Living organisms have acquired new functionalities by uptake and integration of species to create symbiotic life-forms. This process of endosymbiosis has intrigued scientists over the years, albeit mostly from an evolution biology perspective. With the advance of chemical and synthetic biology, our ability to create molecular-life-like systems has increased tremendously, which enables us to build cell and organelle-like structures. However, these advances have not been taken to a level to study comprehensively if endosymbiosis can be applied to non-living systems or to integrate living with non-living matter. The aim of the research described in the ARTISYM proposal is to establish the field of artificial endosymbiosis. Two lines of research will be followed. First, we will incorporate artificial organelles in living cells to design hybrid cells with acquired functionality. This investigation is scientifically of great interest, as it will show us how to introduce novel compartmentalized pathways into living organisms. It also serves an important societal goal, as with these compartments dysfunctional cellular processes can be corrected. We will follow both a transient and a permanent approach. With the transient route biodegradable nanoreactors are introduced to supply living cells temporarily with novel function. Functionality is permanently introduced using genetic engineering to express protein-based nanoreactors in living cells, or via organelle transplantation of healthy mitochondria in diseased living cells. Secondly I aim to create artificial cells with the ability to perform endosymbiosis; the uptake and presence of artificial organelles in synthetic vesicles allows them to dynamically respond to their environment. Responses that are envisaged are shape changes, motility, and growth and division. Furthermore, the incorporation of natural organelles in liposomes provides biocatalytic cascades with the necessary cofactors to function in an artificial cell

This proposal is on modelling of 3 phase gas-solid-liquid multi-component flows with catalyst particles, which are frequently encountered in industrial applications, but have not been tackled fundamentally before due to their complexity. Dense multi-phase flows have been intensively researched because of their scientifically interesting transport phenomena and industrial applications. Considerable progress has been made for gas-solid and gas-liquid two-phase flows. However, catalytic multicomponent three-phase flows have received relatively little attention despite their importance for the production of clean synthetic fuels, base chemicals, and many other products. Multiphase transport phenomena in such systems are poorly understood due to their complexity. Therefore the design of processes is cumbersome. In addition, the process operation is often far from optimal in terms of energy and feedstock utilization. Therefore significant improvements are required to boost the efficiency of three-phase systems, which demands for a better understanding of the transport fundamentals and complex interplay with chemical reactions and availability of predictive tools. The main underlying problem is the wide range of length scales: suspended catalyst particles have a size of 100-200 μm, whereas the diameter of industrial reactors is 5-10 meters. To tackle this problem a multi-scale modeling strategy is required. At the finest scale detailed models take into account the interaction between the phases. These interactions are condensed in closure laws for mass, momentum and heat exchange that feed so-called Euler-Lagrange models, which can then be used to compute the flow structures on a much larger (industrial) scale. The key innovative aspect of this proposal is the integrated approach including incorporation of multi-component chemical transformations and the validation on basis of one-to-one comparison of the of the computational results with experiments.

Many supramolecular systems have been inspired by nature, but the number of supramolecular systems that are truly functional in water at the low concentrations required for biomolecular studies are very limited. Cucurbiturils are one of a few select supramolecular systems that show great promise for the modulation of protein assemblies in biologically relevant media, but they require better means to control homo- and heterodimerization. In order to effect strong and selective heterodimerization I will design and synthesize a wide range of complementary guest pairs, using chemical and electronic concepts such as π-π stacking and electronic donor−acceptor pairs. After testing these on the cucurbituril host-guest system, they will be assessed on heterodimeric protein assemblies such as split luciferase. As many biological processes require multimeric protein assemblies, I will develop novel supramolecular constructs to gain control over the formation of such assemblies. By constructing protein-coupled cucurbiturils and developing novel double cucurbituril systems, trimeric and tetrameric protein assemblies will be assessable. Development of these advanced supramolecular tools is crucial in order to access synthetic signaling platforms with potential for molecular diagnostics.

The living cell is an active system that can display autonomy by implementation of dissipative out-of-equilibrium and self-regulated oscillatory behaviours. Manifestation of these dynamic traits into artificial microcompartments (termed artificial cell or protocell) will advance the construction of “smart” artificial cells and the development of synthetic protobiology. Even though numerous reports have illustrated the feasibility of fuel-depleted out-of-equilibrium reactions/behaviors in artificial cells, implementation of more advanced self-regulated artificial cells capable of sustained cell-like dynamics and homeostasis is still very challenging due to the lacks of apparatus and strategy. The overall aim of this proposal is therefore to construct an autonomous artificial cell capable of self-regulated oscillation, which can be coupled to sustained out-of-equilibrium behaviors and environmental homeostasis by chemo-chemical/chemo-mechanical transition modes. Implementation of this proposed work will advance development of synthetic protobiology by producing “smart” protocells with cell-like autonomy. Coupling the self-regulated oscillations to other forms of out-of-equilibrium behaviors by chemo-chemical/chemo-mechanical transitions will further extend the significance of this work by offering a strategy to construct smart and adaptive materials (e.g., autonomous soft robotics) for engineering applications.

Recently, visible light photoredox catalysis has come to the focal point of the organic synthetic field and holds promise to use solar irradiation to establish important chemical bonds in the synthesis of complex organic molecules. However, most reports thus far use transition metal complexes based on rare and expensive iridium and ruthenium. In this Marie Curie proposal, metal oxide semiconductors (MOS) will be applied as abundant and cheap visible light photocatalysts to establish C-C and C-N linkages in organic molecules in batch and photomicroflow reactors. To extend their absorption to the visible light range, I will study the formation of so-called ligand-to-metal charge transfer (LMCT) complexes with different adsorbates/ligands covalently linked to the surface of the MOS. The effect of linkers, ligands, different organic solvents, concentrations, as well as reaction times will be studied in the formation of these complexes. The LMCT complexes will be fully characterized with spectroscopic techniques. Next, these new photocatalysts will be evaluated in valuable C-C and C-N forming organic reactions. Furthermore, mechanistic studies will be carried out to aid the discovery process and to further optimize the photocatalysts. Finally, the reactions will be carried out in continuous-flow reactors to increase the efficiency of the photocatalytic transformation. Hereto, a slurry Taylor flow regime will be used and a recycling strategy will be developed to efficiently reuse the photocatalyst. We will also use so-called Luminescent Solar Concentrator PhotoMicroreactors (LSC-PM) to enable the use of solar energy. During this fellowship, I aim to strengthen both my scientific and soft skills required to start an independent researcher career. In addition, I intend to expand my scientific network by starting collaborations with leading experts in both academia and industry.