Direct ink writing of silica-bonded calcite scaffolds from preceramic polymers and fillers

Abstract

Silica-bonded calcite scaffolds have been successfully 3D-printed by direct ink writing, starting from a paste comprising a silicone polymer and calcite powders, calibrated in order to match a SiO/CaCO weight balance of 35/65. The scaffolds, fabricated with two slightly different geometries, were first cross-linked at 350 °C, then fired at 600 °C, in air. The low temperature adopted for the conversion of the polymer into amorphous silica, by thermo-oxidative decomposition, prevented the decomposition of calcite. The obtained silica-bonded calcite scaffolds featured open porosity of about 56%-64% and compressive strength of about 2.9-5.5 MPa, depending on the geometry. Dissolution studies in SBF and preliminary cell culture tests, with bone marrow stromal cells, confirmed the in vitro bioactivity of the scaffolds and their biocompatibility. The seeded cells were found to be alive, well anchored and spread on the samples surface. The new silica-calcite composites are expected to be suitable candidates as tissue-engineering 3D scaffolds for regeneration of cancellous bone defects.

The Impact of Bioceramic Scaffolds on Bone Regeneration in Preclinical In Vivo Studies: A Systematic Review

“…Among various bioceramics, calcium phosphates, such as hydroxyapatite (HA) and tricalcium phosphate (TCP), are commonly used bone grafting materials due to their resemblance to the bone mineral phase [10,11]. Besides calcium phosphate ceramics, more recently a new class of biomaterials, known as silicate bioceramics, have received significant attention for hard tissue regeneration [12][13][14][15].…”

3D printed porous β-Ca2SiO4scaffolds derived from preceramic resin and their physicochemical and biological properties

“…Moreover, the addition of bioactive glass could control the solubility in Tris-HCl buffer, and the mechanical strength was around 6 MPa with a high porosity of 80%. Similarly, Fiocco et al [40] fabricated silica-bonded calcite scaffolds by direct ink writing, starting from a paste comprising a silicone resin and calcite powders. The fabricated silica-bonded calcite scaffolds had open porosity of 56–64% and compressive strength of 2.9–5.5 MPa, depending on the geometry.…”

Organosilicon polymer-derived ceramics: An overview

“…Silicate ceramics are often used as cements, concrete, bioceramics, etc. [18,[90][91][92][164][165][166][167][168][169][170]. Among them, calcium-based silicate ceramics have been developed for biomedical applications due to their excellent bioactivity [171][172][173].…”

“…During sintering, CaO reacted with silica to form wollastonite phase while hydroapatite was inert. Fiocco et al [92] fabricated CaCO 3 /SiO 2 composite bioceramics. Here, CaCO 3 powers were used as inert fillers and SiO 2 was derived from polysiloxane sintering at 600 ℃.…”