Vesosome

Key takeaways

Vesosome belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Vesosome to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Vesosome from memory before moving on to harder problems.

Reference excerpt

A vesosome is a multi-compartmental structure of lipidic nature used to deliver drugs. They can be considered multivesicular vesicles (MVV) and are, therefore, liposome-derived structures.

Description Vesosomes consist of one or more bilayers enclosing an aqueous core that contains unilamellar vesicles that function as internal compartments which contain the drug and which can vary in composition from each other. The external bilayer defines the lumen, limits emission of the vesicle contents, and protects the vesicle contents from degradation due to lipolytic enzymes. Its unique properties enable localized drug delivery to specific parts of the body and extend the duration of drug effect. Vesosomes are relatively straightforward to produce and they offer the flexibility to deliver multiple drugs within a single carrier, which has been shown to confer important advantages in chemotherapy. Internal vesicle diameters range from 20-500 nm and vesosome diameters range from about 0.1 micron to more than 1.0 micron.

Historical background Shortly after the first description of liposomes, by British haematologist Alec D Bangham in 1961 (published 1964), at the Babraham Institute, in Cambridge, scientists first started to contemplate the possibility of employing them as transportation systems in the blood stream. Since then, there have been many advances in this area, and as of 2008 there were 11 clinically approved liposomal drugs targeting a variety of pathological conditions and illnesses, including fungal infections, hepatitis A, influenza and certain cancers. Now, scientists plan to take full advantage of the 40 years of progress in liposome development to enhance this transportation system by employing vesosomes.

Design and construction

Vesosome multicompartment structure encapsulates unilamellar liposomes within a second bilayer. For this purpose, it is necessary to form bilayers that can be opened and closed at will, without disrupting the inner content. This is achieved by adding ethanol to a variety of saturated phospholipids in the gel phase, which drives interdigitation of phospholipids bilayers and subsequent fusion of small vesicles to form flat bilayer sheets. These are steady to removal of the residual ethanol until heated above the lipid chain melting temperature (Tm). The bilayers become flexible, and the sheets spontaneously close on themselves to form unilamellar vesicles. During the closure, the sheets can entrap whatever is around in suspension. By adding the vesicles aggregates including drug-loaded vesicles to the pelleted sheets before heating the mixture, encapsulation is carried out to form vesosomes. Vesosome structure has taken advantage of the progress in liposome development as steric stabilization, pH loading of drugs (it is loaded by pH gradient), and intrinsic biocompatibility (it can be modified with a variety of agents, for example to specifically target a disease site, or promote adhesion or fusion).

Applications A wide of molecular structures can be encapsulated in vesosomal vesicles, such as proteins with complex three-dimensional structures or condensed DNA. The most common use is to fill the vesosome’s vesicles with certain drugs that are going to be delivered in a particular area. Due to the small size of the vesosome and its good protection of the inner vesicles, it can be used in various cases, doing different functions. If suitable receptors are included in the outer lipid bilayer of vesosomes during their preparation, then they are able to locate to inflamed areas. Once in the inflamed area, such vesosomes will deliver an anti-inflammatory substance from its vesicles though a pH gradient. Vesosomes that localise to tumours have also been demonstrated. They can be used to create, in a positioned area, a different nano-environment (considering that vesosome size is about 50 - 200 nanometres) either by altering the pH or the concentration of a particular substance.

References

External links Kisak ET, Coldren B, Evans CA, Boyer C, Zasadzinski JA.The Vesosome - A Multicompartment Drug Delivery Vehicle Retrieved 25 November 2012 Boyer C, Zasadzinski JA Multiple Lipid Vesicle Compartments Slow Vesicle Contents Release in Lipases and Serum Retrieved 25 November 2012 Vesosome: A Versatile Multi-Compartment Structure For Targeted Drug Delivery Retrieved 25 November 2012

Worked examples

Example 1 — a first encounter with Vesosome

Start with the simplest possible case. Write down what Vesosome claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Vesosome before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Vesosome ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Vesosome

In research: Vesosome appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Vesosome in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Vesosome is common in secondary-school and first-year university syllabi. It links to neighbouring topics Drug delivery devices, so understanding it makes those chapters shorter.
In everyday life: Look for Vesosome outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Vesosome in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Vesosome means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Vesosome out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Vesosome in simple terms?

A vesosome is a multi-compartmental structure of lipidic nature used to deliver drugs. They can be considered multivesicular vesicles (MVV) and are, therefore, liposome-derived structures.

Why does Vesosome matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Vesosome?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Vesosome.