Production of hyperbranched drug-carrying polymers from citric acid monomers in Iran

Iranian researchers from Payam-e Nour University of Tabriz in association with researchers from Lorestan University succeeded in the production of biodegradable hyperbranched polymers that are compatible with human body temperature. The polymers are made of citric acid and glycerol monomers through dense polymerization method, and they can be used as drug-carrying nanoparticles in medical purposes, specially in cancer treatment. Since citric acid decomposes at its melting point, the polymerization of this monomer is not possible for the preparation of polymers and copolymers. Three various types of hyperbranched polymers were synthesized in this research with different ratios of citric acid and glycerol under the same conditions of temperature and time. The polymer is compatible with biological media, and it has numerous internal voids that enable it to carry drug. The presence of functional groups on the surface of the polymer results in the release of the drug to the target. The abovementioned polymers can have desirable application in the place of biological molecules. The hyperbranched polymers can be easily synthesized with very high molecular weight by changing two important parameters of reaction time and ratio of the monomer. The polymers are able to pass through cell membrane. Similar to dendrimers, the polymers have many functional groups and internal voids, so they are considered appropriate carriers of various medical molecules such as cancer treatment medicine, including cisplatin, through physical (capsulation) or chemical (coupling) methods. Results of the research showed that the production of hyperbranched polymer was cost-effective. Moreover, the dosage of anticancer drug capsulated with hyperbranched polymer was halved in comparison with that in free anticancer drug. Therefore, the side-effects caused by the anticancer drug reduced on healthy cells. The latest results of the research have been published in Journal of Applied Polymer Science, vol. 129, issue 6, 15 September 2013, pp. 3665-3671.