مقاله انگلیسی رایگان در مورد تحریک الکتریکی سلول ها از طریق آرایه های میکرو سلولی فتوولتائیک – الزویر ۲۰۱۸

Electrical stimulation may influence cell behavior associated with proliferation, differentiation, and migration, among others. The need for electrical tools to interact with living cells has pushed the technology to progressively develop less invasive devices. Technologies like energy harvesting have enabled wireless biological applications. Here we report the use of a photovoltaic microcell array (PVMA) based on silicon, as a wire-free interface to stimulate single cells with high spatial resolution. We demonstrate the effectivity of this microtool on osteoblast cells. The electrical stimulation triggered intracellular calcium transients as a response in 46% of the cells. The reduced dimension of the PVMA and its capacity to work in visible light show its potential for the wireless life science explorations.

Introduction

The possibility to modulate cell activity through electrical stimulation has become an interesting topic for cell research and the development of new therapeutic applications. There has been a wide exploration in this field, that goes from restoring or enhancing biological functions to preventing, for instance, loss of memory or muscular atrophy related to aging . In spite of this, many technological issues still need to be overcome in terms of spatial resolution, mechanical issues, and negative side effects such as the rejection of some electric probes. To address some of these problems, the tendency is to reduce the technology scale by enhancing spatial resolution and specificity, or even by developing highly flexible electrical probes. Furthermore, one alternative to overcome the limitations of the electrical stimulation is the energy harvesting technology . This technology obtains the energy directly from the environment and provides it in a wireless way . Energy harvesting devices make possible to explore the interactions of excitable cells with electric fields, as well as less invasive solutions to power autonomous biomedical devices. In terms of light harvesting, silicon-based photovoltaics have ruled the field due to their well-known efficiency, a favorable set of electrical and optical properties, their high natural abundance, their low cost and their biocompatibility . Furthermore, silicon-based devices rely on the existence of a mature and established infrastructure which allows a continuous dimension reduction . The conductivity of bare silicon can be increased linearly with illumination thanks to the charge carrier generation produced by the photoelectric effect. Taking into account the aforementioned optical properties of silicon, some researchers have stimulated single living cells using electrically polarized substrates and a light source focused on the selected cell . Nevertheless, this system was still dependent on many external factors, such as the voltage polarization. With the introduction of pn-junctions, it was possible to create controlled photovoltaic microstimulators with high spatial selectivity for applications like the replacement of the retina neurons or spinal cord stimulation in animal models. The evolution of the technology is headed towards reducing the size of the devices to restore cellto-cell communication in the less invasive way.