From easing creaky knees to mending a damaged heart, it seems that scientists are on the brink of using stem cells to revolutionise treating a range of conditions.
These master cells are essentially the building blocks of human tissue, and some have the capacity to turn into any type of specialist cell, such as skin, muscle or nerve.
Stem cells were hailed as a major medical breakthrough in the late Nineties when scientists discovered how to grow them in the lab.
But early progress was stymied, partly because these cells were originally harvested from embryos, leading to ethical concerns.
However, these worries eased with the discovery of so-called induced pluripotent stem cells about ten years ago. These are cells found in adults, which can be genetically reprogrammed to behave like embryonic stem cells, so they can become the cells of all organs and tissues. ‘We are on the cusp of major things,’ says Professor Brendon
Noble, adviser to the UK Stem Cell Foundation.
‘Stem cell therapies won’t just treat illnesses, they’ll cure them.’
Here we look at some of the treatments being tested in Britain that could soon be used on patients:
Heart attacks kill around 73,000 Britons a year.
Those who survive often suffer severe damage to the cardiac muscle that leaves them with heart failure, which causes breathlessness, swelling and fatigue. Until now there has been no way to repair this damage, but a trial at University College London is looking at whether injecting stem cells within hours of a heart attack can repair or replace the damaged cells.
The cells are harvested from a patient’s bone marrow, purified and then injected into the heart via a tube that is fed into the body through a leg artery.
Two or three days afterwards, the patient has an MRI scan of the heart to record the damage done by the heart attack.
A year later, they have another scan to see if the stem cells have helped healthy tissue grow and the results are compared with patients who did not get the stem cell injections.
The trial, involving 100 patients at University College London and Barts Health NHS Trust, ended in 2014 and the results should be available soon.
A similar study in the U.S. found that stem cell therapy halved deaths among patients who were so ill their only hope was a heart transplant.
Doctors at the Robert Jones and Agnes Hunt Orthopaedic Hospital, Shrewsbury, are testing 120 patients with osteoarthritis to see if injecting their own stem cells can repair damaged cartilage in the joints.
Osteoarthritis develops when cartilage, the body’s built-in shock absorber inside joints, breaks down.
The new trial involves extracting cells that make new cartilage (chondrocytes) from the knee to grow in the laboratory. These can then be implanted back into the damaged knees.
At the same time, bone marrow is taken from the patients’ hips to extract mesenchymal stem cells. These are capable of turning into bone, cartilage and tendon, which will then be implanted in the knee.
A third of the patients will get the chondrocytes, a third the mesenchymal stem cells and a third both.
Doctors think that combining the treatments will give the best results, potentially delaying or even avoiding the need for knee replacement surgery.
The first results should be available within two years.
More than half a million people in Britain have age-related macular degeneration (AMD) – damage to the macula, the area at the back of the eye that helps us pick out visual details.
Nine out of ten cases are dry AMD, where the macula is damaged by a build-up of debris. This condition comes on slowly.
In wet AMD, blood vessels grow underneath the macula, causing swelling and bleeding. This can result in blindness in as little as three months.
Treatment for wet AMD involves monthly injections of drugs that curb the growth of the abnormal blood vessels, but they can’t restore lost vision.
Last year, a trial began at Moorfields Eye Hospital using stem cell treatment to restore vision in patients with wet AMD. If it works, it will also be used to treat dry AMD.
Ten patients will have therapy using embryonic stem cells grown in the lab. These will be genetically activated – doctors will use proteins to ‘turn on’ the genes inside the cells that make them turn into retinal pigment epithelium (RPE) cells. These are the cells at the back of the eye that play a vital role in sustaining the health of photo-receptors, which allow us to see shade, contrast and colour.
If retinal cells die because of AMD, so do the photoreceptors, causing blindness.
‘If you replace RPE cells you get to keep the photoreceptor cells,’ says Professor Paul Whiting of the Drug Discovery Institute at University College London.
The trial will run until next year and could lead to a treatment within the next five years.
Around 85,000 people a year in the UK suffer an Achilles tendon injury – a tear in the tissue connecting the calf muscle to the heel bone.
It can take months to heal and the patient usually has to wear a plaster cast or boot throughout. Some need surgery.
However, a revolutionary trial at the Royal National Orthopaedic Hospital in Stanmore could lead to a better repair.
Ten patients will have mesenchymal stem cells taken from the bone marrow in the hip or sternum (chest bone). The cells are left to grow in the lab for four to five weeks, before being implanted directly into the damaged Achilles tendon.
Over six months, the tendons are measured using a 3D scan to see if healthy tissue has formed.
The therapy has been used in racehorses and the UK Stem Cell Foundation, which is funding the study, says it hopes it could lead to treatments for humans within three years
Multiple sclerosis (MS) causes the immune system to attack nerve fibres and their lining in the brain and spinal cord.
There are several UK trials looking at a stem cell cure for relapsing/remitting MS – the most common type.
At the Royal Hallamshire Hospital in Sheffield, doctors are trying to halt the disease by replacing the faulty immune system with a new one.
First, patients have millions of cells, called haematopoietic stem cells, extracted from their bone marrow and frozen.
These cells are at such an early stage of development they have not developed the flaws that trigger MS.
Then they undergo chemo-therapy to destroy the damaged immune system.
The fresh cells are thawed out and injected back into the blood, where it is hoped they will mature into the different types of white blood cells that make up the body’s immune system.
The full results have not yet been published, but some of the patients treated early in the trial had not suffered any relapses two years later.
INJURED VOICE BOX
The voice box, or larynx, is part of the windpipe and can be severely damaged by injury or cancer treatment.
Patients often have to breathe through a tube in the neck and speech may be impossible.
A trial which began last year at University College London, is using stem cells to grow a new larynx in the lab for ten patients.
They take a larynx from a donor and strip it of its DNA using detergents and enzymes.
Millions of stem cells are extracted from the patient’s bone marrow and ‘sprayed’ on to the stripped larynx, creating a new one for the patient.
Once these cells have attached and started to grow on the ‘scaffold’, it is implanted in the patient.
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