Studies on intracellular delivery of carboxyl-coated CdTe quantum dots mediated by fusogenic liposomes

Abstract

The use of Quantum Dots (QDs) as fluorescent probes for understanding biological functions has emerged as an advantageous alternative over application of conventional fluorescent dyes. Intracellular delivery of QDs is currently a specific field of research. When QDs are tracking a specific target in live cells, they are mostly applied for extracellular membrane labeling. In order to study intracellular molecules and structures it is necessary to deliver free QDs into the cell cytosol. In this work, we adapted the freeze and thaw method to encapsulate water dispersed carboxyl-coated CdTe QDs into liposomes of different compositions, including cationic liposomes with fusogenic properties. We showed that labeled liposomes were able to fuse with live human stem cells and red blood cells in an endocytic-independent way. We followed the interactions of liposomes containing QDs with the cells. The results were minutely discussed and showed that QDs were delivered, but they were not freely diffused in the cytosol of those cells. We believe that this approach has the potential to be applied as a general route for encapsulation and delivery of any membrane-impermeant material into living cells.

Giant Unilamellar Vesicles Formed by Hybrid Films of Agarose and Lipids Display Altered Mechanical Properties

“…Traditionally, GUVs have been used to study biophysical properties of membranes including elasticity (4,5) and domain formation (6,7), their interaction with membrane active molecules (8) and nanoparticles (9,10), membrane wetting (11), vesicles as chemical reactors (12,13) and artificial cells (14), and for many other applications (15,16). Currently, there is a large variety of methods for production of GUVs (3,15) such as the classical electroformation method (17) (with some recent modifications (18)), simple gentle hydration (19), phase-reverse evaporation (20), emulsion and microfluidic methods (14,21).…”

Fluorescent liposomes to probe how DOTAP lipid concentrations can change red blood cells homeostasis

“…For other cells lines, this liposomal composition can be used as a started point and, modifications in DOTAP concentrations could be done when necessary. Moreover, these fusogenic liposomes have potential to be used for nanoparticles, such as fluorescent quantum dots, encapsulation as we reported before [16] . These fusogenic liposome can allow researchers to delivery nanoparticles into cell' citosol and enjoy the full potential of fluorescent probes, for a better comprehension of intracellular processes.…”

Cell Uptake of Lipid‐Coated Diamond

“…Most interestingly, liposomes might be able to fuse with the cell membrane and thus offer a way to circumvent the natural endocytosis or speed up uptake. The same process has already been demonstrated for other nanoparticles that were encapsulated with lipids . This is advantageous for all applications where the desired location is not the endosome.…”

“…The same process has already been demonstrated for other nanoparticles that were encapsulated with lipids. [26,27] This is advantageous for all applications where the desired location is not the endosome. Since endosomes usually fuse with lysosomes, the particle is subjected to a harsh environment.…”