Chemotherapy is So Barbaric

Here's some future speculation of how nanotechnology will someday make cancer treatment so much easier...

Nanoparticles specially engineered by Univ. of Central Florida Assistant Professor J. Manuel Perez and his colleagues could someday target and destroy tumors, sparing patients from toxic, whole-body chemotherapies.

Perez and his team used a drug called Taxol for their cell culture studies, recently published in the journal Small, because it is one of the most widely used chemotherapeutic drugs. Taxol normally causes many negative side effects because it travels throughout the body and damages healthy tissue as well as cancer cells.

The Taxol-carrying nanoparticles engineered in Perez’s laboratory are modified so they carry the drug only to the cancer cells, allowing targeted cancer treatment without harming healthy cells. This is achieved by attaching a vitamin (folic acid) derivative that cancer cells like to consume in high amounts.

Because the nanoparticles also carry a fluorescent dye and an iron oxide magnetic core, their locations within the cells and the body can be seen by optical imaging and magnetic resonance imaging (MRI). That allows a physician to see how the tumor is responding to the treatment.

The nanoparticles also can be engineered without the drug and used as imaging (contrast) agents for cancer. If there is no cancer, the biodegradable nanoparticles will not bind to the tissue and will be eliminated by the liver. The iron oxide core will be utilized as regular iron in the body.

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The process works like this. Cancer cells in the tumor connect with the engineered nanoparticles via cell receptors that can be regarded as “doors” or “docking stations.” The nanoparticles enter the cell and release their cargo of iron oxide, fluorescent dye and drugs, allowing dual imaging and treatment.“

Although the results from the cell cultures are preliminary, they are very
encouraging,”

Perez said.A new chemistry called “click chemistry” was utilized to attach the targeting molecule (folic acid) to the nanoparticles. This chemistry allows for the easy and specific attachment of molecules to nanoparticles without unwanted side products. It also allows for the easy attachment of other molecules to nanoparticles to specifically seek out particular tumors and other malignancies.

- Brewskie

Sniffing Out Cancer

Nanotechnology Now has this bit about the "cancer nose:"

An article describing Rotello and colleagues' new chemical nose method of cancer detection appears in the June 23 issue of the journal Proceedings of the National Academy of Sciences online.Currently, detecting cancer via cell surface biomarkers has taken what's known as the "lock and key" approach. Drawbacks of this method include that foreknowledge of the biomarker is required. Also, as Rotello explains, a cancer cell has the same biomarkers on its surface as a healthy cell, but in different concentrations, a maddeningly small difference that can be very difficult to detect.

"You often don't get a big signal for the presence of cancer," he notes. "It's a subtle thing."He adds, "Our new method uses an array of sensors to recognize not only known cancer types, but it signals that abnormal cells are present. That is, the chemical nose can simply tell us something isn't right, like a ‘check engine light,' though it may never have encountered that type before." Further, the chemical nose can be designed to alert doctors of the most invasive cancer types, those for which early treatment is crucial.

In blinded experiments in four human cancer cell lines (cervical, liver, testis and breast), as well as in three metastatic breast cell lines, and in normal cells, the new detection technique correctly indicated not only the presence of cancer cells in a sample but also identified primary cancer vs. metastatic disease.In further experiments to rule out the possibility that the chemical nose had simply detected individual differences in cells from different donors, the researchers repeated the experiments in skin cells from three groups of cloned BALB /c mice: healthy animals, those with primary cancer and those with metastatic disease. Once again, it worked. "This result is key," says Rotello. "It shows that we can differentiate between the the three cell types in a single individual using the chemical nose approach."

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Rotello says the chemical nose approach is so named because it works like a human nose, which is arrayed with hundreds of very selective chemical receptors. These bind with thousands of different chemicals in the air, some more strongly than others, in the endless combination we encounter.

The receptors report instantly to the brain, which recognizes patterns such as, for example, "French fries," or it creates a new smell pattern.Chemical receptors in the nose plus the brain's pattern recognition skills together are incredibly sensitive at detecting subtly different combinations, Rotello notes. We routinely detect the presence of tiny numbers of bacteria in meat that's going bad, for instance. Like a human nose, the chemical version being developed for use in cancer also remembers patterns experienced, even if only once, and creates a new one when needed.

For the future, Rotello says further studies will be undertaken in an animal model to see if the chemical nose approach can identify cell status in real tissue. Also, more work is required to learn how to train the chemical nose's sensors to give more precise information to physicians who will be making judgment calls about patients' cancer treatment. But the future is promising, he adds. "We're getting complete identification now, and this can be improved by adding more and different nanoparticles. So far we've experimented with only three, and there are hundreds more we can make."

- Brewskie