Christian Nehls

 

Start-up project

Copyright: © C. Nehls

Microfluidic encapsulation of pathogens to study their exit: A bottom-up model system for intracellular compartments

Dr. Christian Nehls (Research Center Borstel – Leibniz Lung Center)

The limited habitat volume of intracellular pathogens enclosed in cellular compartments is a decisive factor in understanding their survival and exit strategies. Experiments with compartment-entrapped pathogens are limited in terms of the only indirect influence on the content of the compartment, handling and natural variability of the system.

In microfluidic systems, uniform cell-sized liposomes can be generated for analysis with minimal sample volume and high throughput. They are surrounded by a lipid bilayer and form from double emulsion droplets by self-detachment of an octanol pocket. The option of trapping thousands of liposomes in microfluidic systems provides a unique basis for performing optical measurements on single liposomes with high statistics and for comparing multiple experimental conditions in parallel.

We plan the establishment of lipid-enclosed, microfluidic-derived model systems for the restricted volume of intracellular compartments in which single or multiple pathogens will be selectively encapsulated. Two approaches are taken for this purpose: First, water-in-oil droplets which, when lipids are added to the oil phase, are surrounded by a lipid monolayer. The droplets are very robust and can be easily manipulated in microfluidic systems. Second, lipid liposomes, that are subject to limitations in terms of lipid composition and suitable aqueous phases. Both systems allow excellent standardization of experiments and the targeted and precisely co-enclosure of effector molecules. The droplets and vesicles will be systematically immobilized, manipulated and microscopically examined in microfluidic arrays. As a first biological system, the pathogens Candida albicans and Candida glabrata will be encapsulated and first proof-of-principle experiments will be performed.