Liposome Research Paper

There are a number of diseases and medical problems which can be treated by taking different routes. It has become possible to treat certain conditions by delivering drugs or nutrients to the body with the help of liposomes. Liposomes are artificially engineered vesicles within a lipid bilayer. (Lee, 2006) There are various methods by which liposomes can deliver the needed substances. One of these ways is to create a PH gradient between the solution and the liposome. As the pH neutralizes the drug is able to diffuse across the membrane into the liposome and will eventually diffuse into the cells once it is within the body. (Bertrand, Bouvet, Moreau, & Leroux, 2010) Researching which factors affect the amount of a drug within the liposome and
the efficiency of delivery will aid to treat patients with pulmonary and cardiovascular problems more effectively. The amount of Rifampicin (RIF) entrapped within a liposome is important to the dosages that are possible.
The type of liposome used does not make a difference in the percent of RIF entrapped but the type of lipid used does. Phosphatidycholine (PC) based lipids entrap significantly less RIF than saturated lipids. When Chol is used within the lipid it will displace the RIF causing the amount of RIF in the liposome to decrease. (Marco, Mourtas, Klepetsans, Fadda, & Antimisiaris, 2007)After nebulizing the liposomes the nebulizing efficiency was 70% or higher for all liposomes. The only significant difference was that 50%-mol Chol distearoyloglycero-PC (DSPC) had a nebulization efficiency of 32-43%. This finding made it clear that rigid liposomes are not ideal for nebulization. (Marco et al.,
2007) Cardiovascular drugs lead to over 1 million overdoses annually in the United States and utilizing liposomes which deliver drugs to counter the effects would be a good option. Another possible treatment uses injections of fat emulsions but there are numerous complications and problems with this type of treatment. (Bertrand et al., 2010) For this reason, liposome-based treatment would be much more beneficial but first the type of liposome that works best must be decided upon. Using a liposome with a pH gradient has proven useful for entrapping weak basic drugs. The internal pH of the liposome and the buffer concentration were the two factors which affected the entrapping efficiency the most. A pH of 3 was found to be the optimal acidity as it provided a high entrapping efficiency, stability, and did not lead to a significant amount of acid-catalyzed phospholid hydrolysis. Furthermore, the amount of drug that was captured increased in relation to the concentration of citric acid up to 200mM. (Bertrand et al., 2010) In conclusion, the usage of liposomes to treat pulmonary and cardiovascular diseases could lead to better for these patients.
Nebulizing liposomes would allow for the delivery of drugs to be much more precise and would decrease the risk of side effects when compared to other methods. (Marco et al., 2007) Using liposomes with a pH gradient to treat an overdose of cardiovascular medications would have lesser side effects than fat emulsion injections. The pH gradient would entrap the drug as the acidity level naturally neutralized. (Bertrand et al., 2010) Liposomes will be a very useful treatment option for a large range of problems in the near future as it is researched
further.

References:

Bertrand, Nicolas, Celine Bouvet, Pierre Moreau, and Jean-Cristophe Leroux. "Transmembrane pH-Gradient Liposomes to Treat Cardiovascular Drug Intoxication." American Chemical Society 12 (2010): 7552-7558. Print.
Lee, R. J.. "Liposomal Delivery As A Mechanism To Enhance Synergism Between Anticancer Drugs." Molecular Cancer Therapeutics 5.7 (2006): 1639-1640. Print.
Zaru, Marco, Spyridon Mourtas, Pavlos Klepetsanis, Anna Maria Fadda, and Sophia G. Antimisiaris. "Liposomes For Drug Delivery To The Lungs By Nebulization." European Journal of Pharmaceutics and Biopharmaceutics 67.3 (2007): 655-666. Print.