Cell mimicry: bottom-up engineering of life

Biology is well equipped in exploiting a large number of out of equilibrium processes to support life. A complete understanding of these mechanisms is still in its infancy due to the complexity and number of the individual components involved in the reactions. However, a bottom up approach allows us to replicate key biological processes using a small number of basic building blocks. Moreover, this methodology has the added advantage that properties and characteristics of the artificial cell can be readily tuned and adapted. 

Here, I will present strategies for the design and synthesis of artificial cells based on hydrophobic effects such as lipid vesicles and proteinosomes and liquid-liquid phase separation of oppositely charged components (coacervates) and describe how these compartments may be used as platforms for implementing dynamic biological behaviour. 

Dr TY Dora Tang, Max Planck Institute for Molecular Cell Biology and Genetics, Germany

Dr TY Dora Tang, Max Planck Institute for Molecular Cell Biology and Genetics, Germany

T-Y Dora Tang received her PhD from Imperial College London, UK, in 2010 in the area of membrane biophysics. After 1 year as an EPSRC knowledge transfer secondee at Diamond Light Source, Oxfordshire, UK she undertook a post-doc at the University of Bristol, UK, in the areas of origin of life and then synthetic biology. In 2016 she started her independent lab at the MPI-CBG, Dresden as part of the MaxSynBio consortium. Her research lies between biophysics, synthetic biology and materials chemistry with the goal of building minimal synthetic cellular systems as physical models to understand the role of compartmentalisation in the origin of life and in modern biology.

Bottom-up synthetic biology aims to substitute for missing/lost cellular activity or to add non-native function to mammalian cells and tissue. We focus on hydrogel-based artificial cells equipped with a specific life-like function, in particular, energy generation and cellular communication. 

The creation of self-sustaining systems require energy generation. In mammalian cells, mitochondria are responsible for the chemically driven adenosine triphosphate (ATP) synthesis. Here, mitochondria are used as a natural ATP producing subunit in hydrogel-based artificial cells. We co-encapsulated the ATP-dependent enzyme firefly luciferase with purified mitochondria to demonstrate the utilization of mitochondrially produced ATP in a cell-sized carrier, exemplified by the bioluminescent decarboxylation of D-luciferin. 

Collective behaviour in multicellular assemblies and on tissue level requires communication. Consequently, the integration of artificial cells with mammalian cells would benefit from supportive signal exchange between the artificial and natural entity. First, a one-way signal transfer is established by equipping two different types of artificial cells with catalytic function using metalloporphyrins as artificial enzymes that mimic cytochrome P450 enzyme (CYP450) activity. Second, artificial cells that can eavesdrop on mammalian cells in 2D and 3D are demonstrated. 

Professor Brigitte Städler, Aarhus University, Denmark

Professor Brigitte Städler, Aarhus University, Denmark

Brigitte Städler (ORCID: 0000-0002-7335-3945) is Associate Professor at the Interdisciplinary Nanoscience Center at Aarhus University, Denmark since 2015. Prior to this, she obtained her PhD from ETH Zurich, Switzerland followed by post doc time at the University of Melbourne, Australia and an Assistant Professor position at Aarhus University. Currently, she is the head of the ‘Laboratory for Cell Mimicry’, an interdisciplinary group working in the area of artificial biology focusing on nature inspired solutions to address medical challenges. Highlights include the first report on i) intracellularly active subcompartmentalised nanoreactors, ii) the integration of artificial cells with liver cells, and iii) directional self-propelled nanobots. She has published over 100 peer-reviewed publications, and obtained multiple fellowships including the L’Oreal/UNESCO - For Women in Science Fellowship, Denmark, the Carlsberg Foundation – Distinguished Associate Professor Fellowship and an ERC Consolidator Grant.

Membranes play a vital role in a variety of physiological processes. Recapitulating these processes outside of the cell may allow us to better understand them as well as design an entirely new class of materials that can sense, transport, or target important biological signals and molecules. In this talk, I will present our recent work using model membranes (ex. liposomes and polymersomes) and cell-free expression systems to (1) uncover the role of membrane mechanical properties on the folding of model membrane proteins and (2) design a membrane-based nanoparticle for biosensing applications. First, I will describe how membrane physical properties, such as elasticity and hydrophobic thickness, impacts the folding, location, and integration of model membrane proteins. Next, I will describe our recent work to demonstrate how compartmentalization of cell-free extracts in membranes provides new capabilities for cell-free biosensing. Our approach, bridging synthetic biology techniques and model membrane assembly, provides an innovative yet simple method to probe the role of membrane composition and biophysical properties on protein dynamics and to advance the design of drug delivery carriers. 

Professor Neha Kamat, Northwestern University, US

Professor Neha Kamat, Northwestern University, US

The Kamat Lab's interests lie in constructing minimal systems, or artificial cells, as a tool to understand and recreate certain cellular behaviours. They use emerging engineering methods in material science and synthetic biology to construct in vitro models of cellular membranes that can couple membrane biophysical processes to chemical and genetic processes, yielding new cellular mimetic biomaterials, capable of complex sensing, signalling, and responsive behaviours. Their particular interests lie in understanding the role of the bilayer membrane in membrane protein folding and function and designing biosensors for environmental analytes. Neha received a BS in Bioengineering from Rice University and a PhD in Bioengineering from the University of Pennsylvania. She currently holds a Young Investigator Award from the Air Force Research Office, the ACS Synthetic Biology Young Innovator Award, and an NSF CAREER Award.

A major goal of synthetic biology is to understand the transition between non-living matter and life. The bottom-up development of an artificial cell would provide a minimal system with which to study the border between chemistry and biology. So far, a fully synthetic cell has remained elusive but chemists are progressing towards this goal by reconstructing cellular subsystems. Cell boundaries, likely in the form of lipid membranes, were necessary for the emergence of life. In addition to providing a protective barrier between cellular cargo and the external environment, lipid compartments maintain homeostasis with other subsystems to regulate cellular processes. Our lab is exploring different chemical approaches for making cell-mimetic compartments. Synthetic strategies to drive membrane formation and function, including bioorthogonal ligations, dissipative self-assembly, and reconstitution of biochemical pathways, will be discussed. Chemical strategies aim to recreate the interactions between lipid membranes, the external environment, and internal biomolecules, and will clarify our understanding of life at the interface of chemistry and biology.

Professor Neal Devaraj, University of California San Diego, US

Professor Neal Devaraj, University of California San Diego, US

Neal K Devaraj is a Professor and Murray Goodman Endowed Chair in the Department of Chemistry and Biochemistry at the University of California, San Diego. A major research thrust of his lab is understanding how non-living matter, such as simple organic molecules, can assemble to form life. Along these lines, he has developed approaches for the in situ synthesis of synthetic cell membranes by using selective reactions to ‘‘stitch’’ together lipid fragments. His lab has also made contributions towards applying bioconjugation reactions to understand the role of specific lipid species in living cells. His work has been recognized by the 2017 ACS Award in Pure Chemistry, being selected as the 2018 Blavatnik National Laureate in Chemistry, and the 2021 Tetrahedron Young Investigator Award in Bioorganic and Medicinal Chemistry.

Medicine is taking its first steps towards patient-specific cancer care. Nanoparticles have many potential benefits for treating cancer, including the ability to transport complex molecular cargoes including siRNA and protein, as well as targeting to specific cell populations. 

The talk will discuss ‘barcoded nanoparticles’ that target sites of cancer where they perform a programmed therapeutic task. Specifically, liposomes that diagnose the tumour and metastasis for their sensitivity to different medications, providing patient-specific drug activity information that can be used to improve the medication choice. 

The talk will also describe how liposomes can be used for degrading the pancreatic stroma to allow subsequent drug penetration into pancreatic adenocarcinoma, and how nanoparticle’ biodistribution and anti-cancer efficacy is impacted by patient’ sex and more specifically, the menstrual cycle. 

The evolution of drug delivery systems into synthetic cells, programmed nanoparticles that have an autonomous capacity to synthesize diagnostic and therapeutic proteins inside the body, and their promise for treating cancer and immunotherapy, will be discussed.

Dr Avi Schroeder, Technion - Isreal Institute of Technology, Isreal

Dr Avi Schroeder, Technion - Isreal Institute of Technology, Isreal

Biography will available soon

Living cells take advantage of spontaneous aggregation of certain proteins and RNA species to spatially and dynamically organize a variety of molecules and reactions. Taking inspiration from nature, our group is developing methods to build assemblies, condensates and patterns using structured motifs built with artificial DNA, that are relevant to the synthesis of self-regulated, autonomous biomaterials. I will present our recent results on controlling the rate of self-assembly and condensation and dissolution of artificial DNA motifs using chemical reactions. I will also discuss mathematical models that support and guide our experiments by capturing specific and non-specific interactions among the motifs.

Professor Elisa Franco, University of California Los Angeles, US

Professor Elisa Franco, University of California Los Angeles, US

Elisa Franco is an Associate Professor in Mechanical & Aerospace Engineering and Bioengieering at UCLA.  
She holds a Ph.D. in Control and Dynamical Systems from the California Institute of Technology, and  a Ph.D. in Automation from the University of Trieste, Italy. She received the NSF CAREER award, the Rose Hills Foundation Young Investigator award, and is a Hellman Fellow. The research interests of the Franco group are in the areas of biological feedback and DNA/RNA nanotechnology, with focus on design, modeling, and synthesis of circuits and responsive materials using nucleic acids and proteins. Their work is funded by NSF, DOE, Sloan and the Broad Stem Cell Research Center at UCLA. Prof. Franco is an associate editor with IEEE Control Systems Letters, an elected member of the IEEE Control Systems Society Board of Governors and a council member of the Engineering Biology Research Center (EBRC).

 

The evolution of cellular compartments for spatially and temporally controlled assembly of biological processes was an essential step in developing life by evolution. Synthetic approaches to cellular-like compartments are still lacking well-controlled functionalities, as would be needed for more complex synthetic cells. With the ultimate aim to construct life-like materials such as a living cell, matter-to-life strives to reconstitute cellular phenomena in vitro – disentangled from the complex environment of a cell. In recent years, working towards this ambitious goal gave new insights into the mechanisms governing life. With the fast-growing library of functional modules assembled for synthetic cells, their classification and integration become increasingly important. We will discuss strategies to reverse-engineer and recombine functional parts for synthetic eukaryotes, mimicking the characteristics of nature’s own prototype. Particularly, we will focus on large outer compartments, complex endomembrane systems with organelles and versatile cytoskeletons as hallmarks of eukaryotic life. Moreover, we identify microfluidics and DNA nanotechnology as two highly promising technologies which can achieve the integration of these functional modules into sophisticated multifunctional synthetic cells. 

Professor Joachim Spatz, Heidelberg University, Germany

Professor Joachim Spatz, Heidelberg University, Germany

Joachim P Spatz joined the Max Planck Institute for Medical Research in 2016 as Director. From 2004–2015 he was Director at the Max Planck Institute for Intelligent Systems (former MPI for Metals Research). Since then he has also been a Full Professor at the University of Heidelberg and head of the Department of Biophysical Chemistry. He was an Associate Professor for Biophysical Chemistry at the University of Heidelberg from 2000–2004. From 1999–2000 he received his habilitation in Physics at the University of Ulm. He was a PostDoc in the group of Professor Jacques Prost and Albrecht Ott at the Institut Curie, Paris, in 1997–1998. He received his Diploma in Physics (1994) and his PhD in Physics (1996) from the University of Ulm under the supervision of Professor Möller (founding Director of the Leibniz Institute of Interactive Materials in Aachen). He is a member of the Heidelberg Academy of Sciences and Humanities. Among other awards, he received the Gottfried Wilhelm Leibniz Prize of the German Science Foundation in 2017.

Synthetic biology (SB) is one of the most promising fields of research for the 21st century. SB offers powerful new ways to improve human health, build the global economy, manufacture sustainable materials, and address climate change. However, current access to SB-enabled breakthroughs is unequal, largely due to bottlenecks in infrastructure and education. Here, I describe our efforts to re-think the way we engineer biology using cell-free systems to address these bottlenecks. We show how the ability to readily store, distribute, and activate low-cost, freeze-dried cell-free systems by simply adding water has opened new opportunities for on-demand biomanufacturing of vaccines for global health, point-of-care diagnostics for environmental safety, and education for SB literacy and citizenship. By integrating cell-free systems with artificial intelligence (AI), we also show the ability to accelerate the production of carbon-negative platform chemicals. Looking forward, advances in engineering tools and new knowledge underpinning the fundamental science of living matter will ensure that SB helps solve humanity’s most pressing challenges.  

Professor Mike Jewett, Northwestern University, US

Professor Mike Jewett, Northwestern University, US

Biography will available soon