Bidirectional transport of kinesin or dynein-coated microspheres on polar oriented microtubules

Artificial nanotransport inspired by intracellular transport processes has been investigated for over a decade using the motor protein kinesin and microtubules to achieve unidirectional cargo transport. Here, we demonstrate simultaneous bidirectional nanotransport of microspheres by integrating the oppositely directed motor proteins, kinesin and dynein, with an oriented microtubule track. Our statistical analysis demonstrates that 87-98% of microspheres move in the designated direction at mean velocity 0.22-0.26 mum/s (kinesin-coated microspheres) and 0.34-0.39 mum/s (dynein-coated microspheres).