Cubosomes are small biological 'capsules' that can deliver molecules of nutrients or drugs with high efficiency. They have a highly symmetrical interior made of tiny cubes of assembled fat molecules similar to the ones in cell membranes. This also means that cubosomes are safe to use in living organisms. Such features have triggered great interest in the pharmaceutical and food industry, who seek to exploit the structure of cubosomes for the controlled release of molecules, improving the delivery of nutrients and drugs.
EPFL scientists, working with Nestlé, have now been able to study the 3D structure of cubosomes in detail for the first time. Published in Nature Communications, the breakthrough can help and promote the use of cubosomes in medicine and food science.
Molecules of a drug or a nutrient contained inside a cubosome can move by using the numerous tiny channels that make up its structure's interior.
The pharmaceutical industry already uses a similar system for drug delivery: the liposomes, which are also made of fats but in the shape of a sphere. Their intricate internal channels give cubosomes a very high internal surface, which offers great potential for the controlled delivery of nutrients and drugs.
In short, the properties of cubosomes, like other lipid-based delivery vessels, depend on their particular structures. The problem is that cubosomes are self-assembled, occurring 'spontaneously' after putting together the right ingredients (generally fats and a detergent) under the right conditions.
This means that scientists have limited control over their final structure, which makes it hard to optimize their design. In addition, it is very difficult to 'see' the interior of a cubosome and map out the various arrangements of its channels.
Davide Demurtas and Cécile Hébert from EPFL's Interdisciplinary Centre for Electron Microscopy (CIME), working with Laurent Sagalowicz at the Nestlé Research Center in Lausanne, have now uncovered the interior 3D structure of cubosomes, and have successfully matched their real-life findings to computer simulations.
The researchers used a microscopy technique called 'cryo-electron tomography' (CET). Their method involves embedding cubosomes in a type of 'glass' ice that does not form crystals, which would damage the cubosomes. The samples are kept at -170oC. The microscope then takes photographs while tilting the cubosome at different angles. The technique, which was carried out at CIME, can reconstruct the three-dimensional information to create images of the cubosomes in their native state and with unprecedented detail.
"This method allows us to get information about everything, both the inside and outside of the cubosomes," says Cécile Hébert. "Because the CET microscope distinguishes the different densities between cubosome and ice, it is very sensitive and precise."
The CET images clearly showed the internal cubic structure, as well as the internal 3D organization of the channels. The researchers also compared the images to the prevailing mathematical models used to make computer simulations of the interface between the interior and exterior. The real-life data successfully matched the theory.
"With this approach we can now forge a new understanding of the structure of the cubosomes' interior," says Davide Demurtas. The success is expected to make the study and design of cubosomes with controlled macroscopic properties (e.g. controlled release) easier.
This work represents a collaboration of EPFL's Interdisciplinary Centre for Electron Microscopy (CIME) with the Nestlé Research Center Lausanne, EPFL's Institute of Cancer Research, and the Department of Health Science & Technology of ETH Zurich.
Demurtas D, Guichard P, Martiel I, Mezzenga R, Hébert C, Sagalowicz L. Direct visualization of dispersed lipid bicontinuous cubic phases by cryo-electron tomography. Nature Communications 17 Nov. 2015. DOI: 10.1038/NCOMMS9915.
Nik Papageorgiou | EurekAlert!
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering