3D-printed silicate porous bioceramics using a non-sacrificial preceramic polymer binder

Abstract

Silicate bioceramics possess an excellent bioactivity; however, shaping them into complex geometries is still challenging. Therefore, this paper aims to present a new strategy for the shaping of a bioglass-ceramic with controlled geometry and properties starting from a glass powder combined with a preceramic polymer, i.e. a silicon resin, and reactive fillers. The powder-based three-dimensional (3D)-printing of wollastonite (CaSiO3)-based silicate bioceramic parts was demonstrated in this work. The resin plays a dual role, as it not only acts as a non-sacrificial binder for the filler powders in the printing process but it also reacts with the fillers to generate the desired bioceramic phases. The mechanical and physical properties, i.e. ball-on-three-balls test, density, porosity and morphology, were evaluated in 3D-printed discs. These samples possessed a total porosity around 64 vol% and a biaxial flexural strength around 6 MPa. The raw materials used in this work also enabled the 3D-printing of scaffolds possessing a designed multi-scale porosity, suitable bioceramic phase assemblage and a compressive strength of 1 MPa (for cylindrical scaffolds with total porosity ~80 vol%). Solubility in TRIS/HCl and in vitro assays, i.e. viability, cytotoxicity and apoptosis assays, were also performed. In vitro tests indicated good cell viability and no cytotoxicity effect on the cells.

Additive Manufacturing of Ceramics: Issues, Potentialities, and Opportunities

“…The resulting ceramic part after heat treatment still had a similar level of residual porosity, as the material does not sinter during the process. Moreover, the preceramic polymer can be used as a nonsacrificial, reactive binder mixed with a glass powder to create bioceramic scaffolds based on wollastonite‐apatite …”

Biosilicate® scaffolds produced by 3D‐printing and direct foaming using preceramic polymers

“…Silica, resulting from the thermo‐oxidative decomposition of silicones, easily reacts with the oxides provided by the fillers (consisting of carbonates, hydroxides or oxides). Several bioactive crystalline Ca‐based silicate ceramics, according to this process, have been produced and belong to the vast range of “polymer‐derived ceramics” (PDC), known for their distinctive shaping possibilities, through direct foaming, extrusion, and additive manufacturing, available before heat treatment (in the polymer state) …”

3D printed porous β-Ca2SiO4 scaffolds derived from preceramic resin and their physicochemical and biological properties

“…In the past several years, 3D printing technique has been widely used in fabricating biomaterials for bone tissue engineering combined with polymer-derived technique [33–41]. In this way, Bernardo et al [37–39] prepared 3D wollastonite-based scaffolds from preceramic polymers. Calcium carbonate and commercial available silicone were selected as active filler and silicon source, respectively.…”