Tag Archives: nano-encapsulation

Nano and food discussion for beginners

I try to make sure there are a range of posts here for various levels of ‘nanotechnology sophistication’ but over time I’ve given less attention to ‘beginner’ posts, i.e., pieces where nanotechnology basics are explained as best as possible. This is largely due to concerns about repetition; I mean, how many times do you want to read that nano means one billionth?

In that spirit, this June 22, 2016 news item on Nanowerk about food and nanotechnology provides a good entry piece that is not terribly repetitive,

Every mouthful of food we eat is teeming with chemical reactions. Adding ingredients and cooking helps us control these reactions and makes the food taste better and last longer. So what if we could target food at the molecular level, sending in specially designed particles to control reactions even more tightly? Well, this is exactly what scientists are trying to do and it has already produced some impressive results – from food that tastes salty without the health risks of adding salt, to bread that contains healthy fish oil but without any fishy aftertaste.

But while this nanotechnology could significantly enhance our food, it also raises big questions about safety. We only have to look at the strong reaction against genetically modified foods to see how important this issue is. How can we ensure that nanotechnology in food will be different? Will our food be safe? And will people accept these new foods?

Nanotechnology is an emerging technology that creates and uses materials and particles at the scale of a nanometre, one billionth of a metre. To get an understanding of just how small this is, if you imagine a nanoparticle was the size of a football then an animal like a sheep would be as big as our planet.

Working with such small particles allows us to create materials and products with improved properties, from lighter bicycles and more durable beer bottles to cosmetic creams with better absorption and toothpastes that stop bacteria from growing. Being able to change a material’s properties means nanotechnology can help create many innovative food products and applications that change the way we process, preserve and package foods.

For example, nanotechnology can be used for “smart” packaging that can monitor the condition of foods while they are stored and transported. When foods are contaminated or going off, the sensors on the packaging pick up gases produced by bacteria and change colour to alert anyone who wants to eat the food.

A June 22, 2016 essay by Seda Erdem (University of Stirling; UK) on The Conversation, which originated the news item, provides more information in this excerpt,

Silver is already used in healthcare products such as dental equipment for its antibacterial properties. Nano-sizing silver particles improves their ability to kill bacteria because it increases the surface area of silver the bacteria are exposed to. Israeli scientists found that also coating packaging paper with nano-sized silver particles [also known as silver nanoparticles] combats bacteria such as E. coli and extends product shelf life.

Another example of nanotechnology’s use in food manufacturing is nano-encapsulation. This technology has been used to mask the taste and odour of tuna fish oil so that it could be used to enrich bread with heart healthy Omega-3 fatty acids. Fish oil particles are packed into a film coating that prevents the fish oil from reacting with oxygen and releasing its smell. The nanocapsules break open only when they reach the stomach so you can receive the health benefits of eating them without experiencing the odour.

Meanwhile, researchers at Nottingham University are looking into nanoscale salt particles than can increase the saltiness of food without increasing the amount of salt.

As with silver, breaking salt into smaller nanosize increases its surface area. This means its flavour can be spread more efficiently. The researchers claim this can reduce the salt content of standard crisps by 90% while keeping the same flavour.

Despite all the opportunities nanotechnology offers the food industry, most developments remain at the research and development stage. This slow uptake is due to the lack of information about the health and environmental impacts of the technology. For example, there is a concern whether ingested nanomaterials migrate to different parts of the body and accumulate in certain organs, such as liver and kidneys. This may then affect the functionality of these organs in the medium to long term.

Unknown risks

However, our knowledge of the risks associated with the use of nanomaterials is incomplete. These issues need to be better understood and addressed for the public to accept nanotechnology in food. This will also depend on the public’s understanding of the technology and how much they trust the food industry and the regulatory process watching over it.

Research has shown, for example, that consumers are more likely to accept nanotechnology when it is used in food packaging rather than in food processing. But nanotechnology in food production was seen as more acceptable if it increased the food’s health benefits, although consumers weren’t necessarily willing to pay more for this.

In our recent research, we found no strong attitudes towards or resistance to nanotechnology in food packaging in the UK. But there was still concern among a small group of consumers about the safety of foods. This shows how important it will be for food producers and regulators to provide consumers with the best available information about nanotechnology, including any uncertainties about the technology.

There you have it.

Overpromising and underdelivering: genome, stem cells, gene therapy and nano food

When people talk about overpromising (aka hype/hyperbole) and science, they’re usually referring to overexcited marketing collateral and/or a public relations initiative and/or news media coverage.  Scientists themselves don’t tend to be identified as one of the sources for hype even when that’s clearly the case. That’s right, scientists are people too and sometimes they get carried away by their enthusiasms as Emily Yoffe notes in her excellent Slate essay, The Medical Revolution; Where are the cures promised by stem cells, gene therapy, and the human genome? From Yoffe’s essay,

Dr. J. William Langston has been researching Parkinson’s disease for 25 years. At one time, it seemed likely he’d have to find another disease to study, because a cure for Parkinson’s looked imminent. In the late 1980s, the field of regenerative medicine seemed poised to make it possible for doctors to put healthy tissue in a damaged brain, reversing the destruction caused by the disease.

Langston was one of many optimists. In 1999, the then-head of the National Institute of Neurological Disorders and Stroke, Dr. Gerald Fischbach, testified before the Senate that with “skill and luck,” Parkinson’s could be cured in five to 10 years. Now Langston, who is 67, doesn’t think he’ll see a Parkinson’s cure in his professional lifetime. He no longer uses “the C word” and acknowledges he and others were naive. [emphasis mine] He understands the anger of patients who, he says, “are getting quite bitter” that they remain ill, long past the time when they thought they would have been restored to health.

The disappointments are so acute in part because the promises have been so big. Over the past two decades, we’ve been told that a new age of molecular medicine—using gene therapy, stem cells, and the knowledge gleaned from unlocking the human genome—would bring us medical miracles. [emphasis mine] Just as antibiotics conquered infectious diseases and vaccines eliminated the scourges of polio and smallpox, the ability to manipulate our cells and genes is supposed to vanquish everything from terrible inherited disorders, such as Huntington’s and cystic fibrosis, to widespread conditions like cancer, diabetes, and heart disease.

Yoffe goes on to outline the problems that researchers encounter when trying to ‘fix’ what’s gone wrong.

Parkinson’s disease was long held out as the model for new knowledge and technologies eradicating illnesses. Instead, it has become the model for its unforeseen consequences. [emphasis mine]

Langston, head of the Parkinson’s Institute and Clinical Center, explains that scientists believed the damage to patients took place in a discrete part of the brain, the substantia nigra. “It was a small target. All we’d have to do was replace the missing cells, do it once, and that would cure the disease,” Langston says. “We were wrong about that. This disease hits many other areas of the brain. You can’t just put transplants here and there. The brain is not a pincushion.”

Disease of all kinds have proven to be infinitely more complex than first realized. Disease is not ’cause and effect’ driven so much as it is a process with an infinite number of potential inputs and any number of potential outcomes. Take for example gene therapy (Note: the human genome project was supposed to yield gene therapies),

In some ways, gene therapy for boys with a deadly immune disorder, X-linked severe combined immune deficiency, also known as “bubble boy” disease, is the miracle made manifest. Inserting good genes into these children has allowed some to live normal lives. Unfortunately, within a few years of treatment, a significant minority have developed leukemia. The gene therapy, it turns out, activated existing cancer-causing genes in these children. This results in what the co-discoverer of the structure of DNA, James Watson, calls “the depressing calculus” of curing an invariably fatal disease—and hoping it doesn’t cause a sometimes-fatal one.

For me, it seems that that the human genome project was akin to taking a clock apart. Looking at the constituent parts and replacing broken ones does not guarantee that you will be able assemble a more efficient working version unless you know how the clock worked in the first place. We still don’t understand the basic parts, the genes,  interact with each other, within their environment, or with external inputs.

The state of our ignorance is illustrated by the recent sequencing of the genome of Bishop Desmond Tutu and four Bushmen. Three of the Bushmen had a gene mutation associated with a liver disease that kills people while young. But the Bushmen are all over 80—which means either the variation doesn’t actually cause the disease, or there are other factors protecting the Bushmen.

As for the pressures acting on the scientists themselves,

There are forces, both external and internal, on scientists that almost require them to oversell. Without money, there’s no science. Researchers must constantly convince administrators who control tax dollars, investors, and individual donors that the work they are doing will make a difference. Nancy Wexler says that in order to get funding, “You have to promise cures, that you’ll meet certain milestones within a certain time frame.”

The infomercial-level hype for both gene therapy and stem cells is not just because scientists are trying to convince funders, but because they want to believe. [emphases mine]

Scientific advances as one of Yoffe’s interview subjects points out involve a process dogged with failure and setbacks requiring an attitude of humility laced with patience and practiced over decades before an ‘overnight success’ occurs, if it ever does.

I was reminded of Yoffe’s article after reading a nano food article recently written by Kate Kelland for Reuters,

In a taste of things to come, food scientists say they have cooked up a way of using nanotechnology to make low-fat or fat-free foods just as appetizing and satisfying as their full-fat fellows.

The implications could be significant in combating the spread of health problems such as obesity, diabetes and heart disease.

There are two promising areas of research. First, they are looking at ways to slow digestion,

One thing they might look into is work by scientists at Britain’s Institute of Food Research (IFR), who said last month they had found an unexpected synergy that helped break down fat and might lead to new ways of slowing digestion, and ultimately to creating foods that made consumers feel fuller.

“Much of the fat in processed foods is eaten in the form of emulsions such as soups, yoghurt, ice cream and mayonnaise,” said the IFR’s Peter Wilde. “We are unpicking the mechanisms of digestion used to break them down so we can design fats in a rational way that are digested more slowly.”

The idea is that if digestion is slower, the final section of the intestine called the ileum will be put on its “ileal brake,” sending a signal to the consumer that means they feel full even though they have eaten less fat

This sounds harmless and it’s even possible it’s a good idea but then replacing diseased tissue with healthy tissue, as they tried with Parkinson’s Disease gene therapies, seemed like a good idea too. Just how well is the digestive process understood?

As for the second promising area of research,

Experts see promise in another nano technique which involves encapsulating nutrients in bubble-like structures known as vesicles that can be engineered to break down and release their contents at specific stages in the digestive system.

According to Vic Morris, a nano expert at the IFR, this technique in a larger form, micro-encapsulation, was well established in the food industry. The major difference with nano-encapsulation was that the smaller size might be able to take nutrients further or deliver them to more appropriate places. [emphasis mine]

They’ve been talking about trying to encapsulate and target medicines to more appropriate places and, as far as I’m aware, to no avail. I sense a little overenthusiasm on the experts’ part. Kelland does try to counterbalance this by discussing other issues with nanofood such as secretiveness about the food companies’ research, experts’ concerns over nanoparticles, and public concerns over genetically modified food. Still the allure of ‘all you can eat with no consequences’ is likely to overshadow any journalist’s attempt at balanced reporting with resulting disappointment when somebody realizes it’s all much more complicated than we thought.

Dexter Johnson’s Sept. 22, 2010 posting ( Protein-based Nanotubes Pass Electrical Signals Between Cells) on his Nanoclast blog offers more proof that we still have a lot to learn about basic biological processes,

A few years back, scientists led by Hans-Hermann Gerdes at the University of Bergen noticed that there were nanoscale tubes connecting cells sometimes over significant distances. This discovery launched a field known somewhat by the term in the biological community as the “nanotube field.”

Microbiologists remained somewhat skeptical on what this phenomenon was and weren’t entirely pleased with some explanations offered because they seemed to fall outside “existing biological concepts.”

So let’s start summing up.  The team notices nanotubes that connect cells over distances which microbiologists have difficulty accepting as “they [seem] to fall outside existing biological concepts. [emphasis mine] Now the team has published a paper which suggests that electrical signals pass through the nanotubes and that a ‘gap junction’ enables transmission to nonadjacent cells.  (Dexter’s description provides  more technical detail in an accessible writing style.)

As Dexter notes,

Another key biological question it helps address–or complicate, as the case may be–is the complexity of the human brain. This research makes the brain drastically more complex than originally thought, according to Gerdes. [emphasis mine]

Getting back to where I started, scientists are people too. They have their enthusiasms as well as pressure to get grants and produce results for governments and other investors, not to mention their own egos.  And while I’ve focused on the biological and medical sciences in this article, I think that all the sciences yield more questions than answers and that everything is far more complicated and  interconnected than we have yet to realize.