Nanoscale tweezers for single-cell biopsies

Abstract

Much of the functionality of multi-cellular systems arises from the spatial organisation and dynamic behaviours within and between cells. Current single-cell genomic methods only provide a transcriptional "snapshot" of individual cells. The real-time analysis and perturbation of living cells would generate a step-change in single-cell analysis. Here we describe minimally invasive nanotweezers that can be spatially controlled to extract samples from living cells with singlemolecule precision. They consist of two closely spaced electrodes with gaps as small as 10-20 nm, which can be used for the dielectrophoretic trapping of DNA and proteins. Aside from trapping single molecules, we also extract nucleic acids for gene expression analysis from living cells, without affecting their viability. Finally, we report on the trapping, and extraction of a single mitochondrion. This work bridges the gap between single-molecule/organelle manipulation and cell biology and can ultimately enable a better understanding of living cells.

Active Particle Based Selective Transport and Release of Cell Organelles and Mechanical Probing of a Single Nucleus

“…In contrast to the commonly used fixed electrode geometry for DEP manipulation, our active particle [ 28 ] acts as a mobile microelectrode that can both manipulate (i.e., load and release) cargo using local DEP forces and transport cargo (through self‐propulsion), with/without directed motion (magnetic steering). Besides avoiding the need to fabricate electrodes, the inherent nanometric gap formed between the particle and the ITO‐coated glass substrate circumvents the need for complicated nanofabrication techniques, ensuring nanometric gaps between electrodes [ 19 ] when dielectrophoretically trapping nanoscale particle/biomolecules. This approach is particularly advantageous for trapping small organelles such as lysosomes.…”

“…Huang et al [ 18 ] proposed an optically‐induced cell lysis platform for nucleus extraction and collection. Nadappuram et al [ 19 ] designed and fabricated nanotweezers with two electrodes (gap: 20 nm) to trap mitochondria inside the neuron cell. Ashkin et al [ 20 ] manipulated mitochondria along microtubules using laser optical tweezing.…”

Plasmonic Tweezers towards Biomolecular and Biomedical Applications

“…Since PTs are based on conductive materials, electrophoresis (EP) [81] and dielectrophoresis (DEP) [82][83][84][85][86] can be applied to transport particles from the far field to the optical near field to feed PTs [87,88]. Using this combination, no extremely long waiting time is needed when extremely low concentration solutions are used.…”

ActuAtor, a molecular tool for generating force in living cells: Controlled deformation of intracellular structures

“…Physical probes include atomic force microscopy (Dufrêne et al, 2017), optical tweezers (Zhang and Liu, 2008), magnetic tweezers (Tanase et al, 2007; Sniadecki, 2010), pipette aspiration (Luo et al, 2013), micro- or nano-fabrication techniques such as patterned substrates (Nikkhah et al, 2012) and dielectrophoretic tweezers (Nadappuram et al, 2019). By being tractable and quantitative, these physical methods revealed a wide variety of cellular mechano-sensing mechanisms.…”