Iranian researchers produced pH-sensitive micelles based on monomethyl itaconate polymer, side chains of cholesterol and polyethylene glycol and studied their capability to release drug to be used as drug-nanocarriers in cancer treatment. The results of the research have applications in pharmaceutical industry, and they can reduce side-effects caused by anti-cancer drugs. Dr. Zhaleh Pourmoa’zzen, one of the researchers, explained about the purpose of the research. “Cholesterol is one of the structural elements in body cells, and it plays an important role in body metabolism. This natural lipid is biocompatible and biodegradable, and it is usually used in the modification of the properties of polymers and drug carrying nanoparticles to create hydrophobic properties in them due to its hard molecular structure and high hydrophobicity.” “On the other hand, polyethylene glycol 2000 is used as cross-linker to increase hydrophilicity of the polymer and to increase the micelles created by it in blood stream. Therefore, we tended to use monomethyl itaconate polymer, cholesterol, and polyethylene glycol (PEG) in the production of pH-sensitive micelles, and to study targeted drug delivery by using this drug nanocarrier,” she added. Results showed that the micelles containing cholesterol had noticeable stability. The grafting of PEG to the polymeric structure prevented hydrophobic molecules of the drug to get close to the surface layer of micelles by increasing hydrophilicity of micelle surfaces, and it kept the drug inside the core. The synthesized micelles are at nanometric scale, and taking into consideration the pH value of the media, drug release took place at constant rate in a time period of 50 hours. The drug nanocarriers released the desirable drug in targeted area considering the pH value of cancer cells (pH = 5.5). Results of the research have been published in details in Journal of Polymer Research, vol. 20, November 2013, pp. 294-305.