Pinpoint Delivery of Molecules by Using Electron Beam Addressing Virtual Cathode Display

Area of Science:

• Biotechnology
• Cell Biology
• Nanotechnology

Background:

• Electroporation is a physical method for introducing molecules into cells.
• Microelectrode devices can implement electroporation for localized effects.
• Existing methods face challenges in achieving fine, high-speed control.

Purpose of the Study:

• To develop a novel method for precise, localized transmembrane molecular delivery.
• To investigate the use of a virtual cathode generated on a silicon nitride membrane for electroporation.
• To assess the efficacy and safety of this technique for cell transfection.

Main Methods:

• Fabrication of a virtual cathode pattern on a 100-nm-thick SiN membrane using inverted-electron beam lithography.
• Application of the virtual cathode to induce localized electroporation on C2C12 myoblast cells in culture medium.
• Delivery of fluorescent dye (propidium iodide) and monitoring of intracellular fluorescence.
• Assessment of cell viability using time-lapse imaging.

Main Results:

• Successful generation of a localized negative charge and electric current on the SiN membrane surface.
• Demonstration of localized transmembrane molecular delivery into C2C12 cells at the virtual cathode position.
• Correlation of molecular inflow with beam duration and acceleration voltage.
• Evidence of membrane recovery and sustained cell viability after the procedure.

Conclusions:

• The virtual cathode technique enables precise, localized electroporation and molecular delivery.
• This method offers a promising approach for targeted cell transfection with high viability.
• The SiN membrane effectively functions as a vacuum barrier and virtual cathode display.