Cathleen Hess, Sabic, talks high performance plastics
Cathleen Hess, Sabic’s Innovative Plastics business looks at protecting staff and patients with high performance plastics
According to the World Health Organisation (WHO), healthcare-associated infections (HCAIs) can result in prolonged hospital stays, create long-term disabilities, increase resistance to antimicrobials and generate high costs for patients and their families. To help combat this issue, the healthcare industry continues to prioritise efforts to help reduce the number of patients contracting infections while in the hospital or while administering healthcare in the home.
The WHO estimates that approximately 30% of patients in intensive care units (ICUs) in high-income countries are affected by at least one healthcare-associated infection. In low and middle income countries, the frequency of ICU-acquired infections is at least two to three times higher and associated infection densities related to devices are up to 13 times higher, than in the USA. Newborns in developing countries are at an even higher risk of acquiring an HCAI with infection rates 3-20 times higher than in high-income countries.
High-touch medical devices, including electronic equipment encased in plastics, which are inadequately decontaminated can lead to the indirect transmission of pathogens. Regardless of region, there is no doubt that there is an urgent need for new solutions to be identified to help minimize the spread of HCAIs.
Sabic’s Innovative Plastics business continues to develop materials with properties that can contribute to protecting both staff and patients from infection. Working closely with customers to understand their challenges has led to several key solutions, including materials with enhanced sterilisation performance, materials with antimicrobial properties and materials that meet a wide range of chemical resistance requirements which can withstand more aggressive cleaning.
The intensifying focus on the range of processes used to sterilise medical and dental equipment and devices continues to grow. Trends in the industry are pointing towards designing more inherent functional capabilities into reusable devices, meaning that they are more likely to contain sensitive electronics (vulnerable to heat and moisture) or other features which could require different sterilisation options. Materials must now be able to withstand a number of different sterilisation processes which have the potential to degrade devices over time, diminishing their mechanical integrity, interfering with performance, or altering their aesthetics. Resin material technologies such as Sabic’s ULTEM HU1004 resin have evolved to help answer this need for enhanced protection and can be a significant factor prolonging the life of expensive medical and dental equipment by enabling it to better withstand intensive sterilization processes.
Medical devices can be subjected to a variety of sterilisation processes, including gamma radiation, hydrogen peroxide gas sterilisation (a low temperature sterilization process) and high temperature steam autoclave (up to 134°C). ULTEM HU1004 resin, a thermoplastic polyetherimide (PEI) material, has proven capabilities in each sterilization environment. Sabic has worked closely with Indusbello, a medical device manufacturer in Brazil, to develop a differentiated solution using ULTEM HU1004 resin for sterilization trays to help improve the safety of patients and clinician healthcare environments. Pre-assessed for biocompatibility per ISO 10993, this material can also provide flexibility in design, transparency, superior aesthetics and enhanced productivity through injection molding.
For opaque applications such as sterilisation tray bottoms where mechanical and physical property retention may be higher in priority than colour aesthetics, NORYL HNA055 resin offers impact resistance, dimensional stability, chemical resistance, hydrolytic stability and strong property retention after steam sterilisation at both 120°C and up to 134°C.
The repeated wipe down of medical equipment with increasingly aggressive disinfectants to prevent the spread of HCAIs is putting devices at risk for substantial wear and tear known as environmental stress cracking (ESC). ESC in medical devices as well as structural applications such as hospital bed components, can be related to many factors including polymer morphology, chemical concentration and residual stress in moulded components. Sabic’s range of engineered thermoplastics has been developed to help medical device manufacturers meet challenging chemical resistance requirements. Enhanced chemical resistance performance test data which includes results from an ESC resistance study, shows the performance of Sabic’s materials when repeatedly exposed to aggressive disinfectants. The study looks at compatibility of common flame resistant medical enclosure materials tested with alcohol / quaternary ammonium compound (QAC)-based disinfectants and alcohol-free / QAC-based disinfectants, which are commonly used disinfectants to help prevent the spread of infections.
Designing healthcare applications with materials that can reduce the potential transfer of pathogens is another approach to help control the spread of infection. Sabic has developed a range of LNP antimicrobial thermoplastics compounds created with silver-based antimicrobial additives. The use of silver is key to the efficacy of these compounds, as silver is adaptable for diverse applications and is accepted as a broad-spectrum antimicrobial, with activity against multiple pathogens, including gram-positive and gram-negative bacteria, mould and fungus.
The antimicrobial portfolio comprises nine different grades across four product lines. Two levels of antimicrobial efficacy allow manufacturers to choose the solution that works best for their applications. When following ISO testing protocols under laboratory conditions (specifically the ISO test for MRSA), five of the ‘high effect’ antimicrobial LNP grades (used for high-touch applications) have a log reduction value greater than 4, representing a 99.99% reduction of pathogens. Four of the ‘low effect’ antimicrobial LNP grades (used for low-touch applications) have a log reduction value of less than 4, representing a 99.0-99.99% reduction of pathogens. These compounds have the potential to be used in a variety of medical device applications, such as monitoring and imaging devices and other device housings, as well as surgical instruments, fluid and drug delivery products, and structural applications such as operating tables.
In addition to the importance of minimising the spread of infection in hospitals, the move towards greater outpatient care and home administration of medication has created the need for improved safety in the home healthcare environment. Drug delivery device manufacturers are looking for solutions that can make it easy and safe for patients to accurately administer their own medication. Sabic is helping the industry adapt to this trend with its new CYCOLOY HCX1640 resin, which meets standard healthcare regulations and can enable the design of robust, light and attractive drug delivery devices, such as insulin pens. Our material technologies help manufacturers achieve thin walls and dimensional stability, as well as improved weld line performance and impact resistance. These features enable the creation of complex designs that are capable of integrating an increased number of mechanical or electronic features.
As the need for improved safety in hospital and home settings continues to rise, material innovators can play a significant role in developing new technologies to help create a clean and non-threatening environment for patients and clinicians alike.