Table 2.

Summary of example inorganic materials for bone regeneration

Category	Cement	Active principle	Main results	Refs.
Inorganic ions	CPC	Sr2+	Improve compressive strength and prolonging setting time Promote alkaline phosphatase activity and calcium nodule formation Upregulation of VFGF and Ang-1 expression	[86]
	CPC	Cu2+	Cu2+ ions (0.01–0.74 mg/mL) enhance compressive strength and injectability, while prolonging setting time The optimal concentrations (0.01–0.05 wt% CuP) promote osteogenesis and angiogenesis	[87]
	CPC	Li+	Li/CPC has favourable bioactivity in vitro to the same extent as that of CPC Lithium ions enhance biocompatibility and osteogenesis through activation of the Wnt/β-catenin signaling pathway	[89]
	CS/CPC	Zn2+/Sr2+	Adding two ions to bone cement can produce a synergistic effect Zn/Sr slightly prolongs the setting time of bone cement and has little effect on compressive strength Increase viability, adhesion, proliferation, and expression of osteoblast-related genes in osteoblast-related cells	[90]
	CPC	Si4+/Zn2+	Improve setting time, injectability and compressive strength Si/Zn dual elements switch macrophage polarity from the M1 phenotype into the M2 phenotype Enhance the osteogenic differentiation of BMSCs	[91]
Bioactive glasses	CPC	Mg2+/BG	2 Mg-BG-800-BC displays notably higher Mg ion release (0.41 ± 0.07 mg/L) BG-controlled Mg ion release significantly enhanced BMSCs migration and their secretion of bioactive molecules beneficial for bone regeneration BG-BC surface effectively modulated bone microenvironment via interactions with RAW264.7 and BMSCs	[99]
	CPC	Sr2+/MBG	MBG creates pores for tissue ingrowth and releases osteostimulative silicon ions through its controlled degradation Support better vascularization while facilitating the sustained release of strontium ions from the cement matrix	[101]
Other bioceramics	CPC	β-TCP	β-TCP particles (200–450 μm) can shorten the setting time and improve the mechanical strength of bone cement Formation of a tight bond between bone and CPC matrix after hydration	[107]
	CPC	Mn2+/β-TCP	Mn2+/β-TCP can enhance CPC surface properties (increased protein adsorption capacity and improved cellular response)	[108]
	PMMA	CS	CS can release Ca ions to promote the formation of hydroxyapatite Si ions released by CS can stimulate the proliferation and osteogenic differentiation of MSCs and promote angiogenesis Maintain similar compressive properties to pure PMMA while reducing setting times	[112]
	CPC	ZS/CS	The incorporation of ZS and CS into CPC induces the release of Zn, Ca and Si ions CS/ZS dual compound to CPC considerably enhance the osteogenic differentiation of stem cells	[113]