Novel Oncologic Approach by Drug Trapping
Larry H. Bernstein, MD, FCAP, Curator
LPBI
Tim Sandle, PhD just reported on this interesting and novel method of chemotherapy for cancer.
Fighting cancer by trapping drugs in tumors
A research group have developed a novel means to fight cancer. Because anti-cancer drugs only work for a limited time, the new method succeeds in trapping the drug inside the tumor so it works for longer.
Cancer drugs vary in their mechanism of activity. Some are intended to attack the tumor from the outside whereas others are designed to attack the tumor from within. An example of the latter is the drug cilengitide which affects blood veseels and it is intended to cut-off the nutrient supply to cancerous cells. It is with medications designed to work from the inside that the new research as focused on.
The process of doing so involves creating pockets or ‘depots’, of microscopic sizes, to enable anti-cancer drugs to remain trapped inside tumors. To do this they developed nanocarriers, to wrap the anti-cancer drug into. The nanocarrier is covered with even smaller nanoscpasules composed of hyaluronic acid gel. The capsules contain an enzyme, and they are injected into the blood stream.
On reaching the tumor site, the capsules dissolve as a consequence of an enzyme located on the tumor surface. The carriers are then deposited inside the tumor. The depot is larger enough to prevent absorption by the cancer cell. The nanocarrier is designed to breakdown slowly and to produce a slow-release of the anti-cancer drug within.
The feat of biomedical engineering was tested out on mice. Here it was found the anti-cancer medication was 10 times more effective against tumors, increasing the shrinkage rate, when compared to the same drugs administered conventionally.
The study was designed as a “proof of concept.” Having established this, further studies will be set up to test out the effectiveness of the method.
The research was conducted at two centers: North Carolina State University and the University of North Carolina at Chapel Hill. The research findings are published in the journal NanoLetters, in a paper titled “Tumor Microenvironment-Mediated Construction and Deconstruction of Extracellular Drug-Delivery Depots.”
SJ Williams, PhD
I wonder if they get the same effect as with the earlier attempts at producing either prodrugs linked to antibodies (like the ADEPT method) which did work except for some severe dose-limiting toxicities. The other phenomenon to consider is ‘bystander effect’ and if this approach produces such an effect or not. Irregardless increased distribution of drug is extremely important and would be nice to see in further studies if dose could be minimized.
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