Label-Free Targeted High Efficiency Electroporation with Single-Cell Feedback Control Using Focused Microscale Electric Fields

Efficient, safe, and cell-selective intracellular delivery remains a bottleneck for scalable and cost-effective manufacturing of cell therapies. Here, we introduce Selective Permeabilization using Impedance Cytometry (SPICy) that couples multifrequency single-cell impedance cytometry with real-time, feedback-controlled, low-voltage single-cell electroporation. Electric field focusing in a 3-D printed biconical micro-aperture confines both sensing and electroporation to a microscale zone, enabling continuous-flow operation and the use of low voltages (<15 V) for electroporation. Impedance spectra are captured for each single cell and machine-learning based analysis enabled accurately distinguishing cells in a label-free manner. Selectively triggered low-voltage electroporation achieved simultaneous high delivery efficiency (>80 %) and high (>90 %) cell viability. Delivery of a range of different cargo sizes (4-500 kDa), GFP mRNA expression, CRISPR-Cas9 based knock-out and delivery to a variety of different cell lines, primary human T cells and peripheral blood mononuclear cells (PBMCs) was also demonstrated. Using heterogenous or mixed samples, selective delivery to both cell lines, and primary immune cell subpopulations, from PBMCs, was demonstrated. SPICy thus provides a label-free, continuous flow, targeted non-viral platform for precision cell engineering.