Table 2.

Characteristics and functions of Mg-enriched injectable hydrogels.

Materials	Characteristic	Experiments	Animal Model	Functions	Author/ Year
Struvite Composite Cell-Laden Hydrogel	elastic modulus: approximately 7.26 × 103 Pa	in vitro	-	GelMA: has fluidity, stability, and degradability Composite: promotes osteogenesis and angiogenesis	Liu, C./2021 [121]
Chitin-PBSu hydrogel system with 2%MBG and 2%FNPs	elastic modulus: approximately 1.45 × 105 Pa	in vitro	-	chitin-PBSu hydrogel: mimics the ECM; provides cues for the surrounding cells to proliferate; helps in healing the defect site FNPs: enhances the cell attachment and spreading; angiogenic property MBG: promotes higher protein adsorption for helping in better cell attachment and spreading; possess osteoinductive and angiogenic properties	Vishnu Priya, M./2016 [120]
SAG hydrogel	the pore size ranged of freeze-dried porous scaffolds from 150 to 250 μm	in vivo	maxillary sinus floor elevation in rabbits	promotes bone formation via CXCR4 elevation and ERK signaling pathway	Zhang, X./2018 [100]
injectable macroporous hydrogels	void ratio 73.04 ± 5.92%	in vivo	SD rat femur defects model	Mg-degradation-dependent H2-foaming method directly generated pores in cell-laden hydrogels while sustaining the injectability and cytocompatibility of the hydrogels	Tang, Y./2020 [123]

Note: GelMA: Gelatin methacrylate; PBSu: poly (butylene succinate); ECM: extracellular matrix; FNP: fibrin nanoparticles; MBG: magnesium-doped bioglass; CXCR4: C-X-C chemokine receptor type 4; ERK: extracellular regulated protein kinases; SD: Sprague Dawley.