Nanoparticle-Mediated Visualization and Control of Cellular Membrane Potential: Strategies, Progress, and Remaining Issues.

The interfacing of nanoparticle (NP) materials with cells, tissues, and organisms for a range of applications including imaging, sensing, and drug delivery continues at a rampant pace. An emerging theme in this area is the use of NPs and nanostructured surfaces for the imaging and/or control of cellular membrane potential (MP). Given the important role that MP plays in cellular biology, both in normal physiology and disease, new materials and methods are continually being developed to probe the activity of electrically excitable cells such as neurons and muscle cells. In this Review, we highlight the current state of the art for both the visualization and control of MP using traditional materials and techniques, discuss the advantageous features of NPs for performing these functions, and present recent examples from the literature of how NP materials have been implemented for the visualization and control of the activity of electrically excitable cells. We conclude with a forward-looking perspective of how we expect to see this field progress in the near term and further into the future.