Expression of integrin subunits on different functional-group-terminated surfaces.

Functional groups	Integrin	Outcomes	References
Methyl group, CH3	None	Maintain undifferentiated/quiescent state	65 and 66
Amine group, NH2	α5, αv and β1	Osteogenic differentiation	65–67
Carboxyl group, COOH	α5, β1, αv and β3	Chrondogenic differentiation	65 and 67
Hydroxyl group, OH	α5, αv and β1	Osteogenic and chrondogenic differentiation	66, 68–70
Phosphate group	αv and β1	Osteogenic differentiation	66