Engineering of Biocompatible Coacervate-Based Synthetic Cells

Abstract

Polymer-stabilized complex coacervate microdroplets have emerged as a robust platform for synthetic cell research. Their unique core–shell properties enable the sequestration of high concentrations of biologically relevant macromolecules and their subsequent release through the semipermeable membrane. These unique properties render the synthetic cell platform highly suitable for a range of biomedical applications, as long as its biocompatibility upon interaction with biological cells is ensured. The purpose of this study is to investigate how the structure and formulation of these coacervate-based synthetic cells impact the viability of several different cell lines. Through careful examination of the individual synthetic cell components, it became evident that the presence of free polycation and membrane-forming polymer had to be prevented to ensure cell viability. After closely examining the structure–toxicity relationship, a set of conditions could be found whereby no detrimental effects were observed, when the artificial cells were cocultured with RAW264.7 cells. This opens up a range of possibilities to use this modular system for biomedical applications and creates design rules for the next generation of coacervate-based, biomedically relevant particles.

Functional Interactions Between Bottom‐Up Synthetic Cells and Living Matter for Biomedical Applications

“…However, an inherent strength of all synthetic cells is that we know exactly what is contained within them, thanks to their bottom‐up design, and can undertake a component‐based approach to investigate the cytotoxicity of individual components. We have recently reported such a systematic approach, which clarified exactly which component caused cytotoxic effects, and enabled us to modulate the formulation of the synthetic cells to make them biocompatible [73] . Secondly, many of these synthetic cell systems utilize the same biological machinery, such as the aforementioned quorum sensing pathways and GOX to produce hydrogen peroxide in situ.…”

Connecting primitive phase separation to biotechnology, synthetic biology, and engineering

“…As such, the incorporation of phase separation processes into artificial cell construction has not yet been explored to the full potential, despite the existence and importance of intracellular phase separation. Nevertheless, a number of very recent studies have utilized membraneless compartments generated from phase separation as artificial cell models (Martin 2019;Shang and Zhao 2021;van Stevendaal MHME et al 2021).…”

Programmable Zwitterionic Droplets as Biomolecular Sorters and Model of Membraneless Organelles

“…A few relevant examples, among many others, are poly( N ‐isopropylacrylamide) (PNIPAM), peptide polymers, and simple and complex coacervates. [ 17–24 ]…”

“…A few relevant examples, among many others, are poly(N-isopropylacrylamide) (PNIPAM), peptide polymers, and simple and complex coacervates. [17][18][19][20][21][22][23][24] In addition to stimulus-responsiveness, recent biological studies have shown that different protein LCDs are capable of modulating emerging properties of the compartments, such as viscosity, polarity, and the partitioning of different client molecules. [25][26][27] These results demonstrate that the architecture of the scaffold component can control not only the stimulusresponsiveness but also several mesoscopic properties of the resulting compartments, which in turn are crucial for modulating the biochemical processes within them.…”