Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

Table 3 Covalent immobilization bioactive molecules to promote bone marrow mesenchymal stem cell adhesion, proliferation, and osteogenic differentiation

Bioactive molecules	Treatment process	Cell response	Ref.
Type I collagen	Titanium fiber meshes were treated with NaOH, followed by p-nitrophenyl chloroformate, and coated with collagen type I.	The modification of titanium fiber meshes can promote BMSC osteogenic differentiation.	van den Dolder et al[72]
	Covalent immobilization of collagen on titanium.	Greater regulation effect on BMSC osteogenesis compared to adsorptive immobilization.	Ao et al[74]
	Hyaluronic acid was immobilized on titanium surface by layer-by-layer technique.	BMSCs had more lamellipodia and adhered more closely to the covalently immobilized HyA surface.	Ao et al[78]
HyA	Covalent immobilization of RGD peptide on titanium surface.	RGD-functionalized titanium can improve early bone growth and matrix mineralization.	Elmengaard et al[87], Karaman et al[88]
RGD peptide	HBII-RGD was immobilized on the Ti surface.	HBII-RGD-functionalized Ti surfaces could stimulate BMSC differentiation and mineralization.	Guillem-Marti et al[90]
Growth factors	Covalently graft EGF and BMP-2 onto the oxide surfaces.	BMSC adhesion and proliferation were dramatically increased by covalently grafting EGF, but covalently grafted BMP-2 did not.	Bauer et al[92]
	PDGF-BB loading on titanium nanotube.	PDGF-BB functionalized surfaces significantly enhanced BMSC attachment and osteogenesis-related functions	Ma et al[98]

NaOH: Sodium hydroxide; BMSC: Bone marrow-derived mesenchymal stem cell; HyA: Hyaluronic acid; RGD: Arg-Gly-Asp; HBII-RGD: Heparin binding II-Arg-Gly-Asp; Ti: Titanium; EGF: Epidermal growth factor; BMP-2: Bone morphogenetic protein-2; PDGF-BB: Platelet-derived growth factor BB.