Building programmable multicompartment artificial cells incorporating remotely activated protein channels using microfluidics and acoustic levitation

Abstract

Intracellular compartments are functional units that support the metabolism within living cells, through spatiotemporal regulation of chemical reactions and biological processes. Consequently, as a step forward in the bottom-up creation of artificial cells, building analogous intracellular architectures is essential for the expansion of cell-mimicking functionality. Herein, we report the development of a droplet laboratory platform to engineer complex emulsion-based, multicompartment artificial cells, using microfluidics and acoustic levitation. Such levitated models provide free-standing, dynamic, definable droplet networks for the compartmentalisation of chemical species. Equally, they can be remotely operated with pneumatic, heating, and magnetic elements for post-processing, including the incorporation of membrane proteins; alpha-hemolysin; and mechanosensitive channel of large-conductance. The assembly of droplet networks is three-dimensionally patterned with fluidic input configurations determining droplet contents and connectivity, whilst acoustic manipulation can be harnessed to reconfigure the droplet network in situ. The mechanosensitive channel can be repeatedly activated and deactivated in the levitated artificial cell by the application of acoustic and magnetic fields to modulate membrane tension on demand. This offers possibilities beyond one-time chemically mediated activation to provide repeated, non-contact, control of membrane protein function. Collectively, this expands our growing capability to program and operate increasingly sophisticated artificial cells as life-like materials.

Recent Advances in Microfluidic Technologies for the Construction of Artificial Cells

“…[175] To mimic the signaling across membranes, Barrow et al used microfluidics and acoustic levitation to develop programmable artificial cells with remotely activated protein channels (Figure 13A). [176] They successfully reconstituted alpha-hemolysin and MscL membrane proteins to direct Ca 2+ ion transport across the levitated compartmentalized droplet network. The gating of MscL channels can be selectively and repeatedly controlled through an external magnetic field and a levitating acoustic field, allowing for the induction of channel opening by perturbing membrane tension.…”

“…Reproduced with permission. [ 176 ] Copyright 2022, Springer Nature. B) Division of artificial cells based on a microfluidic platform.…”

Artificial cells eavesdropping on HepG2 cells

“…Artificial cells (ACs) aim to mimic structural and functional features of mammalian cells or bacteria. The complexity of a living cell can be divided into its essential cellular hallmarks [1], such as compartmentalization [2][3][4], multicellular organization [5], energy generation [6,7], division [8], information processing and cellular communication [9,10]. ACs often aim to mimic a specific cellular hallmark rather than trying to imitate the entire complexity of the cellular machinery, resulting in simplified, synthetic models.…”

Effective Cell Transfection in An Ultrasonically Levitated Droplet for Sustainable Technology

“…Droplet‐based microfluidics with acoustic levitation has been applied for the study of liquid marble coalescence, [ 5 ] fabrication of the nanoparticle self‐assembly using an air−water interface, [ 6 ] and bottom‐up creation of artificial cells. [ 7 ] In the field of microreactions, the use of levitated droplets for chemical reactions, such as click chemistry, [ 8 ] alkaline phosphatase hydrolysis, [ 9 ] peroxidase‐catalyzed colorimetric reactions, [ 8 ] and restriction enzyme digestion [ 8 ] has been reported. Additionally, this technology has been applied in analytical studies of biological samples including Raman spectroscopy of red blood cells and malaria‐infected cells, [ 10 ] atmospheric pressure chemical ionization mass spectrometry, [ 11 ] and structural analysis of apoferritin using synchrotron small‐angle X‐ray scattering.…”