Opinion: we need to realise that some plastics positively impact our lives by playing a vital role in the advancement of healthcare

By James Wilson and Anna Kargaard, Royal College of Surgeons In Ireland

We’ve all seen the recent news articles on plastics. Reduce/Reuse/Recycle in order to stop the plastic islands in the middle of the ocean destroying the marine wildlife. The landfills throughout the country where our rubbish is unloaded and buried to be forgotten about, but never to degrade or perish. An estimated eight million pieces of plastic dumped into the ocean each and every day.

So why then are we still in dire need of research into new plastics? Surely, this is a waste of funding when we should be using renewable and degradable alternatives?

While these news stories generally refer to packaging, we are still producing around 17.9 million tonnes of polyurethanes a year for upholstery, car parts and coatings, of which only a minute fraction is degradable. However, we can’t very well just stop this production while expecting everything to continue as it were before. So what can be done to tackle this conundrum?

From RTÉ Radio 1's Morning Ireland, a report on a new initiative which encourages trawlers to help reduce plastic waste in seas by bringing plastic back to ports

Paradoxically, the answer is to push for more research into polymers, of which plastics is the most well-known subcategory. New materials, sourced from renewable precursors and/or degradable in shorter time periods, are currently being scaled up from research to commercial products.

In 2017, 437 billion litres of bottled water was consumed generating a considerable amount of waste. Degradable alternatives, such as polylactic acid (PLA), are now starting to be introduced as an alternative packaging material for water bottles, which should reduce the burden of waste disposal. Similar to lactide, the precursor to PLA which is renewably sourced from sugarcane, other natural materials are constantly being investigated for the production of degradable plastics, including citrus fruits, flower oils, animal musks and recaptured carbon dioxide.

New packaging materials is not where all funding into materials science is currently going, with research also developing in the direction of implantable biomaterials. These are plastics that can be placed into the human body for medicinal or physiological benefit. Obviously, these are not the same plastics as used in packaging and are instead designed to be able to be implanted without any deleterious effect on the body. Some are degradable and some are not, though both are needed in order to alleviate certain ailments. After all, it would be incredibly unhelpful for a clot-preventing stent to degrade within the patient’s lifetime, but equally nonsensical to use non-degradable material in a suture.

From RTÉ Radio 1's Morning Ireland, Cathy Halloran reports on a University of Limerick project which converts plastic bottles into composites for new products including car and tractor parts

Without continued research into plastics, new breakthroughs into these materials would not have been made in the fields of implantable stents, bone repair, targeted drug release and more. For example, urethral catheters have been used since 3000 B.C. to relieve retention. At that time, they were rolled up palm leaves or the hollow tops of onions. In the 18th century, Benjamin Franklin developed the first flexible catheter from silver. Modern catheters have come a long way since Franklin’s time, with the use of malleable polymers such as polyurethanes, latex or rubber.

The rise of 3D-printing of polymers has led to the option of producing an object to fit almost any shape. It is used in the manufacture of sports equipment, car or aeroplane parts and medical devices, to name a few. In itself, on-demand 3D-printing has ramifications for reducing the amount of excess stock production for repair parts, which simultaneously extends the lifetime of some products through open availability.

3D-printing can be applied to biomaterials in the form of restructuring defects like broken bone or displaced cartilage, so that surgeries that were once either forced tissue removals or amputations can now be treated through implantation. This not only improves the patient's mobility, but also decreases the need for long-term aftercare or follow-up procedures, simultaneously boosting patient morale and decreasing socio-economic responsibility.

From RTÉ One's Six One News, a report on Belfast surgeons who carried out a kidney transplant using 3D technology

Yet another example of how polymers have had a part in the technical advancement of healthcare is in cardiovascular disease. Coronary stents took over from balloon angioplasty in the treatment of coronary artery disease, as balloon dilation caused arterial recoil or narrowing. The first stents were made of stainless steel, but they were not very flexible and caused stent-induced thrombosis.

With help from polymer research, these stents have evolved into the modern stents used in hospitals today, including drug-eluting stents and/or biodegradable vascular scaffolds. Polymeric stents have gone through many redesigns. Where the first generation of drug-eluting stents were found to cause an increased risk of heart attacks, the second generation of stents addressed these issues by using more biocompatible polymers. Stents made from fully biodegradable polymer coatings have been designed allowing the polymers to degrade simultaneously with a therapeutic drug. There has been a movement towards making fully biodegradable, polymeric stents.

Plenty of work clearly still needs to be done in the world of biomaterials research in order to benefit the healthcare system. However, mounting pressure against the use of plastic packaging, while not a bad thing, may cause a swing in opinion against research into plastics. Public opinion can have a large sway on the decisions made by the funding bodies on which projects to award funding. Instead of being outright against plastics, maybe consider which plastics you are against and push to improve those that positively impact our lives.

Dr James Wilson and Dr Anna Kargaard are postdoc researchers in the Department of Pharmaceutical & Medicinal Chemistry at the RCSI


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