A Comparison of Bioactive Glass Scaffolds Fabricated by Robocasting from Powders Made by Sol-Gel and Melt-Quenching Methods

authors	Ben-Arfa, BAE; Pullar, RC
nationality	International
journal	PROCESSES
author keywords	robocasting; bioactive glass; scaffold; sol-gel; biomaterials; biomedical implants
keywords	MECHANICAL-PROPERTIES; PHOSPHATE SCAFFOLDS; MICROSTRUCTURE; CERAMICS; BEHAVIOR; SYSTEM
abstract	Bioactive glass scaffolds are used in bone and tissue biomedical implants, and there is great interest in their fabrication by additive manufacturing/3D printing techniques, such as robocasting. Scaffolds need to be macroporous with voids >= 100 mu m to allow cell growth and vascularization, biocompatible and bioactive, with mechanical properties matching the host tissue (cancellous bone for bone implants), and able to dissolve/resorb over time. Most bioactive glasses are based on silica to form the glass network, with calcium and phosphorous content for new bone growth, and a glass modifier such as sodium, the best known being 45S5 Bioglass(R). 45S5 scaffolds were first robocast in 2013 from melt-quenched glass powder. Sol-gel-synthesized bioactive glasses have potential advantages over melt-produced glasses (e.g., greater porosity and bioactivity), but until recently were never robocast as scaffolds, due to inherent problems, until 2019 when high-silica-content sol-gel bioactive glasses (HSSGG) were robocast for the first time. In this review, we look at the sintering, porosity, bioactivity, biocompatibility, and mechanical properties of robocast sol-gel bioactive glass scaffolds and compare them to the reported results for robocast melt-quench-synthesized 45S5 Bioglass(R)scaffolds. The discussion includes formulation of the printing paste/ink and the effects of variations in scaffold morphology and inorganic additives/dopants.
publisher	MDPI
isbn	2227-9717
year published	2020
volume	8
issue	5
digital object identifier (doi)	10.3390/pr8050615
web of science category	Engineering, Chemical
subject category	Engineering
unique article identifier	WOS:000541752600038