3D Printed Biosilicate Scaffolds From Preceramic Polymers and Fillers


Giorgia Franchin


Giorgia Franchin (1) Andrea Zocca (1) Paolo Colombo (1,2)

Author Affiliation: 

(1) Department of Industrial Engineering, University of Padova, Padova, Italy (2) Department of Materials Science and Engineering, The Pennsylvania State University, USA


The aim of this work was to fabricate highly porous, open cell biosilicate scaffolds for bone tissue engineering applications by direct 3D printing using a preceramic polymer and both active and passive fillers. Biosilicate ceramics were obtained starting from mixtures of a silicone polymer and oxide precursors as active fillers, which were later converted into a ceramic material upon thermal treatment at 1200°C in different atmospheres. The use of preceramic polymers as starting materials allowed to directly 3D print scaffolds with an extrusion-based additive manufacturing machine. Optimization of the printing paste in terms of homogeneity and rheological properties allowed to achieve full control of filament size, spacing, nature and extent of the porosity. The final components, after drying, pyrolysis and sintering, showed that the sintered surface is uniform and the structure possessed a regular pore size of about 0.4 mm; the sintered filaments welded perfectly to each other, and did not deform during both printing and sintering. Scaffolds treated in air produced pure hardystonite networks with a compressive strength of 1.6±0.3MPa and a total porosity of 75.0±2%vol. Sparse cracks were present, due to the exothermal oxidation of the silicone polymer when heated in air. Cracks were completely absent from the scaffolds treated in nitrogen, leading to an increased compressive strength of 2.5±0.5MPa and a total porosity of 78.8±2%vol. Heating in nitrogen led to wollastonite as the main phase. Both kind of scaffolds seemed to be suitable for applications as bone grafts: biological characterization is currently being carried out.