Table 1.

Summary of research progress of hydrogel materials involved in this paper.

Polymer materials	Source	Composite hydrogel scaffold	Results	References
Gelatin	Natural	GHPA	The polymer can significantly induce the growth and differentiation of mesenchymal stem cell endothelial cells, and was also reported to reduce host macrophage activation	[12]
Gelatin	Natural	CG-CNPs	The scaffold not only exhibited superior physical, chemical, mechanical, and biological properties, but also significantly inhibited the growth of gram positive/negative bacteria, and the CG-CNP2 scaffolds are highly biocompatible, so it can be used to repair bone defects.	[14]
Collagen	Natural	rhCol	The scaffold not only good biological properties, but also improves the utilization rate of bFGF and promotes the repair of rat skull defects by continuously releasing bFGF	[20]
Collagen	Natural	CHCS	The scaffold not only exhibit increased mechanical strength, but have also been shown to accelerate the repair of bone defects by promoting collagen and new bone formation	[21]
Hyaluronic acid	Natural	HAP + HA1-ALG	HAP enhanced mechanical strength of composite hydrogel scaffold and the hydrogel system loaded with exosomes can significantly enhance bone regeneration.	[30]
Alginate	Natural	HAP/CS-ALG	As the content of HAP was increased, the porosity of the scaffold decreased, and in vivo experiments in mice revealed that the composite scaffold significantly promoted bone formation	[34]
Chitosan	Natural	MgFe-LDH nanosheet + chitosan/silk fibroin	This system not only enhanced the mechanical properties of the hydrogel, but also resulted in the release of PDGF and bone morphogenetic protein 2 (BMP-2) in turn promoting the regeneration of vascular cells and bone	[40]
Silk fibroin	Natural	SF@TA@HA2	The inorganic organic hybrid hydrogel not only significantly improved hydrogel performance, but also promoted bone defect regeneration in the early stage	[45]
Polyethylene glycol	Synthetic	PEG	Biologically active molecules can be functionalized and added to PEG hydrogel to simulate a natural ECM, improve cell vitality, and promote osteogenesis and/or cartilage generation	[49]
Polyvinyl alcohol	Synthetic	PVA + CS	This hydrogel has strong tensile strength, elongation at break and high compressive strength, and was shown to significantly accelerate the regeneration of rabbit bone defects	[53]
Polyvinyl alcohol	Synthetic	Na2B4O7+ PVA + AgNPs, +TEOS + pTi	This scaffold could not only promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, but also inhibited bacterial growth.	[54]
polylactic acid glycolic acid copolymer	Synthetic	PLGA	PLGA hydrogel provided a suitable environment for rat derived bone marrow stromal stem cells (rBMSCs). In addition, PLGA hydrogel containing LINC00473 modified rBMSCs could significantly promote bone repair and reconstruction of femoral head necrosis area.	[56]