Platinum anti-cancer drugs
Platinum has the ability, in certain chemical forms, to inhibit the division of living cells. The discovery of this property in 1962 led to the development of platinum-based drugs to treat a wide range of cancers. Cisplatin, the first platinum anti-cancer drug, began to be used in treatment in 1977. Testicular cancer was found to be susceptible to treatment with cisplatin and there were other successes with ovarian, head and neck cancers.
Researchers at the Institute of Cancer Research and the Royal Marsden Hospital in London achieved a significant step when they found a compound similar to cisplatin in terms of activity, but much less toxic. This drug, carboplatin, was first approved in 1986. Recent research has sought to identify new platinum compounds which will treat tumours which do not respond to or which become resistant to cisplatin and carboplatin. The first of these drugs to reach commercialization is oxaliplatin, which is being marketed under the trade name Eloxatin.
Upcoming platinum anti-cancer drugs include satraplatin, which is being developed for treatment of prostate cancer. It is claimed that the use of satraplatin results in a higher survival rate than with existing chemotherapy treatments. Satraplatin will also be the first platinum anti-cancer drug that can be administered orally instead of intravenously, allowing patients to be treated at home. The drug is currently undergoing clinical trials.
Platinum biomedical components
Platinum can be fabricated into very tiny, complex components. As it is inert, platinum does not corrode inside the body, while allergic reactions to platinum are extremely rare. Platinum also has good electrical conductivity, which makes it an ideal electrode material.
Pacemakers, used to treat heart disorders which result in slow or irregular heartbeat, usually contain at least two platinum-iridium electrodes, through which pulses of electricity are transmitted to stabilise the heartbeat. Platinum electrodes are also found in pacemaker-like devices which are used to help people at risk of fatal disturbances in the heart's rhythm. This risk can be minimised by implanting a device known as an Internal Cardioverter Defibrillator (ICD) which sends a massive electric charge to the heart as soon as it detects a problem.
Catheters, flexible tubes which can be introduced into the arteries, are widely used in modern, minimally-invasive treatments for heart disease. Many catheters contain platinum marker bands and guide wires, which are used to help the surgeon guide the device to the treatment site. The radio-opacity of platinum, which makes it visible in x-ray images, enables doctors to monitor the position of the catheter during treatment.