CARBON NANOCOMPOSITES IN MEDICINE: GRAPHENE AND POLYGRAPHENE AS POSSIBLE DRUG DELIVERY VEHICLE FOR INTESTINAL ONCOLOGY

Abstract

The paper considers one of the most important directions in modern pharmacology - targeted delivery of medicines, namely the directed transport of medicinal substance to given area of body, which is realized with help of carriers, which, as a rule, have sizes of tens or hundreds of nanometers, different nature and chemical structure. The delivery of antitumor drugs using nanoparticles is being discussed. Immobilization of drugs on nanocarriers makes it possible to increase their bioavailability. Various graphene derivatives - graphene oxide (GO) and reduced graphene oxide (RGO) - are being tested as carriers for drug delivery. There are several approaches for targeted drug delivery in oncology. The first, simple one is the attachment of both low– and high-molecular preparation to the surface of the carrier directly. The drug doxorubicin is firmly bound to surface of graphene oxide and is released only in acidic environment of tumor. The second, more complex method is to attach to surface of carrier not only active substance, but also guiding molecules - ligands. Sometimes ligand itself can be a drug at the same time. Polygraphene (PG) is an original modified analogue of thermally split graphite, obtained in the form of new form of expanded graphite, after repeated chemical modification and thermal activation, it is reduced to the characteristics of a layered material with stacks of carbon monolayers of smaller multiplicity (from 5 to 50), up to single sheets of graphene. The results of tests of PG as an effective basis for the immobilization of enzymes are presented, in particular, on the example of antitumor enzyme L-lysine-α-oxidase. These data indicate prospects of possible biomedical use of PG in oncology, namely, in treatment of intestinal cancer. Modified forms of graphene and polygraphene should be considered as new carrier of drugs.