04 September 2013

Cancer treatment: hydrogel is more effective than a "pure" drug

Hydrogels attack cancer targets

ChemPort.Ru based on materials from Chemistry World: Hydrogel treatment targets tumoursHydrogels of taxol, an antitumor drug, injected directly into the tumor, have demonstrated greater effectiveness in restraining tumor growth compared to intravenous injections of the same drug, and with a dosage four times higher.

Taxol is used to treat many lines of cancer, including breast cancer, lung cancer and ovarian cancer. Usually taxol is administered intravenously every three weeks of the course of therapy. It may take several hours to achieve the required dosage of the drug with this method of delivery.

Hydrogels have great potential in terms of reducing the frequency of taking a chemotherapeutic drug. They can maintain a high concentration of the drug where it is required. The drug is released in a controlled and reliable manner. However, the synthesis of such hydrogels is not an easy task, and is also accompanied by low yields.

The group of Zhimou Yang from Nankai University in China successfully mastered the synthesis of taxol hydrogels according to a simplified scheme. The hydrogel obtained by the researchers contains taxol bound to folic acid. Folic acid makes it easier to recognize a tumor, since most cancer cells have receptors for folic acid. Thus, hydrogels will evenly release the taxol contained in them due to the hydrolysis of ester bonds directly in the tumor tissue.

Yang says that the solid-phase peptide synthesis they developed to convert the initial reagent into a conjugate is the key to an improved synthesis strategy. Folic acid and taxol conjugates can be obtained in only two stages, with a yield of about 40%, and they do not require complex purification steps. The new approach is a significant modification of their previous work, which required 5 stages, and the yield was less than 10%.

Joel Collier, an expert in the field of synthetic biomaterials from the University of Chicago in the USA, explains that gelation not only ensures the prolonged release of the drug, but also contributes to its delivery and retention in the tumor. Collier adds that because of the excellent control over the release kinetics of such materials, this strategy could be very useful, and not only for cancer therapy.

Vitaliy Khutoryansky, a specialist in pharmaceutical materials from the University of Reading in the UK, considers the concept of creating taxol-containing hydrogels interesting. However, he says that the injection of a liquid dosage form of taxol, which turns into a gel in situ by increasing the concentration of glutathione in tumor cells, could be more appropriate for medical use.

Extending this approach to other drugs and other in situ gelation systems looks like a promising direction for further research.

The article by Yang et al. Disulfide bond reduction-triggered molecular hydrogels of folic acid–Taxol conjugates is published in the journal Organic & Biomolecular Chemistry.

Portal "Eternal youth" http://vechnayamolodost.ru04.09.2013

Found a typo? Select it and press ctrl + enter Print version