Drycells: Cell‐Suspension Micro Liquid Marbles for Single‐Cell Picking

Abstract

Cell-picking technology is essential for cell culturing. Although the recently developed tools enable single-cell-level picking, they rely on special skills or additional devices. In this work, a dry powder that encapsulates single to several cells with a >95% aqueous culture medium, thereby acting as a powerful cell-picking tool, is reported. The proposed "drycells" are formed by spraying a cell suspension onto a powder bed of hydrophobic fumed silica nanoparticles. The particles adsorb to the droplet surface and form a superhydrophobic shell, which prevents the drycells from coalescence. The number of encapsulated cells per drycell can be controlled by adjusting the drycell size and cell-suspension concentration. Moreover, it is possible to encapsulate a pair of normal or cancerous cells and create several cell colonies within a single drycell. A sieving process can be used to sort the drycells according to size. The size of the droplet can range from one to hundreds of micrometers. The drycells are sufficiently stiff to be collected using tweezers; however, centrifugation separates them into nanoparticles and cell-suspension layers, with the separated particles being recyclable. Various handling techniques, such as splitting coalescence and inner liquid replacement, can be used. It is believed that the application of the proposed drycells will greatly improve the accessibility and productivity of single-cell analysis.

Liquid marbles: review of recent progress in physical properties, formation techniques, and lab-in-a-marble applications in microreactors and biosensors

“…4I–K illustrate different approaches used to shape LMs. 13,113,114 The first method, presented in Fig. 4I, reported a box-shaped droplet covered with a millimetric star-shaped plate.…”

“…4K shows a bottom-up shaping approach through the formation of non-spherical LMs by merging micro-LMs as building blocks. 13 This method enables the fabrication of complex marbles with micrometric dimensions, such as microfiber-shaped LMs formed by the coalescence of a micro-LM line. These new concepts are expected to give rise to unexpected LM properties, systems, and applications.…”

“…9,10 The outer particles of LMs are repeatedly used owing to the low wettability between the particles and the inner liquid (recyclable). 11–13 The easy recyclability of outer particles and lossless inner liquid transportation make LMs a promising technology for achieving a circular economy. Hence, the physical properties of LMs, such as multilevel robustness based on the application environment, have been intensively studied.…”

Universality of Scaling Laws Governing Contact and Spreading Time Spans of Bouncing Liquid Marbles and its Physical Origin

“…32−36 Several biological applications of liquid marbles were reported. 33,34 In particular, the use of liquid marbles as microfluidic devices and micromixers was demonstrated. 35,36 Various techniques enabling fabrication of liquid marbles including noncontact and electrostatic manufacturing were described.…”

“…Our work is devoted to the study of the bouncing of liquid marbles, first introduced in the pioneering paper by Quéré et al. − Liquid marbles (LMs) are droplets coated with colloidal particles enabling separation of the liquid within from the solid substrate by an air layer. − This separation gives rise to the high mobility of liquid marbles, thus representing an alternative to the lotus-like-inspired superhydrophobicity . Properties and applications of liquid marbles were studied intensively in the last decade. − Several biological applications of liquid marbles were reported. , In particular, the use of liquid marbles as microfluidic devices and micromixers was demonstrated. , Various techniques enabling fabrication of liquid marbles including noncontact and electrostatic manufacturing were described. , It should be mentioned that liquid marbles are separated from the solid substrate with air cushions, thus resembling the wetting regime inherent for superhydrophobic surfaces. − , Our present paper is focused on universal laws describing bouncing liquid marbles on solid substrates. The impact of liquid marbles with soap films was studied in ref .…”