Mobile Silk Fibroin Electrode for Manipulation and Electrical Stimulation of Adherent Cells

Abstract

Microfabricated mobile electrodes, nanopallets, designed to provide adherent cells with electrical stimulation are reported. Nanopallets composed of a cross‐linked silk fibroin hydrogel matrix incorporated with poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are used. The silk fibroin composite is characterized not only by mechanical and electrical conductive properties, but also by its optical transparency in both the visible and ultraviolet regions, and by its biocompatibility with adherent cells. It is demonstrated that the adherent cells, including normal cell‐lined cells and primary neuronal cells, loaded on the nanopallets can be manipulated while faithfully retaining their adhesive properties. By applying voltages via the nanopallets, the voltage‐dependent calcium channels expressed in the cells are selectively stimulated, and this is confirmed by using confocal fluorescent microscopy during manipulation and performing multiangle observations. These features are attributed to both the mobile operation of the transparent nanopallets, and the ability to simultaneously measure electrical signals and perform fluorescent observations.

Cell Assembly in Self-foldable Multi-layered Soft Micro-rolls

“…1a , Supplementary Fig. S1 ), Ca-alginate and silk fibroin were spin-coated on a SiO 2 substrate and gelated using both methanol treatment and water-annealing processes in accordance with previously reported protocols 41 – 43 . Then, the tops of the films were laminated with parylene-C layer by chemical vapour deposition (CVD).…”

“…Then, the tops of the films were laminated with parylene-C layer by chemical vapour deposition (CVD). Thereafter, the multi-layered film was micro-patterned photolithographically, and etched with oxygen plasma through a photoresist mask, resulting in highly defined geometries 28 , 33 , 41 , 44 . SEM images showed clearly identifiable trilaminar films (Fig.…”

Organic Electrochemical Transistors (OECTs) Toward Flexible and Wearable Bioelectronics

“…A good example of this is conducting polymer hydrogels in which the conductive polymer is embedded in a hydrophilic cross-linked polymer matrix. The resultant material combines the electroactivity of the PEDOT with the mechanical properties of the nonconductive polymer [ 60 , 61 , 62 , 63 ].…”

Fabrication of Graphene Microroll Aptasensor

“…In recent years, it has become possible to use microfabrication techniques for the manipulation of individual cells, enabling the investigation of the expression level and localization of excreted substances, while controlling the behavior and morphology of target cells. (1)(2)(3) However, it is still difficult to perform the quantitative analysis of the substances secreted and released from the cells across the cell membrane at the single-cell level because of their diffusive nature after secretion. If an accurate quantitative analysis of extracellular secreted substances becomes possible, it will lead to a better understanding of cellular responses to changes in their external environment.…”