Nanotechnology to Find the Right Drug for Cancer, Without Poisoning the Patient

A cancer drug may work wonders in one patient and do nothing for another. An Israeli engineering team is now suggesting a novel way to skip the painful, sometimes deadly, trial-and-error stage.

Ruth Schuster
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Dr. Avi Schroeder, chemicals engineer, who used an engineering approach to resolving the deadly problem of matching cancer drugs to patients.Credit: Courtesy of the Technion
Ruth Schuster

Cancer drugs are notoriously toxic and worse, while a drug might work on one patient, it won’t on another. Now an Israeli nanotechnology engineer says he’s cracked the problem bedeviling cancer patients and their doctors: personalizing the identification of effective cancer medicine, quickly, efficiently and affordably, without subjecting them to painful – even fatal – trial and error.

There are some 200 drugs for cancer on the market. No doctor can know in advance if a given drug will work on a given patient. Unable to predict which might work best on a given patient, doctors give him one drug after another, based on statistics: The therapy protocol is therefore to start with a drug with a good track record; if it doesn’t work they try another.

This process is bad for the patient, as cancer drugs can have horrible side effects, leaving him weaker; and for the HMO, since they’re also expensive. Moreover, while testing this and that drug on these unwell, reluctant guinea pigs, precious time is wasted and the patient just gets sicker, both from the disease and from the drugs.

By the time something is found that works, it may be too late, explains Dr. Avi Schroeder of the Technion-Israel Institute of Technology’s chemical engineering faculty – specifically at the Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies. “Being an engineer, I thought of an engineering approach to prescreen drugs on a personal basis before we begin a treatment cycle.”

Thus Schroeder and his research team came up with a fast, painless, personalized low-cost way to test multiple drugs at once, based on nanoparticles, each containing a miniscule dose of a single drug, “bar-coded” using a sequence of DNA.

The principle is like testing for an allergy by scratching the skin and applying a tiny amount of the allergenic agent, to see if the patient’s skin reacts. In this case, the goal is to give the patient a battery of cancer drugs in miniscule doses – and see which actually reach the tumor, penetrate the cancer cells and kill them.

Personalizing medicine: Genes aren’t everything

Most attempts to personalize cancer therapy are based on analyzing the patient’s genetic makeup, and trying to match him or her with treatments likely to be effective.

“Genetics play a very important role,” Schroeder says. “But we don’t have the entire picture of genetics and epigenetics, which dictate which drug will work in each patient and which won’t. There may also be non-genetic factors – environmental factors, or factors inside the body that we haven’t identified yet that may play a role in the efficacy of one drug compared with another. Clinically, several studies are suggesting today that genetics aren’t everything when trying to predict which drugs will work on each patient.”

His process isn’t toxic because they test “very, very small” amounts of drug inside each nanoparticle, Schroeder explains.

Nanoparticles containing barcoded drugs are formed and injected; they find the tumor and invade its cells; the tumor is then biopsied to see which drugs killed tumor cells and which didn't.Credit: Dr. Avi Schroeder, Courtesy of the Technion

It sounds expensive to create nanoparticles containing drugs barcoded with DNA. Schroeder hastens to reassure that the process of attaching a segment of DNA to each molecule of the drug is not expensive any more. “The DNA itself has become very cheap.”

These nanoparticles with the bar-coded drugs are injected into the patient’s bloodstream. They travel around the body and when they identify a tumor, the particles penetrate its cells through micro-fissures typical to cancer cells, and release the drugs into the cells.

Some of the drugs will work and kill the tumor cells. Others won’t. To find out which drugs were the most effective in that patient, according to Schroeder’s concept, the tumor is then biopsied. Cells are examined individually: They separate the living cells from the dead ones, to see which drug barcode is the most associated with killing cancer cells, and which are not.

Armed with this information, doctors can make clinical recommendations on an effective drug regime for the specific patient, based on testing his actual tissue, not general statistics.

And there you have personalized medicine based on nanoengineering. The patient is spared experiments with drugs that sicken him and don’t help, and the taxpayer is spared the cost of paying for that pleasure.

The Technion research, which focused on breast and skin cancer, aims to enable doctors to assess the treatment’s effectiveness within a week, dramatically improving the therapy process – and cancer patients’ quality of life. Testing has reached the preclinical stage, says Schroeder: Now they’re looking for financing to bring their work to market. “I believe most cancers can be treated with the drugs we have out there, plus the new drugs that will be developed,” he says.

And hopefully, armed with his method, doctors can figure out which will work before it’s too late.