Sequential bottom-up assembly of mechanically stabilized synthetic cells by microfluidics

Compartments for the spatially and temporally controlled assembly of biological processes are essential towards cellular life. Synthetic mimics of cellular compartments based on lipid-based protocells lack the mechanical and chemical stability to allow their manipulation into a complex and fully functional synthetic cell. Here, we present a high-throughput microfluidic method to generate stable, defined sized liposomes termed /`droplet-stabilized giant unilamellar vesicles (dsGUVs)[rsquor]. The enhanced stability of dsGUVs enables the sequential loading of these compartments with biomolecules, namely purified transmembrane and cytoskeleton proteins by microfluidic pico-injection technology. This constitutes an experimental demonstration of a successful bottom-up assembly of a compartment with contents that would not self-assemble to full functionality when simply mixed together. Following assembly, the stabilizing oil phase and droplet shells are removed to release functional self-supporting protocells to an aqueous phase, enabling them to interact with physiologically relevant matrices

Battling Bacteria with Free and Surface-Immobilized Polymeric Nanostructures

With the discovery of antibiotics, bacterial infections and previously fatal diseases suddenly became curable. During the golden era of antibiotics, new classes of antibiotics were discovered. However, antibiotic-resistant bacteria rapidly evolved while fewer new antimicrobial drugs were discovered and marketed. Today, a growing number of infections are becoming harder to treat as the bacterial resistance is spreading and antibiotics become less effective. Evidently, there is an urgent demand for new strategies that efficiently battle pathogenic bacteria. Among emerging technologies, those involving polymeric nanostructures, especially polymersomes, offer many features that make them attractive candidates for battling infections. Polymersomes can be designed to be biocompatible and respond to various environmental signals. They are more robust than liposomes and can host hydrophobic and hydrophilic antimicrobial compounds, which can be released and act locally. Last but not least, they are biodegradable. Moreover, platforms comprising polymeric nanostructures can be designed as sensors for diagnosing infections. Many of these approaches require the immobilization of the antimicrobial nanostructures on a surface whereby the activity is localized to a specific region. Several recent examples of polymeric nanostructures with antimicrobial activity, both free in solution or immobilized on surfaces, are highlighted and discussed in this chapter