Table 2.

Comparison of advantages and disadvantages of different regulation methods for cell behaviors.

Methods	Mechanisms	Advantages	Disadvantages
Surface topography modifying	Optimizing the surface topography of microchannels at nano-scale	•Inducing cell adhesion [156] •No other materials were introduced •High efficiency [157]	•Complex preparation processes [[158], [159], [160]] •High resolution and accuracy requirements [161]
Surface coating	Introducing other favorable materials on the surface of microchannels	•Inducing cell adhesion [162] •Accurate control •Significant changes in hydrophobicity [163]	Considered biocompatibility and degradation characteristics of materials [164]
External force applying	Changing the morphology of cells and stimulating secretion [165]	Improved proliferation, migration, differentiation and alignment of cells [166,167]	•Complex preparation processes •Indirectly determined forces [168]
Strain applying	Influencing the direction of cell growth and stimulating secretion [169]	Easily-controlling, improved alignment and differentiation of cells [[170], [171], [172]]	•Complex preparation processes •Thoughtful degradation characteristics
Medium Concentration changing	Modulating the speed of cell differentiation and reprogramming [173]	Controllable concentration gradient	Complex preparation and regulation processes
Surface microhardness changing	Inducing cell migration [174]	Controllable patterning [175] and no chemical components introduced	•Limited researches •Required quantitative analysis [176]
Biochemical cues adding	Inducing cell differentiation and reprogramming [177]	Synergistic regulation of multiple chemical factors	•Introducing other materials •Considerable biocompatibility
Light irradiating	Inducing cell proliferation and migration [178]	•No contact on cells •Killing bacteria [179]	•Limited materials •Required high-precision control [180]
Ultrasound exerting	Inducing cell proliferation and differentiation [181,182]	No contact on cells and no modify on scaffold surfaces	•Limited researches •Low-precision control [183]
Electricity stimulating	Activating intracellular signaling pathways, and influencing microenvironments [184]	Precise cellular regulation by the combination of specific materials/structures and electricity stimulating [185,186]	•Introducing conductive materials •Considerable biocompatibility
Magnetic stimulating	Enhanced intracellular delivery and changed cell stiffness [187]	No contact on cells and controlled matrixes for targeting cells [188]	•Limited researches •Introducing magnetic materials •Considerable biocompatibility