Product Spotlight: Lipids for GUVs

Posted on June 16, 2021

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Current events reinforce the importance of lipid-based delivery systems, and Avanti products are perfect for lipid-based particle formulations. Keep reading to learn about a special class of particles, Giant Unilamellar Vesicles (GUVs), and their interesting applications!

Since the beginning of the COVID-19 pandemic lipid nanoparticles have been newsorthy science. But other types of lipid-based formulations have also been extensively studied. In the last year, Avanti’s products have also been used to make unilamellar vesicles. Let's take a look at some exciting research displaying how Avanti’s products are being used for this application.

In the first article published in 2020, the preparation and use of hybrid unilamellar vesicles formulated with phospholipids and block copolymers is described. Both of these chemical components have the ability to self-assemble into a variety of nanostructures. Combining these two components to create a hybridosome could have incredible implications. Phospholipids chemistry is fairly limited in comparison to block copolymer chemistry. Block copolymers can be functionalized with a variety of other chemical groups. Combining the properties of phospholipids and block copolymers could be useful for controlled drug delivery, artificial cell development, and biosensors. This article focuses on the development of phospholipid and block copolymer unilamellar vesicles and their ability to crystallize at room temperature. The vesicles were prepared using the phospholipid, DPPC, and the block copolymer, mPEG-b-PCL.

The giant hybrid unilamellar vesicles were then studied using confocal laser scanning microscopy (CLSM) to observe the phospholipid-rich and block copolymer-rich phase-separated domains. These domains were easily visible using fluorescent labeling techniques. In this case, lissamine rhodamine DPPE was used to label phospholipids and fluorescein isothiocyanate was used to label block copolymers. The resulting hybrid vesicles are smooth resembling the pure DPPC GUVs. X-ray scattering also revealed that these components did indeed form a hybrid vesicle and that DPPC remained in the gel-state while PCL displayed diffraction peaks consistent with the existence of crystalline domains.

To read more about this hybridosome characterization and how this could lead to new materials for applications in bioinspired separation membranes and drug delivery, click HERE!

The second featured article dealing with GUV preparation was published earlier this year. Historically, small unilamellar vesicles (SUVs) have been used for biomedical applications, but these vesicles pose notable limitations that can be solved by using GUVs. The lack of reliable high-throughput technology for GUV-systems has lead to a lack of knowledge of their interactions with cells. The research in this study aimed to present a microfluidic-based mechanical droplet-splitting pipeline for the production of carrier-GUVs with diameters of ~2µm. This method allows for highly efficient cargo loading and unprecedented control over the biological and physicochemical properties of GUV membranes.

Several of Avanti’s products were utilized in this study including Natural and Synthetic Phospholipids, Polymer Lipids, Functionalized Phospholipids, Fluorescent Phospholipids, Chelator Lipids, and the Mini-Extruder. Using Avanti lipids, the research team was able to develop a method for highly efficient droplet GUV preparation with three subsequent steps: 1) well controlled assembly of dsGUVs, 2) dsGUV mechanical splitting, and 3) release of dsGUV into a physiological environment. This method allows a researcher to control the size, cargo, robustness during handling, specificity, and strength of interactions. Bacolovirus (BV) was used as “proof of concept” and proved that BV-loaded GUVs can be applied for the transport and delivery of very large, complex cargo to desired cells and tissues. They postulate that GUVs could carry cargo such as ensembles of viruses, drug releasing porous microparticles, unprecedented quantities of imaging probes, and other nanodevices. The applications of this technology is extremely promising in the future. To read more about this technology and it potential applications, click HERE!

If you are interested your own GUV research, we offer useful “how to” protocols for Giant Vesicle Preparation. Check it out on our website!