abstract
- Additive manufacturing of calcium phosphate scaffolds has attracted growing attention for bone repair and localized drug delivery. Here we report the feasibility of printing monolithic structures by direct ink writing (DIW) using carbonate apatite powders obtained from bovine bone waste. Bone-derived powders were produced by thermal treatment at 850°C, milled below 149 µm, and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), and particle size distribution (PSD). To obtain printable inks without polymeric binders, water:glycol ratios were explored and a low fraction of silica nanoparticles was incorporated as a shape-fidelity modifier. XRD and FTIR confirmed the formation of B-type carbonate apatite, while SEM revealed aggregates of acicular nanoscale particles (¿ 100 nm). Stable DIW deposition was achieved mainly for the 70:30 (water:glycol) formulation containing 1 wt silica nanoparticles, using 0.41 - 0.51 mm nozzles. These preliminary monoliths provide a sustainable platform that can be further optimized and functionalized for post-printing drug loading aimed at local therapy.