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Melikov, R.

Publications and source records attributed to Melikov, R..

2 recordsLinked to original sources

High-frequency extracellular spiking in electrically-active cancer cells

Microelectrode matrices have been extensively used in the past 30 years as a reliable platform to record the extracellular activity of cells traditionally regarded to as excitable, i.e. brain cells and muscle cells. Meanwhile, fundamental biology studies on cancer cells since the 1970s reveal that they exhibit altered functionalities of ion channels, membrane potentials, metabolism, and communication mechanisms when compared to their healthy counterparts. In this work, we present for the first time the presence of extracellular voltage spikes occurring at high frequencies (0.1-3.5 kHz) in breast cancer cells, resembling the ones observed in excitable cells, and the possibility to record them with 30 {micro}m TiN microelectrode matrices. These preliminary findings may open a new path for exploration in a variety of research fields, enabling the access to bioelectrical dynamics in cancer cells and cell networks, targeting bioelectricity as a tool in anticancer drug development and cancer diagnostics, as well as provide a market expansion for companies commercializing microelectrodes and microelectrode recording systems.

bioengineering↗

Plasmon-Coupled Photocapacitor Neuromodulators

Efficient transduction of optical energy to bioelectrical stimuli is an important goal for effective communication with biological systems. For that plasmonics has significant potential via boosting the light-matter interactions. However, plasmonics has been primarily used for heat-induced cell stimulation due to membrane capacitance change (i.e., optocapacitance). Instead, here we demonstrate that plasmonic coupling to photocapacitor biointerfaces improves safe and efficacious neuromodulating displacement charges for an average of 185% in the entire visible spectrum while maintaining the Faradaic currents below 1%. Hot-electron injection dominantly leads the enhancement of displacement current at blue spectral window, and nanoantenna effect is mainly responsible for the improvement at red-spectral region. The plasmonic photocapacitor facilitates wireless modulation of single cells at 3-orders of magnitude below the maximum retinal intensity levels corresponding to one of the most sensitive optoelectronic neural interfaces. This study introduces a new way of using plasmonics for safe and effective photostimulation of neurons and paves the way toward ultra-sensitive plasmon-assisted neurostimulation devices.

biophysics↗