Extracellular electrophysiological based sensor to monitor cancer cells cooperative migration and cell-cell connections

Perspective-Assessing Electrochemical, Aptamer-Based Sensors for Dynamic Monitoring of Cellular Signaling

Electrochemical, aptamer-based (E-AB) sensors provide a generalizable strategy to quantitatively detect a variety of targets including small molecules and proteins. The key signaling attributes of E-AB sensors (sensitivity, selectivity, specificity, and reagentless and dynamic sensing ability) make them well suited to monitor dynamic processes in complex environments. A key bioanalytical challenge that could benefit from the detection capabilities of E-AB sensors is that of cell signaling, which involves the release of molecular messengers into the extracellular space. Here, we provide a perspective on why E-AB sensors are suited for this measurement, sensor requirements, and pioneering examples of cellular signaling measurements.

Integration of electrotaxis and durotaxis in cancer cells: Subtle nonlinear responses to electromechanical coupling cues

Cells in living organisms live in multiphysics-coupled environments. There is growing evidence indicating that both exogenous electric field (EEF) and extracellular stiffness gradient (ESG) can regulate directional movement of cells, which are known as electrotaxis and durotaxis, respectively. How single cells respond to the ubiquitous electromechanical coupling cues, however, remains mysterious. Using microfluidic chip-based methodology and finite element-based electromechanical coupling design strategies, we develope an electromechanical coupling microchip system, enabling us to quantitatively investigate polarization and directional migration governed by EEF and ESG at the single cell level. It is revealed that both of electrotaxis and durotaxis nonlinearly depend on the physiological EEF and ESG, respectively. Specific combinations of EEF and ESG can subtly modify the polarization states of single cells and thus induce hyperpolarization and depolarization. Cells can integrate electrotaxis and durotaxis in response to multi-cue microenvironments via subtle mechanisms involving cooperation and competition during cellular electrosensing and mechanosensing. The work offers a platform for quantifying migration and polarization of cells driven by electromechanical cues, which is essential not only for elucidating physiological and pathological processes like embryo development, and invasion and metastasis of cancer cells, but for manipulating cell behaviors in a controllable and programmable fashion.

A host-coupling bio-nanogenerator for electrically stimulated osteogenesis

Implantable self-powered generators (ISPGs) have been extensively explored as energy supplies for driving electronics and electrically stimulated therapeutics in vivo. However, some drawbacks arise, such as complicated architectonics, inescapability of wire connection, energy instability, and consumption. In this study, a host-coupling bio-nanogenerator (HCBG) is developed to configure a self-powered regional electrical environment for powerful bone regeneration. An HCBG consists of a porous electret nanofiber mat coupled with interstitial fluid and stimulated objects of the host after implantation, forming a host coupling effect. This bio-nanogenerator not only overcomes the disadvantages of general ISPGs, but also accomplishes both biomechanical energy scavenging and electrical stimulation therapeutics. The enhancement of osteogenesis differentiation of bone marrow mesenchymal stem cells in vitro and bone regeneration in vivo are remarkably achieved. Moreover, osteogenic ability is systematically evaluated by regulating the electrical performance of HCBGs. Osteogenic differentiation is activated by upregulating more cytosolic calcium ion, following to activate the calcium ion-induced osteogenic signal pathway, while applying electrical stimulation. As an implantable medical technology, the HCBG provides an explorative insight to facilitate the development of ISPG-based electrical medical therapeutics.