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Designing artificial cells to harness the biological ion concentration gradient

Abstract

Cell membranes contain numerous nanoscale conductors in the form of ion channels and ion pumps1,2,3,4 that work together to form ion concentration gradients across the membrane to trigger the release of an action potential1,5. It seems natural to ask if artificial cells can be built to use ion transport as effectively as natural cells. Here we report a mathematical calculation of the conversion of ion concentration gradients into action potentials across different nanoscale conductors in a model electrogenic cell (electrocyte) of an electric eel. Using the parameters extracted from the numerical model, we designed an artificial cell based on an optimized selection of conductors. The resulting cell is similar to the electrocyte but has higher power output density and greater energy conversion efficiency. We suggest methods for producing these artificial cells that could potentially be used to power medical implants and other tiny devices.

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Figure 1: Anatomy of the electric eel and structure of the natural electrocyte.
Figure 2: Schematic diagram of a system of electrogenic cells used in the simulations, and subsequent action potential formation.
Figure 3: A comparison of action potentials formed in the electrocyte, artificial cell and pseudo squid giant axon.
Figure 4: A comparison of action potentials formed in the electrocyte, artificial cell and pseudo squid giant axon.

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Acknowledgements

We thank F. Sigworth, E. Jakobsson, S. Natarajan, J. Novotny, T.P. Ma and S. Yulke for their discussions and comments. The full description of the procedures used in this paper requires the identification of certain software and operating systems and their suppliers. The inclusion of such information should in no way be construed as indicating that such software or operating systems are endorsed by NIST or are recommended by NIST or that it is necessarily the best software or operating system for the purposes described. This work is supported by the National Centre for Design of Biomimetic Nanoconductors, funded by grant no. PHS 2 PN2 EY016570B from the National Institutes of Health through the NIH Roadmap for Medical Research.

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J.X. and D.A.L. conceived and designed the experiments. J.X. performed the experiments. J.X. and D.A.L. analysed the data and co-wrote the paper.

Corresponding author

Correspondence to David A. Lavan.

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Xu, J., Lavan, D. Designing artificial cells to harness the biological ion concentration gradient. Nature Nanotech 3, 666–670 (2008). https://doi.org/10.1038/nnano.2008.274

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