CMOS microcavity arrays for single-cell electroporation and lysis

Area of Science:

• Biotechnology
• Microfluidics
• Cell Biology

Background:

• Transfection is crucial for single-cell analyses.
• Reversible electroporation (EP) is a common transfection method requiring precise electric field control.
• Existing microelectrode arrays lack effective electroporation capabilities due to planar electrode design.

Purpose of the Study:

• To develop an integrated single-cell analysis platform with enhanced electroporation capabilities.
• To demonstrate controlled electroporation for cell transfection using a novel on-chip system.
• To validate cell viability post-electroporation.

Main Methods:

• Utilized a commercial complementary metal-oxide-semiconductor (CMOS) process to create microcavities with 3D-aligned electrodes.
• Employed deep-reactive ion etching with the CMOS metal stack as an etch mask.
• Performed electroporation on human embryonic kidney cells (HEK-293) using Calcein as a model, varying electric field intensities.

Main Results:

• Demonstrated the first on-CMOS controlled electroporation for transfection.
• Observed increased Calcein leaching with higher electric fields, followed by reuptake, confirming cell viability.
• Numerical simulations of pore density showed good agreement with experimental results.

Conclusions:

• The developed 3D electrode microcavity system enables precise control of electroporation on-chip.
• This technology is suitable for effective single-cell transfection and analysis with integrated feedback.
• Advances single-cell analysis platforms by overcoming limitations of planar electrode designs.