Table 2.

Some examples of the modification of the cells in treatment.

Cell type	Modification	Reference
NP-derived mesenchymal stem cell (NPMSC)	Cell pretreatment by simvastatin	Ref. [44]
Adipose-derived stem cell (ADSC)	Cell injection with microsphere loaded with dexamethasone and growth factor	Ref. [63]
Bone marrow-derived mesenchymal stem cell (BMSC)	Cell pretreatment by TGF-1	Ref. [64]
Mesenchymal stem cell (MSC)	Coculture with nucleus pulposus cells	Ref. [65]
NP-differentiated mesenchymal stem cell	Hypoxic culture environment	Ref. [66]
Adipose-derived stem cell (ADSC)	Cell pretreatment by LiCl	Ref. [67]
Mesenchymal stem cell	Cell pretreatment by hyaluronic acid (HA) and platelet-rich plasma (PRP)	Ref. [68]