Nanomedicine Could Revolutionize Cancer, HIV Research

POTOMAC, Md. — For Esther Chang, treating cancer using nanomaterials is like delivering a package by FedEx: what you need goes right to your door.

“They have the address,” she said. ​“The difference between a FedEx truck and a crop duster is that airplanes have no address.”

In medicine, of course, the crop dusters are traditional treatments that circulate throughout the body — often with toxic side effects. Now, with nano-based treatments — new medicines developed for super-small ​“nano” particles that acquire new super-properties — that target tumors directly, Chang said, so much more is possible.

“In any type of therapy, if it’s not targeted, it’s not going to be beneficial,” said Chang (pictured), a professor at the Lombardi Comprehensive Cancer Center at Georgetown University. ​“The field is moving very rapidly. People are rapidly realizing that targeting is a must. It’s not a luxury.”

Chang is also the president of the American Society for Nanomedicine. The group held its second annual conference here last week in concert with the National Institutes of Health’s Office of AIDS Research and the Division of AIDS at the NIH’s National Institute of Allergy and Infectious Diseases. The goal of the conference was to bring experts in nanomedicine — many of them cancer researchers and entrepreneurs — together with government scientists and policy experts working on HIV prevention, treatment and vaccines.

Chang and others at the conference said advances in nanomedicine could transfer easily between cancer and HIV research, especially when it comes to therapies that use super-small nanomaterials to deliver drugs to specific parts of the body, or even stimulate the body’s own immune system to fight disease.

Because these nanoparticles are at the molecular scale, they can get into cells directly, maximizing a drug’s effectiveness. Chang and others are excited at the flexibility these materials promise.

​“This platform, it’s modular. It’s like Legos,” Chang said. ​“You put parts together to do different things. I use a different address, and it’s a different payload.”

Many cutting-edge ideas are still in the embryonic stages, but they are tantalizing. Darrell Irvine (pictured), an MIT professor, discussed recent work in his lab that attaches drug-loaded nanoparticles to T‑cells, which can help fight disease through the immune system, along with a chemical that helps the T‑cells thrive. In mice, Irvine said, the therapy caused an explosion of T‑cells, which destroyed tumors and dramatically outperformed more traditional therapies.

Another new method, which has been run through early clinical trials, uses a biodegradable nano-based delivery system to target solid tumors — which don’t respond well to existing therapies — with gene therapy. Kathleen Pirollo, the Georgetown researcher who presented the research, said the particles accumulate in the tumors, but not in the normal surrounding tissue.

The device’s first human trial showed strong results with minimal side effects, she said. And it performed well in mice, when combined with other therapies such as radiation, an eventual goal for human treatment as well.

HIV researchers are also using these emerging technologies. Howard Gendelman, at the University of Nebraska Medical Center, is experimenting with nanoformulations of antiretroviral therapy, the common treatment for HIV infections. As with the cancer treatments, nanomaterials could help reduce the amount of drugs patients need to take, which could reduce the side effects of treatment, and eventually make life-saving therapies cheaper and therefore more widely available.

Nanomedicine has promise in the development of vaccines to fight HIV, too, both before and after infection. Julianna Lisziewicz, president of the biotechnology company Genetic Immunity, showed off the firm’s topical HIV vaccine, called DermaVir (pictured).

After a patient’s skin is exfoliated with a special sponge, patches containing the drug are applied. The nanoparticle that delivers the drug is like a pathogen, Lisziewicz said, and enters the body through a type of cell in the skin, then drains into the lymph nodes. Since that’s ground zero for the T‑cells, the drug gets right to the areas where it’s needed, stimulating the T‑cells to kill the virus.

DermaVir has shown promise in two human trials, Lisziewicz said.

Peter Kim, medical officer at the Division of Aids at NIAID, said he’s hopeful that much of the nano-based cancer research can help HIV researchers, since scientists in both fields face some of the same problems: toxic side effects, the need to target specific areas of the body and the difficulty of getting drugs to cross the blood-brain barrier.

“It doesn’t take a huge amount of imagination as to how it could cross the fence to the other side,” Kim said.

As with all areas of the fast-growing nanotechnology field, however, safety is a crucial area of concern in nanomedicine. In some ways, several researchers said, the biggest challenge is combating a growing public uneasiness with nanomaterials, which if left unchecked could prompt a backlash.

Andrew Owen, a lecturer at the University of Liverpool, said there’s ​“mitigated risk” with nanomedicine. He stressed that many scientists, including himself, are still working with cells, not whole animals or people, and that things that cause cell death in the lab may not translate to problems at a larger scale.

In many cases, he added, ​“we’re not talking about solid nanoparticles, we’re just talking about lumps of drug.” 

Still, Owen said, it’s clear that altering substances, such as drugs, to make them nano-sized does change their interaction with cells, so it’s vital to understand exactly what’s happening.

Mansoor Amiji, a professor at Northeastern University and the co-director of the school’s Nanomedicine Education & Research Consortium, said meetings like the one held last week are a good way to make sure scientists working in all areas of nanotechnology are aware of what the others are doing.

“The people who are developing very sophisticated nanoparticles and nanosystems and the people who are very much tuned into the biological problems — each one is kind of in their own little silo,” he said. ​“You don’t want to take something that will do more harm than good.”