Additive Manufacturing of Biosilicate Glass-Ceramic Scaffolds for Advanced Bone Tissue Engineering Applications

In this thesis work, we will analyze the preparation, composition, mechanical and physical properties of glass-ceramic matrix composites for bone tissue regeneration. The objective is to produce Scaffolds with a high percentage of Biosilicate® porosity through Additive Manufacturing, in particular with a vat photopolymerization technique called Stereolithography, the first AM process to be patented and commercialized. The Biosilicate® fabrication process was carried out using the PDC (polymer-derived ceramics) technique, a synthesis process involving the controlled pyrolysis of polymeric precursors. Two types of mixtures were created using this technique, both characterized by the presence of the H44 (silicone precursor) and acrylate resin. In the emulsion we add the salts of calcium nitrate tetrahydrate, triturated sodium acetate and phosphoric acid; in the powder mixture instead we add calcium carbonate, sodium carbonate and sodium hydrogen phosphate. Following 3D Printing, the gyroids created with both mixtures were subjected to thermal treatments in air and nitrogen, and subsequently underwent compression tests to examine their mechanical response. Instead, to test the composition and thus confirm that the material was Biosilicate®, the scaffolds were analyzed using X-ray diffraction. The analysis allows the identification of the atomic structure by observing the crystalline phases developed following the thermal treatment.