Positive and negative chemotaxis of enzyme-coated liposome motors


The ability of cells or cell components to move in response to chemical signals is critical for the survival of living systems. This motion arises from harnessing free energy from enzymatic catalysis. Artificial model protocells derived from phospholipids and other amphiphiles have been made and their enzymatic-driven motion has been observed. However, control of directionality based on chemical cues (chemotaxis) has been difficult to achieve. Here we show both positive or negative chemotaxis of liposomal protocells. The protocells move autonomously by interacting with concentration gradients of either substrates or products in enzyme catalysis, or Hofmeister salts. We hypothesize that the propulsion mechanism is based on the interplay between enzyme-catalysis-induced positive chemotaxis and solute–phospholipid-based negative chemotaxis. Controlling the extent and direction of chemotaxis holds considerable potential for designing cell mimics and delivery vehicles that can reconfigure their motion in response to environmental conditions.

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Fig. 1: Schematic illustration of liposomes in the gradients and the experimental set-up.
Fig. 2: Catalysis-induced positive chemotaxis of catalase-coated liposomes and negative chemotaxis of urease-coated liposomes.
Fig. 3: Reconfiguration of direction of movement in ATPase-bound liposomes.
Fig. 4: Ruling out electrolyte diffusiophoretic transport.
Fig. 5: Ruling out density-driven transport.
Fig. 6: Chemotactic movement of inactive liposomes in glucose.

Data availability

The data that support the findings of this study are available from A.Sen upon reasonable request.


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The work was supported by the Center for Chemical Innovation funded by the National Science Foundation (grant no. CHE-1740630). P.S.C. and D.V. acknowledge the National Science foundation for funding their work (grant nos. CHE-1709735 and CBET-1603716, respectively)

Author information




The work was conceived by P.S.C., D.V. and A.Sen. A.Somasundar, S.G., F.M., L.N.M. and T.Y. performed the experiments. F.M. carried out the modelling. All the authors contributed to the discussion of results and the writing of the manuscript.

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Correspondence to Paul S. Cremer or Darrell Velegol or Ayusman Sen.

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Somasundar, A., Ghosh, S., Mohajerani, F. et al. Positive and negative chemotaxis of enzyme-coated liposome motors. Nat. Nanotechnol. 14, 1129–1134 (2019). https://doi.org/10.1038/s41565-019-0578-8

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