title: Inkjet formation of unilamellar lipid vesicles for cell-like encapsulation.
abstract: Encapsulation of macromolecules within lipid vesicles has the potential to drive biological discovery and enable development of novel, cell-like therapeutics and sensors. However, rapid and reliable production of large numbers of unilamellar vesicles loaded with unrestricted and precisely-controlled contents requires new technologies that overcome size, uniformity, and throughput limitations of existing approaches. Here we present a high-throughput microfluidic method for vesicle formation and encapsulation using an inkjet printer at rates up to 200 Hz. We show how multiple high-frequency pulses of the inkjet's piezoelectric actuator create a microfluidic jet that deforms a bilayer lipid membrane, controlling formation of individual vesicles. Variations in pulse number, pulse voltage, and solution viscosity are used to control the vesicle size. As a first step toward cell-like reconstitution using this method, we encapsulate the cytoskeletal protein actin and use co-encapsulated microspheres to track its polymerization into a densely entangled cytoskeletal network upon vesicle formation.
authors: Department of Bioengineering, University of California, Berkeley, CA, USA.
authors: Jeanne C
authors: JC
authors: Stachowiak
authors: David L
authors: DL
authors: Richmond
authors: Thomas H
authors: TH
authors: Li
authors: Françoise
authors: F
authors: Brochard-Wyart
authors: Daniel A
authors: DA
authors: Fletcher
mesh_terms: D000199:Actins / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D008863:Microspheres; D011327:Printing / Q000295:instrumentation*; D013997:Time Factors; D053835:Unilamellar Liposomes / Q000138:chemical synthesis* / Q000737:chemistry*; D014783:Viscosity
chemical_list: D000199:Actins; D001704:Biopolymers; D008051:Lipid Bilayers; D008055:Lipids; D053835:Unilamellar Liposomes