The rise of bioplastics in medical devices

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In an era where sustainability is paramount, the most promising technological innovations are now targeting reduced use of plastics in medical devices. Worldwide, around 8 million tonnes of plastics are used in healthcare applications, and this figure is set to increase by around 8.6% between 2020 to 2027. Plastics play an essential role in the medical industry: single-use plastic devices such as syringes and catheters help with infection control, while the biocompatibility of plastics makes them suitable for direct contact with the human body, for example in MRI casings, prosthetics and intravenous tubing. Plastics also provide a more affordable, flexible alternative to traditional metal components in devices such as pacemakers and stents.

The success of conventional plastics and continued growth in their production and use are, however, causing major environmental issues. According to the British Plastics Federation (BPF) and the World Economic Forum, plastic production currently accounts for 8% of global oil consumption, and this is set to rise to 20% by 2050. Plastics have a huge carbon footprint due to reliance on fossil fuels throughout their lifecycle, from manufacturing to transport and disposal. By 2060, the Organisation for Economic Co-operation and Development (OECD) expects plastic-related emissions to exceed 4 billion tonnes of CO2 annually.

Waste management is increasingly problematic. In Europe alone, ‘25.8 million tonnes of post-consumer plastic waste is generated annually, of which 30% is recycled, with a further 40% destined for incineration’, stated Kevin O’Connor, Professor of Applied Microbiology and Biotechnology at University College Dublin, Ireland. At least 8 million tonnes of plastic go into the oceans each year, and according to experts from the French organisation Unitec, 12% of this waste is made up of microplastics, which infiltrate the food chain from plankton to humans, via fish and marine mammals.

Bioplastics, which are either biobased or made from biodegradable renewable materials, are now emerging as a true green technology. They are ‘considered superior polymers compared to synthetic plastics due to their biocompatibility and biodegradability, which make them exceptional for [biomedical] applications’, states Ajay K. Dalai, Professor of Chemical and Biological Engineering at the University of Saskatchewan, Saskatoon, Canada.

Various types of bioplastics are now being used to manufacture devices such as sutures, surgical instruments, implants and dressings. These materials are not only environmentally friendly but also have properties that can be tailored to specific needs.

Polylactic acid (PLA) is particularly dominant in medical devices, accounting for 40% of all biodegradable biopolymers. Rigid and very strong, it is increasingly used in single-use medical devices such as syringes and catheters due to its biocompatibility and biodegradability. 

Polyhydroxyalkanoates (PHA), which are produced by bacterial fermentation, are used in resorbable surgical implants. Poly-3-hydroxybutyrate (PHB) is ideal for osteosynthesis plates due to its controlled biodegradability. Polyglycolic acid (PGA), a natural polymer produced from fermented soybean seeds, is often used for resorbable surgical sutures. Polyamide 11 (PA 11) is derived from vegetable oils and ideal for surgical instruments and implants due to its high mechanical properties.

Regenerated cellulose is the most abundant natural biopolymer on Earth and is predominantly derived from renewable sources such as wood and cotton. Approximately 1.5 trillion tonnes are produced annually. It is notably used for dressings and dialysis membranes due to its biocompatibility. Polyhydroxyurethanes (PHU) also show promise for use in dressings and certain implants. 

Bioplastics have a promising future in medical technology. Advances in 3D printing mean that bioplastics can be used to create custom implants and surgical tools, while improvements in biopolymer processing and medical device design allow researchers to address issues such as polymeric stent recoil and clot-induced thrombosis.

French researchers from the Centre for Haemodynamics and Cardiology Intensive Care Unit in Lille have developed a solution combining chromium-platinum stents with PLA coating to elute anti-restenosis drugs. Another team from the Netherlands-based Aachen-Maastricht Institute for Biobased Materials have developed a polymer-based biodegradable stent prototype specifically for neurovascular surgery. Intelligent shape-memory bioplastics are also being studied for use in stents, and in aneurysm occlusion and clot removal devices. 

Bioplastics can also be used to create bio scaffolds that promote tissue regeneration and naturally degrade over time.  

“In tissue engineering applications, biopolymers have proven useful in replacing biogenic materials that could induce an immunogenic reaction due to a non-specific host response,” explains O’Connor. Five biopolymers are particularly effective in this area, safely degrading into non-toxic byproducts that are absorbed or excreted by the body. Poly(D,L-lactic acid) (PDLLA) degrades into lactic acid, which is naturally metabolised by the body, while poly(glycolide-co-lactide) (PGLA) is known for its predictable degradation rates.

Poly(butylene succinate) (PBS) is used in applications such as biodegradable packaging and agricultural films, and is being studied for medical uses such as tissue engineering scaffolds. Finally, poly-γ-glutamate (poly-γ-glutamic acid, γ-PGA) is water-soluble, biodegradable and non-toxic, making it suitable as a tissue engineering scaffold.

“A niche sector where PHA materials are preferred … for in vivo application by researchers is neurite guidance for peripheral nerve regeneration,” explains O’Connor. Many PHA materials have been investigated as heterologous nerve xenografts and in cardiac engineering applications, notably for endothelial cells from the carotid artery and jugular vein. 

While bioplastics remain a niche with only 1% of total plastic production, there is a movement towards their wider development, says O’Connor. According to European Bioplastics, in 2020, global production capacity exceeded 2.1 million tonnes, and is projected to reach 2.9 million tonnes by 2025, mainly driven by rising demand for biodegradable polymers in emerging economies. While starch blends dominate production, growth is mainly in PHA and PLA, for which production capacity has increased by a factor of 6 and 2 respectively, over the past five years.

Around 100 companies are active in this emerging market, across various applications. They include major chemical and petrochemical companies that are shifting part of their operations towards more sustainable solutions, along with specialist manufacturers. However, the industry remains cautious about the medical applications niche due to significant constraints. The transition to bioplastics in medicine involves more than simply replacing materials, since the stakes are so high. Experts at Polyvia (the French association of polymer processors) also note that as of 2024, bioplastics for medical devices are not being produced in sufficient volumes to achieve the economies of scale that would significantly bring down prices. While medical bioplastics currently offer a more sustainable alternative, they cost 20-40% more than petroleum-based plastics, regardless of the application. The raw materials are more expensive, and biotechnology-based production processes mean that production unit sizes require a rethink. The journey for bioplastics in medicine is just beginning.

Plastic surge: the expanding role of medical plastics in global healthcare 

The global medical plastics market is currently valued at US $22.26 billion, accounting for 2% of total plastics production by value, with an annual growth rate of 6.1%. The United States is responsible for approximately 40% of the consumption of global medical devices, followed by Europe and Japan. Growth in this sector is expected to be driven by increasing healthcare demand in developing countries such as Brazil, Russia, India and China, with the highest compound annual growth rate (6.9%) in the Asia-Pacific region.

The volume of plastics used in healthcare is substantial. In their study, Chantelle Rizan, Clinical Lecturer in Sustainable Healthcare at Brighton and Sussex Medical School, and colleagues ‘found that a single adenotonsillectomy operation in a UK hospital generated 101 separate pieces of single-use plastics.’ Studies from various countries estimate that plastics account for 30% of all healthcare waste, and about one-third of waste in intensive care and anaesthetics.

Since the US produces around 5.9 million tonnes of medical waste annually, this suggests that it creates around 1.7 million tonnes of plastic waste. ‘The UK National Health Service is estimated to dispose of 133,000 tonnes of plastic each year,’ added Rizan. The proportion of hospital waste made up of plastics varies between countries, from 12% in Peru to 27% in Jordan and 46% in Italy, likely reflecting different levels of single-use plastic consumption.

The environmental equation 

The use of bioplastics in medical devices enhances their environmental sustainability in several ways: 

1. Reducing dependence on non-renewable fossil resources. Bioplastics are derived from renewable resources such as plant biomass (corn, sugarcane, vegetable oils, etc.) rather than non-renewable fossil resources such as petroleum. This reduces the consumption of unsustainable raw materials in the manufacturing of medical devices. 
2. Shrinking the carbon footprint. The production of certain bioplastics, such as polyhydroxyalkanoates (PHA), is considered carbon-neutral, resulting in lower CO2 emissions compared to conventional petroleum-based plastics. This contributes to a reduction in the overall carbon footprint of medical device production.
3. Enhancing biodegradability. Unlike conventional plastics, bioplastics such as polylactic acid (PLA), PHA and regenerated cellulose are biodegradable. This helps tackle the problem of leftover plastic waste at the end of the lifecycle of disposable medical devices.

Bioplastics production by region 

Bioplastics production is unevenly distributed across the world. According to the industry association European Bioplastics, Asia remains the major production hub, with 46% of all bioplastics made in the region. This is followed by Europe, North America and South America, which account for 26%, 17% and 10% of global production respectively. Australia ranks last, with just 1% of the world’s bioplastics volumes. Asia is expected to see a significant increase in its share, potentially reaching 66% by 2027, largely at the expense of Europe.