Significant efforts are being made for control on axonal guidance due to its importance in nerve regeneration and in the
formation of functional neuronal circuitry in-vitro. These include several physical (topographic modification, optical
force, and electric field), chemical (surface functionalization cues) and hybrid (electro-chemical, photochemical etc)
methods. Here, we report comparison of the effect of linear flow versus microfluidic flow produced by an opticallydriven
micromotor in guiding retinal ganglion axons. A circularly polarized laser tweezers was used to hold, position and
spin birefringent calcite particle near growth cone, which in turn resulted in microfluidic flow. The flow rate and
resulting shear-force on axons could be controlled by a varying the power of the laser tweezers beam. The calcite
particles were placed separately in one chamber and single particle was transported through microfluidic channel to
another chamber containing the retina explant. In presence of flow, the turning of axons was found to strongly correlate
with the direction of flow. Turning angle as high as 90° was achieved. Optofluidic-manipulation can be applied to other types of mammalian neurons and also can be extended to stimulate mechano-sensing neurons.
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