Synthetic Biology: A Bridge between Artificial and Natural Cells.

Artificial cells are simple cell-like entities that possess certain properties of natural cells. In general, artificial cells are constructed using three parts: (1) biological membranes that serve as protective barriers, while allowing communication between the cells and the environment; (2) transcription and translation machinery that synthesize proteins based on genetic sequences; and (3) genetic modules that control the dynamics of the whole cell. Artificial cells are minimal and well-defined systems that can be more easily engineered and controlled when compared to natural cells. Artificial cells can be used as biomimetic systems to study and understand natural dynamics of cells with minimal interference from cellular complexity. However, there remain significant gaps between artificial and natural cells. How much information can we encode into artificial cells? What is the minimal number of factors that are necessary to achieve robust functioning of artificial cells? Can artificial cells communicate with their environments efficiently? Can artificial cells replicate, divide or even evolve? Here, we review synthetic biological methods that could shrink the gaps between artificial and natural cells. The closure of these gaps will lead to advancement in synthetic biology, cellular biology and biomedical applications

Construction of membrane-bound artificial cells using microfluidics: a new frontier in bottom-up synthetic biology

The quest to construct artificial cells from the bottom-up using simple building blocks has received much attention over recent decades and is one of the grand challenges in synthetic biology. Cell mimics that are encapsulated by lipid membranes are a particularly powerful class of artificial cells due to their biocompatibility and the ability to reconstitute biological machinery within them. One of the key obstacles in the field centres on the following: how can membrane-based artificial cells be generated in a controlled way and in high-throughput? In particular, how can they be constructed to have precisely defined parameters including size, biomolecular composition and spatial organization? Microfluidic generation strategies have proved instrumental in addressing these questions. This article will outline some of the major principles underpinning membrane-based artificial cells and their construction using microfluidics, and will detail some recent landmarks that have been achieved

Shape transformations of lipid vesicles by insertion of bulky-head lipids

Lipid vesicles, in particular Giant Unilamellar Vesicles (GUVs), have been increasingly important as compartments of artificial cells to reconstruct living cell-like systems in a bottom-up fashion. Here, we report shape transformations of lipid vesicles induced by polyethylene glycol-lipid conjugate (PEG lipids). Statistical analysis of deformed vesicle shapes revealed that shapes vesicles tend to deform into depended on the concentration of the PEG lipids. When compared with theoretically simulated vesicle shapes, those shapes were found to be more energetically favorable, with lower membrane bending energies than other shapes. This result suggests that the vesicle shape transformations can be controlled by externally added membrane molecules, which can serve as a potential method to control the replications of artificial cells

De novo vesicle formation and growth: an integrative approach to artificial cells.

The assembly of artificial cells provides a novel strategy to reconstruct life's functions and shed light on how life emerged on Earth and possibly elsewhere. A major challenge to the development of artificial cells is the establishment of simple methodologies to mimic native membrane generation. An ambitious strategy is the bottom-up approach, which aims to systematically control the assembly of highly ordered membrane architectures with defined functionality. This perspective will cover recent advances and the current state-of-the-art of minimal lipid architectures that can faithfully reconstruct the structure and function of living cells. Specifically, we will overview work related to the de novo formation and growth of biomimetic membranes. These studies give us a deeper understanding of the nature of living systems and bring new insights into the origin of cellular life

Artificial in its own right

Artificial Cells, , Artificial Ecologies, Artificial Intelligence, Bio-Inspired Hardware Systems, Computational Autopoiesis, Computational Biology, Computational Embryology, Computational Evolution, Morphogenesis, Cyborgization, Digital Evolution, Evolvable Hardware, Cyborgs, Mathematical Biology, Nanotechnology, Posthuman, Transhuman

Artificial cells based on biodegradable polymersomes

The aim of the research that is described in this thesis is to develop biodegradable, biocompatible polymersomes that can serve as a basis for artificial cells. These artificial cells should be able to be delivered to the circulation, interact with specific sites where they perform their function, and biodegrade afterwards

Complex Coacervate Materials as Artificial Cells

Cells have evolved to be self-sustaining compartmentalized systems that consist of many thousands of biomolecules and metabolites interacting in complex cycles and reaction networks. Numerous subtle intricacies of these self-assembled structures are still largely unknown. The importance of liquid-liquid phase separation (both membraneless and membrane bound) is, however, recognized as playing an important role in achieving biological function that is controlled in time and space. Reconstituting biochemical reactions in vitro has been a success of the last decades, for example, establishment of the minimal set of enzymes and nutrients able to replicate cellular activities like the in vitro transcription translation of genes to proteins. Further than this though, artificial cell research has the aim of combining synthetic materials and nonliving macromolecules into ordered assemblies with the ability to carry out more complex and ambitious cell-like functions. These activities can provide insights into fundamental cell processes in simplified and idealized systems but could also have an applied impact in synthetic biology and biotechnology in the future. To date, strategies for the bottom-up fabrication of micrometer scale life-like artificial cells have included stabilized water-in-oil droplets, giant unilamellar vesicles (GUV’s), hydrogels, and complex coacervates. Water-in-oil droplets are a valuable and easy to produce model system for studying cell-like processes; however, the lack of a crowded interior can limit these artificial cells in mimicking life more closely. Similarly membrane stabilized vesicles, such as GUV’s, have the additional membrane feature of cells but still lack a macromolecularly crowded cytoplasm. Hydrogel-based artificial cells have a macromolecularly dense interior (although cross-linked) that better mimics cells, in addition to mechanical properties more similar to the viscoelasticity seen in cells but could be seen as being not dynamic in nature and limiting to the diffusion of biomolecules. On the other hand, liquid-liquid phase separated complex coacervates are an ideal platform for artificial cells as they can most accurately mimic the crowded, viscous, highly charged nature of the eukaryotic cytoplasm. Other important key features that researchers in the field target include stabilizing semipermeable membranes, compartmentalization, information transfer/communication, motility, and metabolism/growth. In this Account, we will briefly cover aspects of coacervation theory and then outline key cases of synthetic coacervate materials used as artificial cells (ranging from polypeptides, modified polysaccharides, polyacrylates, and polymethacrylates, and allyl polymers), finishing with envisioned opportunities and potential applications for coacervate artificial cells moving forward.</p

Communication and quorum sensing in non-living mimics of eukaryotic cells.

Cells in tissues or biofilms communicate with one another through chemical and mechanical signals to coordinate collective behaviors. Non-living cell mimics provide simplified models of natural systems; however, it has remained challenging to implement communication capabilities comparable to living cells. Here we present a porous artificial cell-mimic containing a nucleus-like DNA-hydrogel compartment that is able to express and display proteins, and communicate with neighboring cell-mimics through diffusive protein signals. We show that communication between cell-mimics allows distribution of tasks, quorum sensing, and cellular differentiation according to local environment. Cell-mimics can be manufactured in large quantities, easily stored, chemically modified, and spatially organized into diffusively connected tissue-like arrangements, offering a means for studying communication in large ensembles of artificial cells