Advances in sterilisation technology: safeguarding global health 

Sterilisation is critical in healthcare systems and over the years the need for more effective and environmentally friendly methods has resulted in significant advancements. We provide an overview of current sterilisation technologies and outline potential future trends. By Sally Turner.

Credit: Shutterstock/Evgeniy Kalinovskiy

Sterilisation and disinfection have always been central to modern healthcare and the Covid-19 pandemic highlighted the importance of infection control in both a public and personal capacity. These crucial processes have come a long way since 19th century pioneers Louis Pasteur, Joseph Lister and William Henry laid the foundation for modern techniques.  

Sterilisation is the process of destroying all forms of microbial life (including bacteria, viruses and fungi) on surfaces or in fluids and is carried out in healthcare settings by physical or chemical methods. Disinfection eliminates many or all pathogenic microorganisms, except bacterial spores, on inanimate objects. 

In 2022, an innovative review of this sector found that sterilisation and disinfection used in tandem are most effective in protecting public health, and that both advanced and conventional methods are useful in global healthcare. 

Advances in conventional methods  

Autoclaving (steam sterilisation) has undergone vast improvements in efficiency thanks to advances in pressure settings, temperature control and cycle duration. The use of high-pressure steam has led to faster sterilisation cycles, and the integration of real-time monitoring systems and automated controls has reduced errors and increased reliability. 

Ethylene oxide revolutionised the sterilisation of heat- and moisture-sensitive medical devices. However, its environmental impact and concerns over safety led to the development of alternative methods. Innovations in peracetic acid sterilisation systems and hydrogen peroxide and have resulted in safer and more environmentally friendly alternatives with fewer toxic byproducts and shorter cycle times. 

Radiation includes the use of X-rays, gamma rays and electron beams and provides an alternative sterilisation method to heat or chemical exposure. It has become a more accessible option in healthcare since undergoing improvements in safety and dose control. 

Filtration-based sterilisation uses microfiltration, ultrafiltration, and nanofiltration techniques to remove microorganisms where heat or chemical sterilisation may adversely affect the product's quality. (It is more commonly used in the food and beverage industry to extend shelf life). 

Emerging trends 

Pulsed light (PL), gas plasma, and joint techniques (vacuum ultraviolet) are vastly improving efficiency in sterilisation as they are able to target difficult-to-reach areas; they are also more versatile when sterilising a broad range of materials. 

Pulsed light technology (PL) utilises intense pulses of light to kill microorganisms and has some advantages over other sterilisation techniques – it does not leave any kind of residue and is rapid in comparison with heat or chemical processes. 

Gas plasma uses electric and magnetic fields to create a plasma that can sterilise surfaces. Low-temperature ionised gases such as nitrogen, oxygen, helium, argon and xenon are utilised as a source of plasma sterilisation which is a useful option for fragile medical devices. Ozone sterilisation, using ozone gas, has become popular as an environmentally friendly and highly effective method for disinfection. 

Joint techniques combine vacuum ultraviolet (VUV) radiation with other agents such as hydrogen peroxide or ozone to optimise sterilisation. VUV radiation is safe to use with heat-sensitive materials and eliminates a wide range of microorganisms.  

Automation has optimised the traceability of sterilisation processes, ensuring greater compliance with regulatory legislation. It has also improved efficiency by reducing human errors; robotics systems operate with precision and consistency which means sterilisation outcomes can be more easily standardised. This makes them eminently safer and more reliable. 

Nanotechnology is also set to transform sterilisation as minute nanomaterials with antimicrobial properties can be integrated into medical devices and other products. This process inhibits microbial growth ongoing; it improves the sterilisation process and also establishes s a self-sustaining microbial barrier. 

Using nanomaterials to deliver drugs to treat TB and infectious lung diseases can provide numerous advantages over traditional drug delivery methods.

While NPs have been developed for TB over the past decade, the therapeutic systems have become prominent using diagnostic and therapeutic methods (theranostic). Theranostic approaches to TB management were designed to conduct nuclear imaging, optical imaging, ultrasound, imaging with magnetic resonance, and computed tomography. 

Problems with resistance to conventional TB drugs mean therapeutic methods require high doses of numerous medications over a longer time. Issues with the practical capabilities of traditional drugs for TB also exist. Solubility, stability, and penetration impact the drugs’ effectiveness. Traditional drugs may also create resistance over time, a relapse, and extend to other body parts, leading to secondary TB.  

Challenges in sterilisation processes 

According to the Centers for Disease Control and Prevention (CDC), factors that impact upon efficacy of both disinfection and sterilisation include “prior cleaning of the object; organic and inorganic load present; type and level of microbial contamination; concentration of and exposure time to the germicide; physical nature of the object (e.g., crevices, hinges, and lumens); presence of biofilms; temperature and pH of the disinfection process; and in some cases, relative humidity of the sterilization process (e.g., ethylene oxide).” 

Environmental concerns and issues with toxicity have also been at the forefront of emerging technologies. Innovations have increasingly focused on ‘green’ methods such as electron beam irradiation and ozone sterilisation as these use less energy and produce fewer harmful byproducts which makes them more environmentally sustainable. 

Future Outlook 

Rapid sterilisation is becoming essential in healthcare systems which are facing financial pressures, time constraints and staff shortages. Advanced sterilisation techniques tend to provide faster cycle times, reducing the overall processing time compared to conventional methods such as heat or filtration.  

Pulsed light technology, gas plasma, and joint techniques offer efficient, ‘green’ alternatives to conventional methods such as heat, irradiation, filtration and liquid and gaseous sterilisation. Each process has its pros and cons, but together these techniques provide a toolbox of sterilisation options, enabling healthcare providers to choose the most appropriate method based on their specific needs, material compatibility, and desired outcomes.  

The sterilisation services market is projected to grow from $117m to reach $12.7bn by 2030, according to a recent report. Awareness about the importance of sterilisation and infection control has remained high since the Covid-19 pandemic and the report suggests this “will drive a sustained demand for sterilisation services across industries”. In addition, “stringent regulations and guidelines by regulatory authorities to maintain safety standards will further bolster the market growth”.  

Ongoing research and development in sterilisation technology will also ensure that innovations in processes lead to more effective, efficient, and environmentally sustainable solutions.