Table 4.

Representative examples of ion substituted bioceramics in bone tissue engineering

Ceramic-based materials	Ion elements	Post-treatment	Effect	Printing parameters	Ref.
BG	Mo	1350°C, 3 h	BG scaffolds with Mo incorporation enhanced the mechanical strength, and stimulated bioactivities of BMSCs. The release of ${\text{MoO}}_4^2$- could promote chondrogenesis by activating HIF-α pathways and restrained catabolic responses by regulating TIMP3, MMP13 and ADAMTS5	Pressure: 1.5–3.0 bar Printing speed: 5 mm/s	[264]
β-TCP	Ag	1100°C, 3 h	Ag@GO nano composite-modified scaffolds were not only effective in killing bacteria, but also had positive effects on osteogenesis by promoting the expression of an osteoblast-related gene in BMSCs.	Pressure: 3 MPa Nozzle diameter: 0.52 mm Step distance: 1.11 mm	[270]
BG	Cu	1300°C, 3 h	Cu2+ facilitated the proliferation and maturation of chondrocytes through activating HIF pathway, and further promoting the anti-inflammatory M2 phenotype and elevating the secretion of anti-inflammatory cytokines in macrophages to reduce the damage of cartilage tissue.	Pressure: 3–6 bar Printing speed: 6 mm/s Nozzle diameter: 0.22 mm	[265]
β-TCP	Mg/Si	1250°C, 2 h	Significantly higher bone and blood vessel formation were observed for the TCP scaffolds with Mg and Si in rat distal femoral defect model.	Not report	[266]
β-TCP	Fe/Si	1250°C, 2 h	The presence of Fe and Si improved mechanical strength of β-TCP scaffolds after sintering, as well as exhibiting an enhanced early-stage osteoconduction and neovascularization in vivo.	pure β-TCP layers: 35 μm Doped β-TCP layers: 35 μm	[267]
BG	Cu/Fe/Mn/Co	1300°C, 3 h	Photothermal performance: Cu > Fe > Mn > Co Cu–BG, Fe–BG and Mn–BG scaffolds effectively killed tumor cells in vitro and significantly inhibited tumor growth in vivo	Not report	[271]
Ca–Si	Sr/Mg	1150°C, 45 min 1150°C, 3 h	Compared with conventional β-TCP scaffold, Sr/Mg/Ca–Si scaffolds had better apatite formation ability and bone induction performance.	Printing speed: 6 mm/s Nozzle diameter: 450 μm Filament spacing: 850 μm	[259]
MBG/AlgMC	Zn	CaCl2 crosslinking, 10 mins	The addition of Zn in BMG/AlgMC ink greatly reduced viscosity.	Nozzle diameter: 410 μm Printing width: 7.75 mm Strand distance: 1.8 mm	[268]
HA/MC	Sr	Glutaraldehyde crosslinking	Sr-HA scaffolds with mineralized collagen improved cell adhesion and proliferation in vitro, and exhibited more bone formation in bone defect.	Pressure: 0.25–0.5 MPa Nozzle diameter: 0.4 mm Filament spacing: 1.1 mm Printing speed: 5–8 mm/s	[262]
MBG	Sr	No	3D printed Sr-MBG scaffolds exhibit good apatite-forming bioactivity and sustained drug delivery properties, facilitating cell proliferation and differentiation	Printing speed: 9–12 mm/s Nozzle diameter: 0.4 mm Pressure: 1.5–3.8 bar	[231]
Ca–Si/PCL	Mg/Sr	No	3D-printed Mg-/Sr-doped Ca–Si-based scaffold stimulated bone regeneration via dual-stimulation of AKT and WNT signaling pathways	Pressure: 200–250 kPa	[269]

AlgMC, alginate-methylcellulose; MC, mineralized collagen.