Analysis: The importance, value and use of platinum today is quite astonishing given that the metal was considered a nuisance when first discovered

By Paul O'Dowd, RCSI

When we think of platinum, we usually think about wedding rings, jewellery or even "platinum cards" offered by banks, businesses and airlines. Platinum is seen as a sleek and shiny competitor to the premium niche gold has held for many years. But the metal's utility goes far beyond what we see on the high street. Platinum is a versatile metal that plays important roles in many industries, from tackling climate change, to saving lives.

It first arrived on earth over four billion years ago, when meteorites collided with the planet and delivered the Earth’s entire supply of the metal. The first recorded use of the metal dates back to ancient times with traces of platinum found in hieroglyphics in Egyptian burial chambers. Later, tribes in South America used the metal to make nose rings and other pieces of jewellery.

From Thoisoi2 - Chemical Experiments, why platinum is the most precious metal on earth

In the 16th century Spanish conquistadors found platinum when mining for gold and silver, but they considered it a nuisance metal and termed it "platina", meaning little silver, and threw it away. The official discovery of the metal is credited to Spaniard Antonio de Ulloa in 1735 following his scientific description of the metal after seeing Native Americans mining. Since then, the uses of platinum have expanded greatly with platinum becoming an important material in many different industries.

When it comes to the car industry and vehicle emissions, platinum has played a central role in reducing pollutants for over 40 years, through its use in catalytic converters. In these systems, platinum along with other metals such as palladium and rhodium increase the speed of reactions, to convert toxic exhaust emissions into less toxic gasses. Platinum assists this process by increasing the rate of conversion of carbon monoxide into carbon dioxide, which is less damaging to the environment. Overall, catalytic converters reduce harmful emissions from cars by up to 90%, which is impressive given that only a tiny amount of metal (around five grams) is present.

From RTÉ Radio 1's Liveline, why are thieves targeting catalytic converters in cars?

After the automotive industry, the second biggest use of platinum is in the jewellery industry. This is not surprising given platinum belongs to a group known as noble metals, meaning that it is resistant to corrosion and unreactive to water in air. Indeed, platinum is the least reactive metal along with being an easy metal to mould into different shapes. The greyish-white dense metal is also much rarer than gold, so much so that all the platinum ever mined would not fill an Olympic-sized swimming pool! These properties make platinum jewellery highly desirable, with many watch companies releasing limited edition platinum watches, and platinum wedding rings being a popular choice.

While many readers may be aware of some of these uses of platinum, it is probably less well known for its application in biomedical science. As platinum is highly durable and conductive, it allows electricity to flow through it. In its metallic state, platinum is also biocompatible, meaning it is non-toxic and stable within the body, which makes it an ideal material for devices such as catheters, stents and pacemakers.

Platinum is also radiopaque meaning it doesn't allow x-rays to pass through it, which allows the location of platinum containing materials to be monitored within the body. This allows for devices to be observed during surgery and platinum tipped wires to be used to guide devices to desired locations in some procedures.

The greyish-white metal is much rarer than gold, so much so that all the platinum ever mined would not fill an Olympic-sized swimming pool!

Platinum also plays a central role in chemotherapeutics for treating cancer. Overall, platinum chemotherapeutics are used in nearly 50% of all treatments to combat cancer, a disease that overtook cardiovascular disease as the leading cause of death in rich countries last year. When metals are chemically combined with other elements, materials known as complexes are formed. These complexes behave differently than unreacted metals and can be used to tackle a wide range of diseases.

The first platinum anti-cancer complex, cisplatin, was approved in 1978, and there are three platinum drugs clinically approved today worldwide for treating cancer with a further three approved in specific countries. Despite their widespread use, these drugs have multiple side effects and, during treatments, cancer cells often become resistant to the drugs. These are the two main issues that have faced the use of platinum drugs since their inception over 40 years ago, although much research today is focussed on overcoming these problems.

Ireland is a hub of cutting-edge research when it comes to tackling the issues associated with platinum chemotherapeutics. One example of this is current research by the Griffith Group in the Royal College of Surgeons Ireland. Our research strives to develop a better understanding of how platinum cancer drugs interact with cells inside the body, and to develop strategies to selectively target cancer cells instead of healthy cells. We achieve these goals by linking platinum drugs to either targeting agents or tracking agents.

The use of platinum to reduce emissions and in chemotherapeutics is only scratching the surface of a diverse history of the metal in many industries

Collaborations with universities across Ireland and international institutes such as Oxford University is helping make this work possible and shines a light on the importance of scientists working together across the globe. The hope is that this research will help fuel a new and improved generation of platinum chemotherapeutics.

The importance of platinum today and its potential for the future is quite astonishing given it was first considered a nuisance. What's even more impressive is that the use of platinum to reduce emissions and in chemotherapeutics is only scratching the surface of a diverse history of the metal in many industries. The next time you use a platinum card or see platinum jewellery, remember there’s so much more to the metal than first meets the eye.

Paul O'Dowd is a PhD researcher with SSPC, the SFI Research Centre for Pharmaceuticals, and the Department of Chemistry in the RCSI.

The views expressed here are those of the author and do not represent or reflect the views of RTÉ