Will dental visits soon be easier?

By Catherine

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

Calling in Sick

By Catherine

Written by Catherine Bolgar

One day, your phone might detect that you have cancer and alert your doctor. It’s among the new diagnostics being developed to spot health problems faster.

Cancer cells, bacteria and certain non-infectious diseases give off volatile organic compounds which the blood eventually transports to our lungs to be expelled into the atmosphere, explains Hossam Haick, professor at Haifa’s Israel Institute of Technology. He is part of a team developing a handheld device with gold nanoparticle sensors that can detect volatile organic compounds in breath samples.

Each disease has a unique breath print, he says. The team’s sensors can detect 23 diseases, including cancers of the lung, breast, ovaries, head and neck, lung, stomach, kidney and prostate, as well as pulmonary hypertension, tuberculosis, and even Parkinson’s disease and Alzheimer’s disease.

Cancer “exists in humans for five to 15 years before we start to see its effects,” Dr. Haick says.

If we want to detect cancer early, we have to do it when people feel good. That’s why we want to detect it by exhaling. It’s painless, so people will be willing to do it.”

Dr. Haick started with lung cancer in 2007. “If you detect lung cancer early, the survival rate is 70%,” he says. “If the cancer is at advanced stages, the survival rate is 9%-15%.”

Today, X-rays and computerized tomography scans detect tumors, but only a biopsy (i.e surgery) can determine if they are malignant—and 96% are not, Dr. Haick says. The sensors can distinguish between benign and malignant cancer, thus reducing the need for biopsies.
Dr. Haick hopes to produce a handheld device for around $800, affordable for clinical doctors. He’s also working with a European consortium to integrate the device into smart phones. “When we speak on the phone we exhale a lot of breath, and we can use that to monitor disease,” Dr. Haick says. The phone would alert the owner’s doctor, who would decide how to manage the results.

Similarly, a team at the Mayo Clinic in Rochester, Minn., is working on a noninvasive screening for several cancers simultaneously, by detecting DNA markers in a blood or stool sample.

While cancer lurks for years, infections can become serious in hours. On TV dramas, doctors examine samples under microscopes and find the solution in minutes. In reality, samples are sent to a lab where they are cultured—which can involve growing bacteria or viruses for six to 24 hours—or undergo polymerase chain reaction (PCR), a complex process that takes about six hours.

Emergency room patients with an infection can’t wait that long, so doctors immediately administer a range of antibiotics. But overuse of antibiotics has led to resistance, and in any case the drugs don’t work on viruses.

Jeong-Yeol Yoon, professor of agricultural and biosystems engineering and biomedical engineering at the University of Arizona in Tucson, has found “a whole new way of doing PCR” utilizing interfacial effects, that’s cheaper, easier and much faster—the whole process takes less than 10 minutes.

Normally, PCR identifies the pathogen by looking at the DNA in the sample. The DNA is first extracted and purified, which can take three or four hours. The amount of DNA is tiny, so it’s amplified by an enzyme and heated and cooled repeatedly. Each cycle doubles the DNA, so “if you repeat the cycle 30 times you’ll have about a million copies, theoretically,” Dr. Yoon explains.

Dr. Yoon’s team instead uses an approach called droplet-on-thermocouple silhouette real-time polymerase chain reaction (DOTS qPCR). The method can identify infection after just three to eight cycles. And the process uses water droplets, which separate contaminants, eliminating the time-consuming step of purifying the sample. The entire process, from sample to answer, can take just five to 10 minutes.

Regular PCR requires expensive equipment and trained lab personnel. But Dr. Yoon hopes to make a fully automated DOTS qPCR device for under $1,000, so it can be used in poorer countries where diseases such as Ebola, MERS, SARS and bird flu require speedy quarantines to prevent epidemics.

Genetics play a key part in other new early diagnostics methods. For example, Stanford University researchers have identified a pattern of gene activity that could lead to a quick blood test for sepsis, which kills 750,000 people annually in the U.S. alone. Meanwhile, a University of Utah team has found DNA anomalies that predict how an ovarian-cancer patient will respond to platinum-based chemotherapy. And scientists at the University of Toronto are using next-generation sequencing to match a sample against a database of thousands of bacteria and viruses, eliminating the need to test one by one.


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

The Secrets of Protein

By Catherine

Written by Catherine Bolgar

If genes are our bodies’ architectural plans, then proteins are the internal devices that make decisions, send signals and ensure that our metabolism operates properly. The study of proteins in our cells and tissue is known as proteomics, a term coined in 1994 by Marc Wilkins, now professor of systems biology at the University of New South Wales in Sydney.

Proteomics began with a lofty goal: to “figure out what all the proteins are inside cells,” Dr. Wilkins recalls. Two years ago “we could say we had found all the proteins one would expect to find inside a bacteria cell or yeast cell.” Last year, two research groups declared that they had found 85%-90% of the proteins inside the human cell. Another expects to publish a list of all human proteins later this year—a milestone as important as sequencing the human genome.

Proteins are responsible for the basic aspects of metabolism: they convert food into amino acids, sugar or other states that the body can use. Proteins are also the functional molecules inside systems. Like antennae, they sense what’s happening outside the cell, and transmit signals inside the body.

Some proteins are decision makers,” Dr. Wilkins explains. “There are not that many of them in a cell. But there are lots of copies of ‘worker’ proteins. It’s like corporate organization, with executives and workers.”

Scientists have long understood what ‘worker’ proteins do, but for years, “it was hard to get good data on proteins that pass information to each other (known as signal transduction) and transcription factors that decide what proteins are made inside the cell, which have a big influence on what cells are doing. They’re important for the specialization that happens in all cells; regulating a kidney cell is very different from a brain cell,” Dr. Wilkins says.

iStock_000014137699_SmallSignal transduction proteins are the “middle-men” that connect cell receptors on the outside of cells to proteins in the cell nucleus. They sense and integrate information, and decide which proteins need to be made, Dr. Wilkins explains. For example, human growth hormone, or erythropoietin, produced by the kidney, is a protein that tells bone marrow to make more red blood cells.

Recent advances in mass spectrometry, coupled with faster computers, now allow scientists to analyze all the rare proteins inside the cell.

There are 20,000 proteins inside the human body,” Dr. Wilkins points out. “We have good information on what 11,000 to 12,000 of the proteins do. But for a third to half of the human proteins, we have very little idea of what the function is.”

A better understanding of these lesser-known proteins would aid research into many health issues. In particular, proteomics could tell us which signaling and decision-making proteins are associated with cancer, and help in its early detection, by discovering protein biomarkers. We know, for example, that some breast cancer cells make too much HER2 protein, which can then be targeted by biopharmaceutical drugs that include monoclonal antibodies (themselves proteins).

But the process is far from straightforward. “The challenge with biopharmaceuticals is you don’t synthesize them chemically,” Dr. Wilkins says; they’re made by other cells such as bacteria, yeast or mammalian cells. “When you use cells to make proteins… the cell is also making all its usual other proteins. So when you go to purify the drug, the protein of interest is there but with thousands of others,” he says. “Also, you have to make sure all the decorations on the protein are accurate for it to be effective …[or] it can set off a patient’s immune system and have disastrous results.” Proteomics and better instrumentation can resolve these quality-control issues.

Proteomics’ potential extends far beyond a cure for cancer. It’s “a general technology platform, so it can be applied to the analysis of every living thing in biological sciences,” Dr. Wilkins says. Viruses, bacteria, yeasts in bread, wine or beer, enzymes in laundry soap, animal and human food supplements, and more, all involve proteins.

“We are just now starting to identify all the proteins in cells,” Dr. Wilkins says, “and so must now tackle the next challenge: to understand how these interact with each other to form all the hundreds of molecular machines inside the cell, and how these function in the normal cell and change in disease.”


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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