Dr. Zhen Gu and his team of international researchers at NC State, UNC, and China Pharmaceutical University have developed a drug delivery technique using graphene strips as “flying carpets” to deliver two anticancer drugs sequentially to cancer cells. “These drug-rich graphene strips are introduced into the bloodstream in solution, and then travel through the bloodstream like nanoscale flying carpets,” explains Dr. Zhen Gu. Each drug targets the distinct part of the cell where it will be most effective. TRAIL, an anticancer protein, can serve as an active targeting molecule to bind directly to the surface of cancer cells. It is most effective when delivered to the external membrane of a cancer cell. The second drug, doxorubicin (Dox), is most effective when delivered to the nucleus of a cancer cell. Once in the bloodstream, the graphene strips use leaks in nearby blood vessels to penetrate the tumor. When the strip comes into contact with a cancer cell, receptors on the surface of the cell latch onto the TRAIL. Enzymes on the surface of the cancer cells sever the peptides linking the TRAIL and the graphene, which allows the cancer cell to absorb the Dox and leaves the TRAIL on the surface, beginning a process to trigger cell death.
“We’ve demonstrated that TRAIL itself can be used to attach a drug delivery system to a cancer cell, without using intervening material – which is something we didn’t know,” Gu says. “And because graphene has a large surface area, this technique enhances our ability to apply TRAIL to its target on cancer cell membranes.”
The paper, “Furin-Mediated Sequential Delivery of Anticancer Cytokine and Small-Molecule Drug Shuttled by Graphene,” was published in early view online Dec. 15 in Advanced Materials. Lead author of the paper is Dr. Tianyue Jiang, a former graduate student in Gu’s lab who is now on faculty at Nanjing Tech University. The co-corresponding author is Dr. Ran Mo, who is also a former postdoctoral researcher in Gu’s lab who is now on faculty at CPU. Co-authors include Wujin Sun, a Ph.D. student in Gu’s lab; Qiuwen Zhu, a Ph.D. student at CPU; Nancy Burns, a Ph.D. student at NC State; and Dr. Saad Khan, Alcoa Professor of Chemical and Biomolecular Engineering at NC State.
UNC School of Medicine’s weekly newsletter Vital Signs has published a feature article about this promising development in the field of cancer treatment.