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What are Liposomes?

In the lab, liposomes have been used to transfer DNA into target cells.
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  • Written By: Mary McMahon
  • Edited By: O. Wallace
  • Last Modified Date: 02 October 2014
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Liposomes are microscopic vesicles developed in a laboratory environment. Each liposome has an outer wall comprised of lipids similar and sometimes identical to those which compose the cell wall, allowing liposomes to interact directly with cells. There are a number of applications for liposomes, ranging from targeted delivery of medications to specific areas of the body to genetics research in the laboratory.

The liposome was first developed by a British researcher, Alec Bangham, in 1961. According to legend, he was experimenting with new laboratory equipment, and he made a noted observation about the structure of the cell wall and developed liposomes at the same time. Numerous other researchers have worked with these structures since, developing new information about them along with potential uses.

Natural cell membranes, as Bangham learned, are made from a double layer of phospholipids. Each phospholipid has a head which is drawn to water and a tail which is repelled by it, and in the case of the cell wall, the heads and tails form a two-layered circle around the cell. The heads face out into the body, while the tails connect with each other, allowing the heads of the other side to face into the cell. The same holds true of the walls of liposomes.

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The inside of a liposome can be packed with medication, vaccines, DNA, and a variety of other substances. When liposomes are introduced into the body, they can mesh with various cells, delivering their payload. One advantage to using liposomes is that they can be used to shield delicate cells from harsh drugs, and they are believed to be nontoxic, so the delivery method for the drugs should not cause a reaction.

In the lab, liposomes have been used to transfer DNA into target cells. This allows researchers to use liposomes rather than viral or bacterial vectors to make genetic modifications, which carries some distinct advantages. The lab experiments also suggest that liposomes could be used to deliver gene therapy to patients, with the cells bringing in replacement DNA for damaged material, up to entire chromosomes.

In addition to being used in science and medicine, the liposome also shows up in cosmetics. These structures are especially effective for moisturizers, increasing the strength and efficacy of such products considerably. Like many developments which started in the scientific community, they are also used as an advertising point in ingredient lists, as some cosmetics consumers prefer products which are associated with science and medicine.

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Discuss this Article

Alchemy
Post 7

@cougars- It makes total sense that liposomes are part of the lipid family. This explains why moisturizers and make-ups use liposomes as an added ingredient.

Before reading this article and the discussion posts, I was clueless about liposomes and the likes. I had to learn more about the function of these for biology, and the article and these discussions helped me relate it to real-life applications better than my text. I feel like I have a better understanding of liposomes and lipids than I did a few minutes ago. Now if someone could tell me what multilamellar liposomes are, I would be ecstatic.

cougars
Post 6

@Amphibious54- Liposomes are actually a type of lipid and are closely related to the other supplements you said you take. Lipids are not necessarily fats; rather they include fats, waxes, sterols, and fat-soluble vitamins among many other things. The fatty acids that you supplement with are lipids, and can improve cardiovascular health. Some prescription drugs are actually just highly refined fatty acids from the omega fatty acid group.

Other lipids that people may supplement with regularly are things like fat soluble vitamins. These are vitamins A, D, E, and K. The fact that they are fat soluble lipids explains why they are found in starchy foods like carrots and bananas, fatty meats, and dairy products.

Other common lipids that are sometimes supplemented are things like steroids and sterols. Androgens, testosterone, and androsterones are the illegal lipids that you likely have to look out for in your supplements. In some cases, these sterol lipids are added to sports supplements legally, but may be banned in collegiate or professional sports. These lipids naturally occur in the body, but they can actually be detrimental to one's health if they are abused.

Glasshouse
Post 5

@PelesTears- I read an article discussing research on Science Daily about a week ago, and preliminary trials have shown that lab engineered liposomes can block HIV infection. I think this treatment would be used more as a short-term vaccine or one time use application rather than a treatment or cure. From what I read, it was being discussed as a cost-effective preventative treatment for developing countries.

The idea behind the charged liposomes discussed in this article can be quite expensive, but a liposome does not always need to be filled with drugs.

In the case of this treatment, the empty liposome is intravaginally injected into the body where it coats the vaginal wall. This significance in this is that it can be applied much like a spermicidal lubricant before intercourse. The empty liposomes have proven to inhibit HIV infection in culture tests, and their safety has been demonstrated in laboratory mice.

The benefit of this treatment is that the liposomes themselves are very cheap to manufacture. The drugs inside of liposomes are what are costly. This treatment can also help protect the world's women from HIV infection in places where men rarely use condoms, or condoms are unavailable.

The treatment has the potential to put the decision for safe sex into the woman's hands in places where women do not have the same status as men.

Amphibious54
Post 4

Correct me If I am wrong, but aren't liposomes simply fats? I am not that well versed in chemistry or biology, but after reading this article, a liposome sounded a lot like a fat particle.

This being the case, I can see why they are so helpful in treating diseases. I take certain fatty acids with similar names to lipids and liposomes that supposedly help maintain a healthy heart, joints, and muscles. Additionally, a number of my sports supplements, protein shakes, and the likes say they contain things like lipids.

I am no doctor, but I spend a lot of time conditioning for college sports, which makes me have to be conscientious of ingredients in supplements. I run across similar sounding substances in the supplements I take and I would like to know if they are in the same classification of liposomes as the ones discussed in this article.

GlassAxe
Post 3

@PelesTears- (Continued) These drugs, like paclitaxel, work by interfering with the reassembly of the tubule structures, thus inhibiting cancerous growth.

The active drug in these types of treatments are delivered through the little lipid particles, liposomes, that this article so clearly explained. These little lipids bind themselves to the cells that line blood vessels, preventing blood vessel growth, this prevents the growth of the tumor by preventing the tumor cells from receiving adequate nutrients, thus contributing to the destruction of the tumor.

I am not sure how successful these treatments are, but I think they are used as important parts of many cancer treatments. As for how they affect patients with HIV, I am not sure. I would assume that the idea is similar, but the system is designed for the specific delivery needs for HIV.

GlassAxe
Post 2

@PelesTears- Liposomes treatments for cancer do exist. When cells divide, the tubule structures inside the cells need to disassemble and re-organize themselves in very precise ways. In a cancerous cell, growth is out of control, so treatments look to stop or slow growth. Liposomal mitotic inhibitors used in some chemotherapy treatments play the role of cell growth disruptors.

PelesTears
Post 1

What type of treatments can liposomes be used for? I am writing a paper on the treatment methods for HIV and cancer and someone told me I should look into liposome treatments. Can someone give me a basic understanding of how these treatments work? I honestly have no idea where to start with this treatment and I figure if I knew a little more about the treatments, I would have a better idea about how to research my topic.

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