Your body’s superpowers

The remarkable abilities already inside us.

Norovirus might have laid you low for a short while, but you’re recovering, aren’t you? Your immune system is to die for. Researchers are still getting to grips with how it works but at every turn it has thrown out marvellous surprises. In the early days of vaccination against tuberculosis, for example, it was noted that it protected you not only from TB, but a host of other diseases, too.

We still don’t know why; it’s clear that we have yet to understand the full power of the human immune system. Just in December, for instance, we learned that the system’s T-cells, which fight viruses and bacteria, are not all created equal. Almost all of our knowledge of human T-cells has come from blood samples. But research using T-cells harvested from the organs of New York cadavers has shown that each region of the body has its own particular way of fighting invaders. Columbia University’s Donna Farber, who led the study, believes this discovery may open up the path to tightly focused vaccines that can activate the most appropriate of the body’s immune responses.

Her optimism is supported by another surprise the immune system has just delivered. New Scientist reported this month that there is now hope for a vaccine against age-related macular degeneration (AMD), an incurable condition that blinds millions of people around the world.

AMD comes from the build-up of proteins and other debris on the retina. In healthy people this is cleared away by specialist cells. Those cells stop working in people with AMD. This appears to have two consequences: the build-up of debris continues and the light-sensitive cells of the retina beneath the debris start to die off. The result is a slowly widening black hole at the centre of your field of vision.

Pioneering treatments with a laser can stimulate the nonfunctioning cells to get them going again, which is exactly what Robyn Guymer of the University of Melbourne was trying to do in his trial on 50 patients. The idea was to try the laser treatment in one eye and leave the other eye as a control. Then tests on each eye would show what improvements the procedure could give.

So, you could imagine it was a little frustrating that in the tests the lasered eye didn’t seem to be that much better than the one that had been left alone. But Guymer soon realised this was because the vision of the untreated eye had also improved. The laser surgery had stimulated the patients’ immune system to respond to alarm calls from the eye.

Your eyes are usually offlimits to your immune system. It seems a sensible evolutionary trick, because the immune system’s standard response causes inflammation, which could be catastrophic in an instrument as sensitive as the eye. However, the cells destroyed by the laser appear to send out a signal so loud that the immune system overrides the safety mechanism and sends in the troops – to both eyes – to restore order.

There is now hope that AMD can be treated with a routine procedure at a very early stage, and that those most at risk of developing it can have their immune systems stimulated before the symptoms appear. But there is a wider lesson: with various successes in vaccines against cancer – particularly colon cancer – looking likely in the next few years, it’s becoming clear that the most profitable path for medicine might be to explore partnerships with the remarkable abilities that already lie within us.

Michael Brooks’s “The Secret Anarchy of Science” is published by Profile Books (£8.99)

There is now hope for a vaccine against age-related macular degeneration. Photograph: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 28 January 2013 issue of the New Statesman, After Chavez

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Apple-cervix ears and spinach-vein hearts: Will humans soon be “biohacked”?

Leafy greens could save your life – and not just if you eat them.

You are what you eat, and now bioengineers are repurposing culinary staples as “ghost bodies” – scaffolding on which human tissues can be grown. Nicknamed “biohacking”, this manipulation of vegetation has potentially meaty consequences for both regenerative medicine and cosmetic body modification.

A recent study, published in Biomaterials journal, details the innovative use of spinach leaves as vascular scaffolds. The branching network of plant vasculature is similar to our human system for transporting blood, and now this resemblance has been put to likely life-saving use. Prior to this, there have been no ways of reproducing the smallest veins in the human body, which are less than 10 micrometres in diameter.

The team of researchers responsible for desecrating Popeye’s favourite food is led by bioengineering professor Glenn Gaudette and PhD student Joshua Gershlak at the Worcester Polytechnic Institute (WPI). They were discussing the dearth of organ donors over lunch when they were inspired to use their lunch to help solve the problem.

In 2015 the NHS released figures showing that in the last decade over 6000 people, including 270 children, had died while waiting for an organ transplant. Hearts, in particular, are in short supply as it is so far impossible to perfectly recreate a human heart. After a heart attack, often there is a portion of tissue that no longer beats, and so cannot push blood around the body. A major obstacle to resolving this is the inability to engineer dense heart muscle, peppered with enough capillaries. There must be adequate flow of oxygenated blood to every cell in order to avoid tissue death.

However, the scientists had an ingenious thought – each thin, flat spinach leaf already came equipped with its own microscopic system of channels. If these leaves were stacked together, the resulting hunk of human muscle would be dense and veiny. Cautiously, the team lined the cellulose matrix with cardiac muscle cells and monitored their progress. After five days they were amazed to note that the cells had begun to contract – like a beating heart. Microbeads, roughly the same size as blood cells, were pumped through the veins successfully.

Although the leafy engineering was a success, scientists are currently unaware of how to proceed with grafting their artificial channels into a real vasculatory system, not least because of the potential for rejection. Additionally, there is the worry that the detergents used to strip the rigid protein matrix from the rest of the leaf (in order for human endothelial cells to be seeded onto this “cellulose scaffolding”) may ruin the viability of the cells. Luckily, cellulose is known to be “biocompatible”, meaning your body is unlikely to reject it if it is properly buried under your skin.

Elsa Sotiriadis, Programme Director at RebelBio & SOSventures, told me: “cellulose is a promising, widely abundant scaffolding material, as it is renewable, inexpensive and biodegradable”, adding that “once major hurdles - like heat-induced decomposition and undesirable consistency at high concentrations - are overcome, it could rapidly transform 3D-bioprinting”. 

This is only the most recent instance of “bio-hacking”, the attempt to fuse plant and human biology. Last year scientists at the Pelling Laboratory for Biophysical Manipulation at the University of Ottawa used the same “scrubbing” process to separate the cellulose from a slice of Macintosh red apple and repopulate it with “HeLa” cervix cells. The human ear made from a garden variety piece of fruit and some cervix was intended as a powerful artistic statement, playing on the 1997 story of the human ear successfully grafted onto the back of a live mouse. In contrast to the WPI researchers, whose focus is on advancing regenerative medicine – the idea that artificial body parts may replace malfunctioning organic ones – Andrew Pelling, head of the Pelling Laboratory, is more interested in possible cosmetic applications and the idea of biohacking as simply an extension of existing methods of modification such as tattooing.

Speaking to WIRED, Pelling said: “If you need an implant - an ear, a nose - why should that aesthetic be dictated by the company that's created it? Why shouldn't you control the appearance, by doing it yourself or commissioning someone to make an organ?

The public health agency in Canada, which is unusually open to Pelling’s “augmented biology”, has supported his company selling modified body parts. Most significantly, the resources needed for this kind of biohacking – primarily physical, rather than pharmacological or genetic – are abundant and cheap. There are countless different forms of plant life to bend to our body ideals – parsley, wormwood, and peanut hairy roots have already been trialled, and the WPI team are already considering the similarities between broccoli and human lungs. As Pelling demonstrated by obtaining his equipment via dumpster-diving and then open-sourcing the instructions on how to assemble everything correctly, the hardware and recipes are also freely available.

Biohacking is gaining popularity among bioengineers, especially because of the possibility for even wackier uses. In his interview with WIRED, Pelling was excited about the possibility of using plants to make us sexier, wondering whether we could “build an erogenous interaction using materials that have textures you find pleasing [to change how our skin feels]? We're looking at asparagus, fennel, mushroom...” If he has his way, one day soon the saying “you are what you eat” could have an entirely different meaning.

Anjuli R. K. Shere is a 2016/17 Wellcome Scholar and science intern at the New Statesman

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