Biofabrication of glass scaffolds by 3D printing for tissue engineering

This paper reports a study on the development of bioactive glass powders for biofabrication of scaffolds by an additive manufacturing technique, three-dimensional printing (3DP). Several formulations of the glass were developed from the CaO·P2O5·TiO2 system and prepared on the basis of the results for the commercial powder characterization (average particle size, particle size distribution, microstructural and crystallographic analysis). For printing the glass models in the prototyping machine, a virtual model defined as the “standard model” was produced in commercial powder, and a systematic study of the relevant processing parameters (binder composition, formulation of powder, saturation level in the shell and core, bleed compensation, and printed layer thickness) was carried out in order to determine the most suitable conditions for the fabrication of porous structures for tissue engineering applications. The printed glass models were sintered through specific thermal programs and then characterized in terms of dimensions, structure, morphological features, and mechanical properties. Finally, the sintered models were submitted to mineralization tests in simulated physiological media. In this work, it was demonstrated that it is possible to use a printing machine to manufacture 3DP glassy porous structures with suitable features for tissue engineering applications as temporary scaffolds. The mechanical properties of the produced structures and its mineralization capability in physiological fluids suggest that they have potential to be used in bone tissue regeneration under low load-bearing situations.