The tiny scale of medical breakthroughs

By Catherine
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Written by Catherine Bolgar

 

Nanomedicine takes advantage of its extremely small size—“nano” being one-millionth of a millimeter—to target drugs inside the body, fight cancer and other diseases, regenerate cells and provide contrast for medical imaging. As a result, nanomedicines hold out hope of curing hard-to-treat diseases. However, it also triggers fears, not least about whether they are safe for patients and the environment, and whether they are sufficiently regulated.

To date, about 40 nanomedicines have been approved by the U.S. Food and Drug Administration and about 20 by the European Medicines Agency, says Patrick Boisseau, nanomedicine program manager at the French Atomic Energy Commission and chairman of European Technology Platform on Nanomedicine. A further 130 nanomedicines are in clinical trials. It can take more than a decade for a drug, including nanomedicines, to receive regulatory approval.

However, despite this progress, much public discussion relating to nanomedicine is in fact based on their confusion with engineered nanomaterials, mostly inorganic materials produced by industry in large quantities.

“Most of the reactions expressed by citizens are directed at these [engineered] materials because products aren’t labeled and people don’t know whether appropriate toxicological studies have been performed as to whether the nanomaterials are safe for humans or the environment,” Mr. Boisseau says.

The only link between nanomaterials and nanomedicines,” he adds, “is the need to develop specific analytical techniques because the nanoscale is very, very small.”

Materials may behave differently at nanoscale, which is why nanotechnology is potentially so powerful, but also why ensuring safety, especially of nanomedicines, is so difficult, says Michael Schillmeier, professor of sociology, philosophy and anthropology at the University of Exeter in the U.K. and nanomedicine specialist.

“We can’t say nanomedicine is safe or not safe because nanoparticles can be very different, depending which nanoparticles are involved and how they interact with their environment,” he says. “Just by being nanoscale, they can be more toxic, more reactive, more resistant to erosion. There is no one nanoparticle.”

While materials may act differently on the nano scale compared with the macro scale, there can also be variations within a single substance. Nanomedicines’ impact can differ depending on their size, shape and texture. The trick is to understand whether such differences are positive or negative.

“We went to laboratories and toxicologists and found they often lack technologies or know how to sufficiently test and characterize nanoparticles,” says Prof. Schillmeier.

However, if clinicians discover specific properties of nanomedicines compared with macro forms of those drugs, they are required to inform regulators, Mr. Boisseau says.

“The body is a fantastic machine,” he adds. “Particles below five nanometers are filtered by the kidneys and quickly eliminated in urine, depending on whether the nanomaterial is organic or inorganic. Already, regulation for all medicines requires you to explain how your medicine is eliminated.”

The fact that the body doesn’t degrade inorganic particles can be useful in medicine. Metallic nanoparticles, for example, are injected into advanced cancerous tumors to enhance radiotherapy and destroy more cancer cells without increasing the radiation dose, he notes.

“If the patient is already 60 years old and, without treatment, could expect to live six months, and with it six years, then the regulator says the benefit is higher than the risk,” Mr. Boisseau says. “It would be different for treating young children because we do not know if children can live for 60 or 70 years with metallic nanoparticles in the body.”

Some medicines use nano properties to deliver drugs more efficiently to where they’re needed in the body. Often the drugs are strong, such as chemotherapy for cancer, but better-targeted delivery can make drugs work better while lessening side effects. Eventually, nanomedicine might make personalized medicine possible.

For now, research is focusing on drugs coated with nanotechnology that better target cancer and other diseases and distinguish between cancer cells and healthy cells, Prof. Schillmeier says.

Nanomedicine is not revolutionizing medicine, but may improve it.”

Meanwhile, pharmaceutical companies are looking at developing new nanomedicines or innovative nano-delivery systems for old drugs, Mr. Boisseau says. “Most people don’t care whether they have nanomedicine or not,” he notes. “They just care about therapeutic solutions that will treat them with the fewest side effects and best outcome.”

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion on LinkedIn.

Photos courtesy of iStock

Controlling the genetic genie

By Catherine
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Written by Catherine Bolgar

Advances in genetic sequencing techniques and discoveries about our DNA are helping to identify inherited diseases, and someday may lead to treatments or personalized medicine. But can regulation keep up with the science, securing the health benefits, while protecting those whose test results bring bad news?

Genetic tests promise great insights. They may diagnose disease or find the mutated gene responsible. They can detect whether a genetic disorder could be passed on to children, and which disorders in newborns might need early treatment. And tests can identify biological relationships, as well as victims of crime or catastrophe.

There are about 4,000 to 5,000 diseases that can be tracked back to a mutation in a known gene,” says Alastair Kent, director of Genetic Alliance U.K., in London. “There are probably more but the gene hasn’t yet been identified. They are rare, and most are incredibly rare.”

About 80% of inherited diseases become apparent soon after birth or in early childhood, he says, and most are fatal by age five. There are about 400 rare genetic conditions for which treatments can improve and prolong life, and some recent therapies may cure some people, Mr. Kent says, but “it’s too soon to tell.”

The most prevalent diseases caused by a single gene are Down syndrome, blood-related disorders such as thalassemia, sickle-cell anemia and hemophilia, followed by cystic fibrosis, Tay-Sachs disease, Fragile X syndrome and Huntington’s disease.

Cystic fibrosis treatments have improved life spans, but Huntington’s, a degenerative brain disorder, has no cure—and anyone with the genetic mutation is certain to get the disease. Understandably, people want to test for a late-onset genetic disease usually because a family member already has it. Knowing whether they too are carriers could influence important life decisions, such as whether to have children or retire.

However, you can’t just say, “do my genome,” Mr. Kent notes.

Having a defective gene, such as APOE-e4 for Alzheimer’s, or BRCA1 for breast cancer, doesn’t always lead to the disease. Women with BRCA1, for example, sometimes choose to have a mastectomy to reduce the risk.

Given the difficulties associated with such decisions, most countries try to protect genetic privacy. The European Union requires patient consent for disclosure of genetic information and bans discrimination based on genetic features. In the U.K., insurers have agreed not to ask for predictive genetic test results except for policies above £500,000 ($757,000). In the U.S., the Genetic Information Non-Discrimination Act prohibits discrimination by employers or insurers on genetic grounds.

Companies that conduct genetic tests directly for consumers also guard client privacy. 23andMe, a personal genetics company (named after our 23 pairs of chromosomes) based in Mountain View, Calif., has more than a million genotyped customers. Their data is stripped of personal identifiers such as name, address or email, and aggregated with other data, according to Emily Drabant Conley, vice president of business development.

Though the volume of genetic data is expanding, testing can accomplish only so much. “We don’t have the knowledge to interpret the information that comes out of sequencing except in a relatively small proportion of cases,” Mr. Kent notes.

While some genetic mutations will always result in the related disease, in many cases, it’s not possible to give an exact risk of developing a disorder or to predict its severity. Genetic alterations are not always informative—after all, we all have DNA variations.

“Certain conditions and diseases are genetically determined. There are a number of Mendelian diseases that are almost completely determined by your genes—for example, conditions like Tay-Sachs, cystic fibrosis, and sickle cell anemia. In other cases, genetic factors may increase or decrease a person’s risk for a particular condition, but environmental and lifestyle factors also play a role,” Ms. Drabant Conley says.

In 2009, an Italian court reduced the prison sentence of a convicted murderer after discovering that he carried genetic variants associated with a predisposition to aggressiveness.

“But if you look at people who carry that mutation, some have a fairly aggressive personality but others are successful entrepreneurs,” says Mr. Kent. “You have to be extremely careful in associating complex behavioral characteristics with underlying genetic structures.”

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion on LinkedIn.

Photos courtesy of iStock

Will dental visits soon be easier?

By Catherine
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Written by Catherine Bolgar

New devices and materials promise to make dentist visits more pleasant, and help maintain our teeth between checkups. Here’s how.

Devices: Dentists may soon be able to eliminate tooth cavities quickly and painlessly without any drilling or filling. Tooth-destroying plaque, which feeds on dissolved food, comprises a complex mixture of bacteria that release acids into teeth, slowly dissolving dental minerals. But researchers at Reminova Ltd., a King’s College London corporate spinoff, have developed a device that re-inserts the calcium and phosphate minerals.

“We can stop the process and we can reverse it,” says Christopher Longbottom, fellow at King’s College London and Reminova co-founder. It’s not straightforward, but he says, we “can speed up the process of remineralization.”

Two or three agents clean out the proteins and lipids that have seeped through the plaque and replaced the minerals, then a tiny, imperceptible current drives the good minerals back into the tooth. The process takes about one hour, which Reminova hopes to reduce to between 20 and 30 minutes.

An alternative method is for a graphene sensor 50 microns thick (i.e., half the width of a human hair) with gold electrodes acting as an antenna, to be printed onto water-soluble silk and “tattooed” onto the tooth. As Manu Sebastian Mannoor, assistant professor at the Stevens Institute of Technology in Hoboken, N.J., explains, the graphene, which conducts the bacteria’s electrical charge, is coated with peptides that bind to bacteria such as streptococcus mutans, listeria or salmonella.

A dentist could read the sensor like a radio frequency identification (RFID) tag to ascertain the extent of any decay or disease. The latter might include Heliobacter pylori, which is associated with stomach ulcers and cancer when found in saliva. Sensors could also be attached to bacteria-hosting objects such as hospital door handles or intravenous bags, warning of exposure to the likes of staphlylococcus.

Materials: For over 150 years, dentists have filled tooth cavities with mercury-based silver amalgam. More recently, researchers have sought alternatives, encouraged not least by the 2013 United Nations Minamata Convention on Mercury, which aims to reduce its harmful health and environmental effects.

One such possibility, for use as fillings and crowns, is glass ionomer cements. These enjoy numerous advantages: they don’t need an intermediary adhesive to bond to the tooth; like a tooth they expand and contract as temperatures change; they’re biocompatible; and they release fluoride. However, “the strength of these materials has not yet reached an optimal level,” says Ana Raquel Benetti, dentist and researcher at the Department of Odontology at the University of Copenhagen.

Dr. Benetti and Dr. Heloisa Bordallo studied the structure of conventional glass ionomer cements, with the aim of improving their durability. “Our work shows liquid mobility within the cements,” Dr. Benetti explains.

By improving the binding of the liquid to the cement structure, the material might become stronger.”

In other advances, scientists at the University of Rochester and University of Pennsylvania have found a way to use nanoparticles to deliver the antibacterial agent farnesol to plaque. Meanwhile, researchers at Anhui Medical University in Hefei, China, and the University of Hong Kong drew inspiration from the way mussels attach themselves to surfaces, and used a similar polydopamine to coat teeth, which helps remineralize their dentin, or interior.

And scientists at the Ninth People’s Hospital, Shanghai Key Laboratory, Shanghai Research Institute of Stomatology and Shanghai Jiao Ton University in China found that graphene oxide can fight bacteria in the mouth. Unlike treatments for tooth and gum-disease that rely on antibiotics (despite increasingly drug-resistant bacteria), graphene oxide destroys the bacteria’s cell walls and membranes, inhibiting their growth. One day, we might all protect our teeth with nanosheets.

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

Photos courtesy of iStock



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