Chronic Multi-Electrode Electromyography in Snakes

Knowledge about body motion kinematics and underlying muscle contraction dynamics usually derives from electromyographic (EMG) recordings. However, acquisition of such signals in snakes is challenging because electrodes either attached to or implanted beneath the skin may unintentionally be removed by force or friction caused from undulatory motion, thus severely impeding chronic EMG recordings. Here, we present a reliable method for stable subdermal implantation of up to eight bipolar electrodes above the target muscles. The mechanical stability of the inserted electrodes and the overnight coverage of the snake body with a “sleeping bag” ensured the recording of reliable and robust chronic EMG activity. The utility of the technique was verified by daily acquisition of high signal-to-noise activity from all target sites over four consecutive days during stimulus-evoked postural reactions in Amazon tree boas and Western diamondback rattlesnakes. The successful demonstration of the chronic recording suggests that this technique can improve acute experiments by enabling the collection of larger data sets from single individuals.

Biofabrication of controllable alginate hydrogel cell scaffolds based on bipolar electrochemistry

Bipolar electrochemistry successfully realized the electrodeposition of calcium alginate hydrogels in specific target areas in tissue engineering. However, the shape and quantity of three-dimensional cannot be accurately controlled. We presented a novel growth model for fabricating hydrogels based on bipolar electrochemical by patterned bipolar electrodes using photolithography. This work highlights pattern customization and quantitative control of hydrogels in cell culture platforms. Furthermore, alginate hydrogels with different heights can be controlled by adjusting the key parameters of the growth model. This strategy exhibits promising potential for cell-oriented scaffolds in tissue engineering.

Electric Field Induced Biomimetic Transmembrane Electron Transport using Carbon Nanotube Porins as Bipolar Electrodes

<p>Cells modulate their homeostasis through the control of redox reactions via transmembrane electron transport systems. These are largely mediated via oxidoreductase enzymes. Their use in biology has been linked to a host of systems including reprogramming for energy requirements in cancer. Consequently, our ability to modulate membrane redox systems may give rise to opportunities to modulate underlying biology. The current work aimed to develop a wireless bipolar electrochemical approach to form on-demand electron transfer across biological membranes. To achieve this goal, we show that using membrane inserted carbon nanotube porins that can act as bipolar nanoelectrodes, we could control electron flow with externally applied electric fields across membranes. Before this work, bipolar electrochemistry has been thought to require high applied voltages not compatible with biological systems. We show that bipolar electrochemical reaction via gold reduction at the nanotubes could be modulated at low cell-friendly voltages, providing an opportunity to use bipolar electrodes to control electron flux across membranes. Our observations present a new opportunity to use bipolar electrodes to alter cell behavior via wireless control of membrane electron transfer.</p>