Nanoparticles disguised as erythrocytes will destroy cancer cells
Researchers at the University of California at San Diego, working under the guidance of Professor Liangfang Zhang, have developed a new method of masking therapeutic nanoparticles under red blood cells. This allows nanoparticles to avoid collisions with the immune system and deliver anticancer drugs directly to the tumor.
The new method consists in isolating erythrocyte membranes and wrapping them around biodegradable polymer nanoparticles loaded with a therapeutic cocktail of small molecules. The size of the nanoparticles does not exceed 100 nanometers, which roughly corresponds to the size of the virus.
The figure on the right shows a schematic image of a nanoparticle covered with an erythrocyte membrane and its image obtained using transmission electron microscopy.
Nanoparticles disguised from the immune system have already been successfully used to deliver chemotherapy drugs to cancer tumors. Usually artificial materials, such as polyethylene glycol, act as camouflage, prolonging the life of nanoparticles in the body from a few minutes to several hours.
According to Professor Chzan, the erythrocyte membrane provided circulation of nanoparticles in the body of laboratory mice for almost two days. Moreover, the use of the patient's own erythrocyte membranes negates the likelihood of an immune reaction to the administration of the drug.
On the left, the image obtained by scanning fluorescence microscopy demonstrates the integrity of nanoparticles disguised by the erythrocyte membrane (green) after their penetration into the cancer cell. The polymer nuclei of the nanoparticles are marked with red dye, and the cancer cell is blue.
The next stage of the study is to develop a method for creating nanoparticles disguised as erythrocytes in quantities sufficient for clinical use. The researchers also plan to learn how to supply the surface of such biomimetic nanoparticles with molecules that selectively bind to tumor cells, and to improve the method of filling the nuclei of nanoparticles in such a way that several drugs are delivered to a malignant cell at once.
Chzan notes that the possibility of simultaneous use of several drugs is extremely important, since with monotherapy, cancer cells often acquire resistance to the drug used. The combination of drugs will turn the nanoparticle into a kind of bomb for the instant destruction of a cancer cell.
Article by Che-Ming J. Hu et al. Erythrocyte membrane-camouflaged polymeric nanoparticles as a biomimetic delivery platform was published on June 20 in the preliminary on-line version of Proceedings of the National Academy of Sciences.
Evgeniya Ryabtseva
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of UC San Diego:
Nanoparticles Disguised as Red Blood Cells Will Deliver Cancer-Fighting Drugs.
22.06.2011