Researchers have developed a means of coating anticancer drugs with membranes made from a patient's own platelets, making it possible for the drugs to last longer in the body and target both circulating tumor cells and primary cancer tumors.
In a study published in the journal Advanced Materials, the researchers elaborated on the two distinct advantages of utilizing platelet membranes to encapsulate anticancer drugs. First, cancer cell surfaces are attracted to platelets, meaning they stick to each other, and second, the drug is not identified as a foreign object because it is covered in a material that came from the patient's own body, which is what allows it to last longer in the bloodstream.
By combining these effects, the anticancer drug is not only able to more effectively attack the main site of a tumor but can find tumor cells in the blood stream as well, preventing them from taking hold and developing.
The process starts by taking blood samples from the patient (in this case, a mouse). Platelets from the sample are then isolated and treated to separate platelet membranes. These are placed in a solution containing nanoscale gel with doxorubicin, an anticancer drug. The solution is compressed, which forces the gel into the membrane and results in nanoscale spheres with platelet membranes wrapped around doxorubicin cores. The spheres are further treated with TRAIL, another anticancer drug, which is highly effective at targeting cell membranes around cancer cells.
When a pseudo-platelet comes in contact with a tumor, P-Selectin proteins from the platelet membrane start binding to CD44 proteins on cancer cell surfaces, which locks the two together. Afterwards, TRAIL on the surface of the pseudo-platelet begins attacking the cell membrane of the cancer cell. The larger cancer cell then swallows the pseudo-platelet, its acidic environment within breaking down the pseudo-platelet's membrane. This then frees up the doxorubicin core, which attacks the cancer cell from within and destroys its nucleus.
Further tests are needed but the researchers believe it is possible to use the system to deliver other drugs as well, like those for cardiovascular disease, where platelet membranes can aid in bringing a drug to a relevant site in the body.
The study was supported by NC TraCS. Authors include: Zhen Gu, Hunter Bomba, Chao Wang, Chengen Qian, Wujin Sun and Quanyin Hu.