High-Throughput Microfluidic Instrument for Constructing Custom Synthetic Vesicles with Asymmetric Membranes

Background: 

The ability to fabricate complex model membrane systems that are physiologically relevant to their natural systems has been a
challenge in past decades. Conventional methods such as electroformation, gel hydration, bulk inverted emulsion, extrusion, and microfluidics have addressed the needs in fabricating synthetic lipid bilayer membrane vesicles (e.g., giant unilamellar vesicles, > 1 μm); however, the lipid profile architecture and composition, encapsulation efficiency, fabrication rate and yield have not been satisfactory. 

Technology Overview: 

We have built a high-throughput microfluidic device for constructing custom synthetic vesicles with asymmetric membranes. Synthetic vesicles are symmetric; therefore, this instrument has the potential to transform membrane biology research by better imitating naturally-occurring membranes that are asymmetric (i.e. each leaflet of the bilayer contains a different lipid composition). The instrument provides simultaneous control over every aspect of vesicle quality: membrane lipid asymmetry, luminal content, unilamellarity, size over several orders of magnitude, uniformity, and throughput. Membranes with numerous architectures can be created, including asymmetric phospholipid-phospholipid and phospholipid-lipopolysaccharide (LPS) bilayers. The instrument provides membrane asymmetries as high as 95% immediately after vesicle formation. Over 80% of the vesicles remain stable for at least 6 weeks and the asymmetry is maintained for over 30 hours. The vesicles can be reliably transferred from the instrument and used for fundamental biofilm research, vaccine development, or other novel applications.  

Advantages: 

• Vesicle asymmetry
• Capability to synthesize vesicles with lipopolysaccharide (LPS) bilayers
• Better representation of naturally occurring vesicles