June 02, 2010
Nanosponges Against Cancer

Nanosponges carrying cancer chemo-therapy drugs selectively target cancer cells in mice.

When loaded with an anticancer drug, a delivery system based on a novel material called nanosponge is three to five times more effective at reducing tumor growth than direct injection.

That is the conclusion of a paper published in the June 1 issue of the journal Cancer Research.

"Effective targeted drug delivery systems have been a dream for a long time now but it has been largely frustrated by the complex chemistry that is involved," says Eva Harth, assistant professor of chemistry at Vanderbilt, who developed the nanosponge delivery system. "We have taken a significant step toward overcoming these obstacles."

So far these nanosponges have only been tested in mice.

The nanosponges work in a manner similar to viruses in that they bind to surface antigens on target cells.

To visualize Harth's delivery system, imagine making tiny sponges that are about the size of a virus, filling them with a drug and attaching special chemical "linkers" that bond preferentially to a feature found only on the surface of tumor cells and then injecting them into the body. The tiny sponges circulate around the body until they encounter the surface of a tumor cell where they stick on the surface (or are sucked into the cell) and begin releasing their potent cargo in a controllable and predictable fashion.

To make this delivery vehicle work well researchers must come up with antigens on the surface of each instance of cancer that are not found much in the rest of the body. Does anyone know whether cancer cell outer surfaces can be expected to contain unique antigens that are distinct from those found on the surfaces of non-cancer cells? Is this even a question that has a known answer yet for most types of cancer?

Share |      Randall Parker, 2010 June 02 11:34 PM  Biotech Cancer

Brett Bellmore said at June 5, 2010 4:45 AM:

It's certainly the case when it comes to the B cell lymphoma I had. That's why the synthetic antibody that was part of my treatment was so effective. I could see this as a way of delivering some of the other components of the chemo, but there is one problem: One of the reasons you use multiple drugs in chemo is to deal with the genetic diversity of cancer cells, you don't want to miss a cell that might be particularly resistant to one of the drugs.

If all the drugs were being delivered on the basis of binding with a particular antigen, any cell that didn't exhibit that antigen would be untouched. Not good.

Now, if you could deliver chemo systematically, while using something like the nano-sponge to deliver an antidote to the chemo to specific cell types which are not involved in the cancer, but particularly hard hit by the chemo, that could be useful. Maybe something to protect you from peripheral neuropathy, a common chemo side effect.

But, no, it's my understanding that cancer cells are not generally expected to exhibit different antigens, or else the immune system would cope with cancer better. Different proportions of them, perhaps.

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