India. Zirconia (18 to 32 µm) was procured from Lobachemie, India. In brief 7.5%, PVA in distilled water was used as a binder and was mixed with 10 grams of (70/30) TCP-Zirconia ratio to make the ceramic paste. The paste was further sieved through a 100-micron sieve and was filled in a 30 ml syringe. With 400 microns needle, the scaffold architectures were printed layer by layer and were allowed to dry at room temperature. The dried samples were sintered at 1500oC in a silicon carbide furnace and were allowed to remain at this temperature for 5 hours. The sintered samples were then characterized by X-Ray Diffraction, Scanning Electron Microscopy, Uniaxial Compression Tests, Fourier transform infrared spectroscopy and cell proliferation by XTT assay using MG-63 human osteosarcoma cell line. It was revealed that all samples maintained their structure and functional groups after sintering. Also, it was found that the architecture with (0°-72°-144°-36°-108°) strand orientation had the best strength and cell proliferation ability. Jointly these properties are required for scaffold fabrication in the field of bone tissue engineering

3D Bio-Plotted Composite Scaffold Made of Collagen Treated Hydroxyapatite-Tricalciumphosphate for Rabbit Tibia Bone Regeneration

Biphasic calcium phosphate scaffolds with 20/80 HA/TCP ratio were fabricated using the 3D-Bioplotting system to heal critical size defects in rabbit tibia bone. Four different architectures were printed in a layer by layer fashion with lay down patterns viz. (a) 0°– 90°, (b) 0°– 45°– 90°– 135°, (c) 0°–108°– 216° and (d) 0°– 60°– 120°. After high-temperature sintering scaffolds were coated with collagen and were further characterized by (FTIR) Fourier Transform Infrared Spectroscopy, (SEM) Scanning Electron Microscopy, (XRD) X-Ray diffraction, Porosity analysis and Mechanical testing. Scaffold samples were tested for its ability to induce cytotoxicity in Balb/c 3T3 cells at in vitro condition using elution method. Skin sensitization potential of scaffolds was evaluated in male guinea pigs using guinea pig maximization test (GPMT). Further, scaffolds were implanted in eight rabbit tibia bones and biocompatibility and histological evaluations were carried out after 4 and 8 weeks implantation periods. In-vitro results include bonding, surface morphology, phases, porosity, mechanical strength and Cytotoxicity. In-vivo results include sensitization, capsule formation, inflammation, presence of polymorphonuclear cells, giant cells, plasma cells, X-Rays and degradation of the material. It was concluded that HA/TCP/Collagen scaffold with 0°– 45°– 90°– 135° architecture exhibits the most excellent properties in healing critical size bone defects in rabbits