Table 2 Summary of example inorganic materials for bone regeneration

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]