Cubosomes are discrete, sub-micron, nanostructured particles of the bicontinuous cubic

liquid crystal Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as i ...

line phase. The term "bicontinuous" refers to two distinct

hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are n ...

regions separated by the bilayer. Bicontinuous cubic crystalline materials have been an active research topic because their structure lends itself well to controlled-release applications. Cubosomes are liquid crystalline nano-structures formed from the cubic phase of lipids, such as monooleate, or any other amphiphilic macromolecules with the unique property to be dispersed into particles. Nano-vehicles are generated from a self-assembled lipid mixture and studied by means of high-resolution cryogenic

transmission electron microscope Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a gr ...

(cryo-TEM). These structures have been observed to naturally occur in

mitochondrial membrane A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

s and in stressed cells. Cubosomes are formed at controlled temperatures into lipid bi-layer twisted into three dimension with minimal surface forming a tightly packed structure with bicontinuous domains of water and lipid. There are three different proposed phases that these cubic structures can be in: the P-surface, G-surface and D-surface for primitive,

gyroid A gyroid is an infinitely connected Triply periodic minimal surface, triply periodic minimal surface discovered by Alan Schoen in 1970. It arises naturally in polymer science and biology, as an interface with high surface area. History and pr ...

and diamond structures respectively. This variation in structure allows for cubosomes to be the ultimate drug delivery system due to its ability to maintain the structural integrity of the ingredients that it carries. The uses of cubosomes are still being researched but they range from systems for efficient drug delivery into specific body systems to stabilizing and producing palladium nanoparticles.

Uses

For most fluids and some homogenous solid materials, like gels, diffusion is the same in all directions and characterized by the same diffusion coefficient number. This property is called isotropicity which gives cubosomes the ability to be used in biological tissues which are highly structured and typically have different diffusion coefficients along different directions (anisotropic). Because of advantages such as the unique structure of the cubic phase and its resemblance to biological membranes as well as

biodegradability Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...

of lipids, cubosomes are a great tool for drug delivery system. In addition, the bicontinuous cubic liquid crystalline phase (cubic phase)’s tortuosity is useful for slowing down diffusion as shown by Higuchi’s square root of time release kinetics. Capability to encapsulate hydrophilic, hydrophobic, and amphiphilic substance, being simple to prepare, and all the aforementioned qualities give cubosomes a property that can be used in controlled transport applications as drug delivery vehicles.

References

{{reflist, 30em Liquid crystals Colloidal chemistry