  Effective scaffolds for bone tissue-engineering are those that combine
adequate mechanical and chemical performance with osseointegrative,
angiogenetic and anti-bacterial modes of bioactivity. To address these
requirements via a combined approach, we additively manufactured square strut
scaffolds by robocasting precipitation-derived strontium/copper co-substituted
diopside. Microstructure, mechanical performance, bioactivity,
biocompatibility, and antibacterial activity were examined. The results show
that the presence of strontium and copper in the diopside lattice reduces the
grain size and increases the density of the ceramics. The compressive strength,
hardness, and fracture toughness of the diopside showed improvement, attributed
to a finer microstructure and improved sintering. Scaffolds had excellent
compressive strength with a high porosity (68 to 72 %), which is attributed to
the structure of the stacked square struts. All materials showed good in vitro
bioactivity and favorable proliferation of osteogenic sarcoma cells, while
strontium and copper co-doped materials exhibited the strongest
anti-Escherichia coli activity. We show that across multiple indicators this
system offers pathways towards high-performance bone substitutes.
