Precious metals are increasingly likely to be in the medication prescribed by hospitals. Gold, silver and platinum have each been the subject of rigorous scientific study recently, and they crop up in the most surprising places.
Gold
Gold is present in everything from pacemakers and insulin pumps to pregnancy-testing kits and cancer treatments. “Gold has a long history of medical uses,” says Dr Richard Holliday, head of industrial applications at the World Gold Council. “In ancient China, doctors added gold flake to drinks for its reputed health benefits and it is still widely used in some aspects of Indian Ayurvedic medicine.”
In Western medicine, it first shot to prominence about 100 years ago.
Rheumatologists discovered that because of its anti-inflammatory properties, injections of pure gold (usually into thigh or buttock muscles) have some success in treating rheumatoid arthritis, an autoimmune disease in which joints become painful and inflamed.
A spokesperson for the Arthritis Research Campaign confirms that “intramuscular gold injections are sometimes used to treat patients because they can reduce swelling, stiffness and pain” but adds that possible side effects include problems with the blood, kidneys and skin, as well as nausea, so they are usually a last resort when other drugs have failed.
But, emerging research might change that. Trials at the University of Washington suggested that as many as 50% of people with rheumatoid arthritis — which affects 350 000 people in the UK — could benefit from gold injections.
A study currently under way in Denmark is investigating whether gold injections might also benefit people with osteoarthritis of the knee, a painful condition that occurs when joint surfaces become damaged, usually with wear and tear. It is thought that gold may slow down damage to the cartilage and bone, reducing joint pain.
Tiny gold seeds are also being used in the treatment of prostate cancer.
“Gold is opaque to x-rays,” says Holliday, so placing these seeds around the prostate helps doctors target their treatment more effectively. “This improved accuracy allows for a more precise radiation dose and a more targeted area for radiotherapy.”
An American company, called CytImmune Sciences, is currently carrying out human trials using gold to deliver chemotherapy drugs. “These very potent anti-cancer drugs are being attached to gold particles, which then preferentially locate to a tumour in the body,” Holliday says. “It is highly focused, so whereas normal chemotherapy would kill healthy cells as well as the diseased ones, this method targets just the cancerous cells.”
Scientists at the Massachusetts Institute of Technology are developing treatments for HIV that work in the same way.
Platinum
Since the 1970s, drugs containing platinum — the rarest and most precious metal — have been used to treat testicular and ovarian cancers. Now other forms of the disease have been added to the list. “Several types of frequently used chemotherapy drugs are derived from platinum,” says Dr Lesley Walker, Cancer Research UK’s director of cancer information. “Our scientists helped develop the platinum-based drugs carboplatin and cisplatin, two of the most successful anti-cancer treatments for lung, testicular, ovarian and head and neck cancer.” The platinum works by affecting the RNA and DNA of the cancer cells, ultimately destroying them.
Silver
Before 1940, silver was widely used as a powerful means of killing dangerous bacteria, but dropped out of favour with the discovery of antibiotics. Now, scientists are rediscovering its potent effects and colloidal silver — a liquid suspension of silver particles, sometimes called nanosilver — is being incorporated into everything from sticking plasters and burns dressings to treatments for stomach ulcers. It is also used as a preventative measure against eye infections in newborns.
Last year saw the first study looking at how silver could reduce bacteria levels in hospitals, carried out by the Heart of England hospital.
Researchers tested furniture and equipment made by the BioCote company, which incorporates silver in the manufacturing stage. Their results showed that wards containing the silver-based products — including blinds, bins, tiles, door handles and light switches – had 95,8% fewer bacteria in the environment than other wards. There were also 92,6% fewer surface bacteria on the silver-containing furniture.
A specialist panel of healthcare experts from various NHS trusts has been set up to investigate silver’s bug-busting powers further. “The Romans discovered that silver purifies water,” says Matthew Harte, a polymer chemist for BioCote. “Now it is being introduced to hundreds of UK hospitals including University College London hospital (UCLH), Birmingham hospital and the Royal orthopaedic hospital.”
Trevor Payne, facilities director at UCLH, says silver-based products could save lives. “Many hospitals are already using them so, when you open a door or use a hand dryer, it could well have reduced levels of bacteria and a lower risk of contamination,” he says.
Dr Tariq Khan, director of the Royal London homoeopathic hospital’s Marigold Clinic, helped to develop a product called Carnation Silversocks in conjunction with experts from Great Ormond Street children’s hospital.
Initially, the socks, made with silver-coated strands of cotton, were developed for patients with epidermolysis bullosa, a condition that causes the skin to blister at the slightest touch. Now on general sale, the socks have been shown to have other benefits, such as absorbing odour and, because silver has the highest thermal conductivity of any metal, will keep feet warm in winter and cool in summer.
Some water filters, such as those made by Brita, incorporate a special silver treatment to inhibit the growth of bacteria while a water cartridge is in use. Colloidal silver supplements can be bought from health shops, although a report by Harvard University last year warned there is no proof that taking silver by mouth has any benefits. In fact, common side effects include headaches, an upset stomach and skin turning a bluish grey as particles accumulate in the body.
“It is not an essential mineral,” says Louise Sutton, a dietician at Leeds Metropolitan University. “We have no need to consume it in the diet.” —