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 problem is with drugs designed to work from the inside is they have a short life. The drugs are often absorbed into cancer cells and become ineffective. For this reason, researchers wanted to find a means to lock the drug into the tumor for longer.
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.”