Long ago, a Greek hero named Odysseus found a way to win the Greek war against Troy. By constructing and gifting a gigantic wooden horse, now known as the Trojan horse, the Greeks sought to formally admit their defeat. The gift, however, was a ploy to open the impenetrable city gates to the Greek soldiers while the Trojans were celebrating their perceived victory. Similar to the Trojan horse strategy, scientists have successfully taken the concept and applied it to cancer therapy. By coating anticancer drugs on the patient’s own platelet membranes, scientists can now develop treatment methods that allow the drug to remain in the body circulation for a while longer, and therefore attack cancer cells for much longer periods of time.
The process behind this is simple: first collect a portion of the patient’s blood, isolate the platelets, then break apart the platelets to extract the platelet membrane. Once extracted, the membranes are then placed into a solution of a drug of interest. In this experiment, the scientists used the anticancer drug called doxorubicin, which inhibits a protein necessary for DNA replication. This drug works by stabilizing Topoisomerase II, one of the proteins used in DNA replication, so that it cannot interact with DNA. When the protein enters this state of stability, it’s almost impossible to restart the process, thus the cell stops dividing. Since cancer lethality is attributed to the uncontrollable cell division of cells gone wrong, stopping cancer cells from dividing essentially has the same effect as curing cancer.
Through compressing and forcing the drug into the patient’s collected platelet membranes, the doxorubicin is coated with a pseudoplatelet outer covering, ready to be used. When cancer cells encounter the pseudoplatelets, they then take up the drug and begin to break apart the drug-coated pseudoplatelet, which releases doxorubicin into its center. In addition to the unique delivery system posed by the pseudoplatelet system, coated drugs typically circulate in the body for up to 30 hours instead of the usual six hours without the outer pseudoplatelet membrane. Since cancer cells take up pseudoplatelets extensively, the therapy would be concentrated at the tumor site.
The development of this drug delivery technique ultimately has a huge implication for science; it can be used to treat a multitude of diseases that require selective and precise treatments. One example could be the treatment of atherosclerosis by delivering plaque dissolving drugs coated with pseudoplatelet membranes to be taken into the plaque buildup site where platelets normally go. Another treatment could possibly be the treatment of open wounds or cuts. Coated antibiotics with platelet membranes would cycle through the body until it is directed the injury site, thereby reducing the chance of infections.
Feature Image Source: Human blood with red blood cells, T cells (orange) and platelets (green) by ZEISS Microscopy
