Poster N17 - Large scale assembly of giant vesicles for use as prototissues and cell mimics

Introduction: Cells in blood, such as red blood cells and platelet range in size broadly from 1 micrometer to 10 micrometers in diameter, while other cell types are between 15 and 50 micrometers in diameter. Synthetic liposomes in this size range are broadly classified as giant unilamellar vesicles (GUVs). While fabrication of large quantities of small unilamellar vesicles, liposomes with diameters between 100 – 200 nm is straightforward, fabricating large quantities of GUVs is still a challenging task. In this talk, we demonstrate the latest understanding of the mechanism of assembly of GUVs that enable lab-scale fabrication of GUVs using the PAPYRUS method. We obtain numbers and yields sufficient to perform in vitro and in vivo experiments for studying the potential of GUVs for use in biomedical applications such as blood substitutes, drug delivery vehicles, and synthetic tissues.

Materials and

Methods: The general procedure of assembly uses the PAPYRUS (Paper-Abetted amPhiphile hYdRation in aqUeous Solutions) method. Phospholipid mixtures of suitable composition and concentration in chloroform are drop-casted onto sheets of nanocellulose paper. After solvent evaporation, the dry lipid-coated paper is hydrated in aqueous buffers. After 1 hour, the GUVs are harvested from the surface and then processed via differential centrifugation to obtain populations with the desired distribution of sizes.

Results, Conclusions, and Discussions: GUVs with size ranges of 1 to 10 micrometers and 10 to 50 micrometers with total numbers on the order of billions can be obtained within 2 hours in a single preparation. Parallelization of the preparation increases the yields while limiting the time that is required. GUVs can be dispersed in physiological saline and other biocompatible buffers.

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