Table 1.

Maintenance of stemness using biophysical and biochemical stimulations.

Type of stimulation	Details of condition	Type of cells	Observation	Ref.
Biophysical stimulation	Low-intensity pulsed ultrasound (LIPUS)	hMSCs	hMSCs differentiated into chondrocyte without dedifferentiation in nonchondrogenic differentiation environments.	[18]
	LIPUS	hMSCs	The transplanted cells differentiated into chondrocytes and regenerated defect sites of recipient cartilage.	[19]
	Ultrasound	hMSCs	Ultrasound treatment enhanced fracture healing by promoting osteogenic differentiation of hMSCs.	[20]
	Fluid flow	Osteocyte, osteoblast, and hMSCs	Flow stimulation promoted recruitment, proliferation, and differentiation of osteoprogenitor cells.	[21]
Overexpression of genetical factor	SRY- (sex-determining region Y-) box 2 (SOX2) Sirtuin 1 (SIRT1)	hMSCs	Overexpression of Sox2 enhanced stemness of MSCs during in vitro cultivation.	[23]
		hMSC	Overexpression of SirT1 prevented age-associated senescence of MSCs via Sox2 regulation.	[26, 27]
	Octamer-binding transcription factor 4 (Oct4) or pron. nanOg (Nanog)	hMSC	Viral transfection of Oct4 or Nanog enhanced the self-renewal and differentiation potential of MSCs.	[24, 25]
Treatment of organic compound	Resveratrol	hMSCs	Resveratrol treatment enhanced maintenance of the self-renewal and differentiation capacity of MSCs during ex vivo cultivation.	[28]
	Nuclear factor erythroid-derived 2-like 2 (NRF2)	hMSCs	Treatment of t-BHQ, the activator of NRF2, promoted self-renewal ability and osteogenic differentiation via inhibition of p53 expression.	[35]