Researchers Use Artificial Cells to Make Nanoparticles

(a) Vesicles with different reactants have different fluorescent substances in their membranes. (b) Red fluorescent nanoparticles form when the bubbles fuse. (c) The particles can be seen as bright dots under a transmission electron microscope. Image courtesy of the Max Planck Institute of Colloids and Interfaces

From the wire: In a study conducted at the Max Planck Institute of Colloids and Interfaces, researchers created nanoparticles that can act as tiny light sources within cells. Potential applications of the nanoparticles, which were created using artificial membranes resembling cells, include display screens and optical computing.

“We used the fact that cells represent a closed reaction container as a model for the synthesis of nanoparticles,” the leader of the Max Planck Institute of Colloids and Interfaces membrane study group, Rumiana Dimova, explains. Membranes are the boundaries of the cells, being strong enough to contain the nucleus, cytoplasm, genes, proteins, and countless processes inside its perimeter, while at the same time remaining permissive enough to allow for the necessary substances to pass in and out of the cell, regulating its functions.

The membrane bubbles (vesicles) that the team built are similar to cellular membranes, in that they also provide a closed reaction container. They created two types of vesicles, one loaded with sodium sulphide, and the other with cadmium chloride. With the aid of a short, powerful, electric burst, the team fused the two membranes together, allowing the reactants to merge. As a result, the non-water soluble cadmium sulphide was formed, which precipitated in the form of nanoparticles.

“Because the reactants are only present to a limited extent in the fused bubbles, the particles only grow to a size of four nanometres,” Rumiana Dimova adds. She says that her group was able to observe these reactions by marking each of the reacting substances with fluorescent molecules. Through a powerful microscope, the precipitation of nanoparticles became visible, as fluorescent light illuminated the eerie scene. “With our method, we succeeded for the first time in producing particles with a certain diameter in vesicles whose size corresponds to that of cells,” the expert concludes. Previously, biologists thought that cells depended on the help of peptides for the synthesis of nanoparticles. However, as Dimova and her colleagues have discovered, it can also be done without them.

More information on the research is available from the Max Plank Society.

Tags: display screens, Max Planck Institute of Colloids and Interfaces, nanoparticles, optical computing