Age No Bar

Regenerated heart valves, vein-repair patches, spare skin and replacement joints will soon allow for 50 active years after 50. T.V. Jayan reports
…..Age No Bar
That anti-wrinkle cream may look tempting — but scientists say there’s more to ageing than creased skin and greying hair. These are just the telltale signs of age. What gets eroded inside the body is the real problem.

If some scientists have their way, it won’t be a problem for long. They are trying to battle an ageing heart, hip and knees that give in to the wear and tear of passing years and blood veins that cannot keep up with the demands of round-the-clock blood circulation, leading to dead cells.

John Fisher, a professor of mechanical engineering at the University of Leeds, the UK, is determined to look into these problems and find solutions so that people can lead an active life beyond the age of 50. While people are living longer than ever before, the effort is to help them discard the baggage of old age.

The West is facing a crisis — of an increasing older population. There are nearly 35 pensioners for every 100 workers in European countries. The pensioners are expected to surge to 75 for every 100 workers by 2050. According to a recent study in Lancet, half the babies now born in wealthy nations are expected to live to the age of 100 years, further aggravating the problem.

The Institute of Medical and Biological Engineering (iMBE), which Fisher heads at the university, will spend £50 million (Rs 375 crore) over the next year to tackle 10 challenges that will allow people “50 active years after 50”.

The project, launched in partnership with academic institutions and private industry from a number of countries, intends to develop long-lasting, better performing biomedical implants and regeneration techniques.

On the list are regenerated heart valves, vein-repair patches, new ligaments and cartilage, spare skin and replacement joints that can be bought off the shelf.

While medical advances, a better diet and changes in our lifestyle mean we are living longer, our bones, joints and cardiovascular systems continue to degenerate as we age, says Fisher.

Current technologies are good, but they are not adequate to last 50 years. For instance, the best of artificial hip joints can’t last more than 15-20 years at a stretch, “particularly if you want to cycle, play tennis, or ski,” says Fisher. “There is a crying need to improve the quality and durability of prostheses available for use currently,” adds Sanjeev Jain, a consulting orthopaedic surgeon and joint replacement expert at the Dr L.H. Hiranandani Hospital in Mumbai.

A typical replacement hip joint has a metal head in a polyethylene cup, which wears out over time. Because of its limited lifespan, many patients are advised to wait for as long as possible, often in considerable discomfort, before having an artificial hip put in place.

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There is another design which is used in younger patients. Since a relatively younger person who needs a hip replacement may take 100 million steps for the rest of his or her lifetime, the artificial hip joint has to last longer. The replacement hips now available for younger patients are either made of metal or ceramics. Both are more durable than polyethylene, giving the joint a longer lifespan and reducing the need for a further surgery.

A few years ago, the Leeds university team further modified the design to create a better model. Both ceramics and metal are used in the new hip joint. The bearing includes a new type of ceramic ball, which fits inside a metal cup. The combination has led to a 10-fold reduction in metal wear than in the metal joint. The joints, in clinical trials for the last five years, were found to be 10 times more durable than the other designs. Over 10,000 people are living with these new-generation hip replacements.

Similarly, as we get older, soft tissues begin to wear out — affecting organs such as the heart. A person with damaged tissues can go for an artificial implant, a chemically treated animal tissue or use a human donor tissue. An artificial implant or animal tissue will not lead to new tissues. The human donor tissue contains foreign cells which may eventually lead to the decay of the tissue.

On the other hand, the iMBE scientists have already developed a novel technique for re-creating human tissues. Developed and patented in 2001, it employs a unique method of stripping cells from human and animal tissues to leave a “scaffold” into which the patient’s own cells can be introduced.

“We have already used this to make a range of soft tissues,” says Eileen Ingham, professor of medical immunology at Leeds. These include heart valves, membranes that can be used for surgical and vascular repair, ligaments, cartilage found in knee joints and tissues such as skin and bladder, she says.

Take the heart valve. There are, as of now, three options available to patients who require a heart valve replacement. They can go for a mechanical valve, but it will require a life-long anti-coagulation therapy, which will significantly affect their quality of life. They can also opt for an artificial valve created from an animal tissue that can be used after a chemical treatment, or they can opt for a human donor valve. These will deteriorate over time and won’t last for more than 15 years.

But when the scientists tried out their “a-cellular” scaffold on sheep, they found that it gave birth to live cells within six months. Human trials have been taking place in Brazil for the last four years and the technology is expected to be available for human use in a few years.

A technology marvel that would be of enormous use is being attempted by the scientists in dental and bone care. The scientists have identified a peptide, a polymer produced when various amino acids found in the body come together, that can fight the decay of teeth, which are constantly attacked by acids. Exposure to acids leads to cavities. The scientists have found that the peptide, when applied in a liquid form by brush or as a mouthwash, can help create tiny three-dimensional structures that can fight tooth decay. Calcium, which is available through food, is naturally attracted by the peptide, creating a natural repair to the tooth. The scientists are hoping to extend the same technique for regeneration and repair of other soft and skeletal tissues such as blood vessels, bones and cartilage.

Fisher hopes that they may be able to develop at least 10 products over the next five years and halve the time required to get these products to market.

The new interventions will eventually be of immense value to India, which is also witnessing an increase in life expectancy. “Currently, 43 per cent of the global population of 80-plus people live in four countries including India,” says K.R. Gangadharan, founder of Heritage Hospital in Hyderabad and vice-president, International Federation on Ageing, a Canada-based non-profit organisation. Once the developments reach India, the aged may have the reason — and the joint — to do a jig.

Source: The Telegraph (Kolkata, India)

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