Michael Barbella, Managing Editor12.13.22
Bye bye, bacteria.
Scientists have developed a promising new weapon in the war against hospital-acquired infections. UCLA specialists are fine-tuning an anti-microbial barrier they created for implantable medical devices using zwitterionic material and ultraviolet light. Zwitterionic substances are comprised of molecules that possess an equal amount of cationic and anionic groups, thereby rendering them electrically neutral.
The UCLA team built the barrier by depositing a thin layer of zwitterionic material to a device surface and then bonding it to the underlying substrate through UV light irradiation. Early clin- ical results are encouraging—laboratory testing shows the surface treatment reduces biofilm growth by more than 80% and in some cases up to 93%, depending on the bacterial strain.
“The modified surfaces exhibited robust resistance against microorganisms and proteins, which is precisely what we sought to achieve,” Richard Kaner, a UCLA Dr. Myung Ki Hong professor of Materials Innovation, and senior research author, told the university’s news service earlier this year. “The surfaces greatly reduced or even prevented biofilm formation. Our early clinical results have been outstanding.”
Those results are based on 16 long-term urinary catheter users who switched to silicone devices containing the zwitterionic surface treatment. The modified catheter is the first product made by SILQ Technologies Corp., a UCLA spinout company Kaner founded out of his lab in April 2020. The catheter has been cleared for use by the U.S. Food and Drug Administration.
Materials science is key to medtech innovation. New and improved manufacturing materials have led to advancements such as bioprinting, skin-friendly adhesives, shape memory plastics, bioactive glass (orthopedic repair), and bioresorbable stents.
MPO’s materials feature examines the latest trends and challenges in medtech materials science, as well as the factors driving innovation in this field. Gaurav Lalwani, global medical applications engineering lead at Carpenter Technology, was among the experts interviewed for this story; his full input is provided in the following Q&A:
Michael Barbella: What are the latest trends in medical device materials? What factors are driving these trends?
Gaurav Lalwani: Medical devices are an active area of high impact innovation and there are several trends that have made a positive impact on improving patient outcomes. The two most important trends are additive manufacturing (3D printing) and robotic/minimally invasive surgeries. Additive manufacturing provides accessibility to novel implant designs that can provide design features not possible using traditional manufacturing, such as creation of porous implants for enhanced osteointegration and patient-specific implants along with production of complex device designs that are either not possible or too expensive to produce using subtractive manufacturing. Robotic and minimally invasive surgeries are focused on reducing post operational recovery times by enabling precision laparoscopic surgical procedures via a small incision. Improving patient outcomes is the focus of all innovation in medical devices and availability of raw materials to enable support and development is critical.
Barbella: What factors are driving innovation in medical device materials science?
Lalwani: Innovation in medical device materials is directly driven by the need to support and enable the latest device designs and trends. Robotic and minimally invasive surgeries need smaller devices and tools, which drive the need for high strength and tighter tolerance raw material feedstock. Additionally, to improve productivity and eliminate machining scrap, efforts are underway to reduce the residual stress in stainless steel products. Carpenter Technology currently supplies a portfolio of high strength tight tolerance premium stainless, cobalt and titanium alloys—for example, the enhanced machining Project 70+ stainless steel—and is also investigating production of novel low-residual stress 17-4 stainless steel products. Regulatory changes can also drive innovation in medical materials. For instance, the up classification of cobalt and changes in EUMDR led Carpenter to further optimize its melt protocols and scrap streams to enable production of commonly used stainless steel alloys with Cobalt below 0.10 wt% to be EU MDR compliant.
Barbella: What material challenges are associated with medical device miniaturization and how can these challenges be overcome?
Lalwani: Miniaturization of devices for robotic and minimally invasive surgeries require high strength alloys with tight tolerance and advanced machining operations that rely on minimal run-out to ensure consistency, minimal user involvement, tight tolerances, and repeatability from part to part. Carpenter is currently developing a minimum residual stress 17-4PH bar stock for some unique medical machining applications to ensure consistency from bar-to-bar. Ultimately, this would ensure minimal deflection during the machining operation and open the door to advanced, hands-off manufacturing of complex and thin-wall geometries. As trends towards minimally invasive surgeries continue, the need for smaller devices will require both the precision of advanced machining and the characteristics of next-generation materials, where more performance is packed into a smaller unit volume. A great example of this is Carpenter’s BioDur 108 alloy, which takes the performance expectations of an industry standard (vacuum melted 316 stainless) and increases strength, corrosion resistance, fatigue, and biocompatibility (Ni and Co removal for regulatory and allergic concerns).
Barbella: How have materials suppliers managed the supply chain challenges prompted by the pandemic, and what lessons (changes) might they implement going forward to avoid future problems/issues?
Lalwani: While COVID-19 has certainly caused significant challenges to supply chain management of raw materials, positive changes to the engagement between OEMs, contract manufacturers and material suppliers have been extensive. As one of the larger producers of both metal implant and instrument materials in the medical device space, we have significantly increased our strategic involvement, partnerships, and communication within this space, resulting in a much better understanding of the overall needs of the market. This has resulted in new and differentiated programs at Carpenter, such as strategic staging of Work-in-Process (WIP) materials to help stabilize lead-times during uncertain demand times, stocking opportunities at our regional warehouses to aid with just-in-time (JIT) delivery requests, and more contractual agreements with directed buy programs. The initiatives help OEMs manage and shore up supply continuity regardless of their strategy to manufacture in-house, outsource machining, or some combination of both. The pandemic has certainly caused underlying challenges to rise to the surface and overall, at least in the metals space, has helped initiate positive changes. Building on that momentum, we believe that working together and increasing transparency between OEMs, CMs, and material suppliers will help us all navigate the current demand uncertainly better and hope for continued progression in the years to come.
Barbella: In what ways has the COVID-19 pandemic spurred medical materials innovation, if at all?
Lalwani: There has been an interest in developing antimicrobial materials over the last several years. Materials systems containing additional elements such as silver and copper introduced in the base alloy chemistry or as an external coating have been extensively investigated. Due to COVID-19, these initiatives have a renewed focus and remain an active area of research with OEMs and contract manufacturers introducing new devices with improved antimicrobial surfaces.
Barbella: How can materials help improve and/or achieve medical device sustainability?
Lalwani: Materials play a critical role in improving medical device sustainability. For instance, 3D printed medical devices with porous architectures that allow for better osteointegration have been reported to improve initial fracture stabilization and minimize aseptic loosening of implants. High strength corrosion resistant alloys with enhanced fatigue performance improves implant life and reduces the risk of revision surgeries. Alloys that exhibit enhanced EM shielding are used in cardiovascular applications for pacemakers cans and are proven to enhance performance and longevity.
Barbella: Please discuss an instance (example) of an innovative material solution your company came up with to meet a challenging customer request.
Lalwani: Under new EU Medical Devices Regulation (EU MDR, 2017/745), medical devices that contain more than 0.10 wt% cobalt are required to indicate on the device or a warning label to the presence of cobalt as a potential CMR (carcinogenic, mutagenic, reproductive toxin) substance. Interest is in the level of cobalt (Co) which may be present as a trace contaminant within stainless steels alloys used for medical devices. For instance, historical data suggests that for several stainless alloy families such as 300 series, 400 series. etc., the amount of cobalt can vary between 0.05-0.40 wt% in a traditional melt exceeding the EU MDR proposed limits. With improved melting cleanliness protocols and effective scrap reuse and recycling controls, Carpenter Technology has been successful in limiting the presence of Cobalt less than 0.10 wt% in several commonly used stainless-steel alloys for the medical device industry.
Another instance is the development of Nitinol additive manufacturing. It has been widely recognized that 3D printing Nitinol—a key medical alloy—with effective translation of shape memory and super elasticity properties is a challenge. 3D printed Nitinol has limited shape memory and superelasticity compared to the wrought materials. These material properties are extremely sensitive to subtle changes in alloy chemistry. At Carpenter Technology, we have been successful in producing high-quality inert gas-atomized Nitinol powders and have demonstrated effective translation of these properties for medical applications.
Barbella: How will medical materials science evolve over the next five years?
Lalwani: High-performance medical materials will be at the forefront for supporting and enabling the next generation of medical devices. The continued development of robotic platforms and minimally invasive surgical procedures will drive the need for smaller precision implants and surgical tools, in turn driving the innovation to meet the needs applications that demand high strength, corrosion resistance, tight tolerance, and enhanced machining materials. Further developments in additive manufacturing processes will focus on next-generation devices with intricate features and porosities and will need metal powders optimized for additive manufacturing. Large-scale production needs will include better powder management, handling, recyclability, and traceability controls, which can be achieved using Carpenter’s PowderLife powder management solutions. Additionally, regulatory bodies such as ASTM are working on developing powder specific standards for alloys typically used in wrought/cast forms beyond titanium, which will be important for the introduction of new material systems for 3D printing.
Scientists have developed a promising new weapon in the war against hospital-acquired infections. UCLA specialists are fine-tuning an anti-microbial barrier they created for implantable medical devices using zwitterionic material and ultraviolet light. Zwitterionic substances are comprised of molecules that possess an equal amount of cationic and anionic groups, thereby rendering them electrically neutral.
The UCLA team built the barrier by depositing a thin layer of zwitterionic material to a device surface and then bonding it to the underlying substrate through UV light irradiation. Early clin- ical results are encouraging—laboratory testing shows the surface treatment reduces biofilm growth by more than 80% and in some cases up to 93%, depending on the bacterial strain.
“The modified surfaces exhibited robust resistance against microorganisms and proteins, which is precisely what we sought to achieve,” Richard Kaner, a UCLA Dr. Myung Ki Hong professor of Materials Innovation, and senior research author, told the university’s news service earlier this year. “The surfaces greatly reduced or even prevented biofilm formation. Our early clinical results have been outstanding.”
Those results are based on 16 long-term urinary catheter users who switched to silicone devices containing the zwitterionic surface treatment. The modified catheter is the first product made by SILQ Technologies Corp., a UCLA spinout company Kaner founded out of his lab in April 2020. The catheter has been cleared for use by the U.S. Food and Drug Administration.
Materials science is key to medtech innovation. New and improved manufacturing materials have led to advancements such as bioprinting, skin-friendly adhesives, shape memory plastics, bioactive glass (orthopedic repair), and bioresorbable stents.
MPO’s materials feature examines the latest trends and challenges in medtech materials science, as well as the factors driving innovation in this field. Gaurav Lalwani, global medical applications engineering lead at Carpenter Technology, was among the experts interviewed for this story; his full input is provided in the following Q&A:
Michael Barbella: What are the latest trends in medical device materials? What factors are driving these trends?
Gaurav Lalwani: Medical devices are an active area of high impact innovation and there are several trends that have made a positive impact on improving patient outcomes. The two most important trends are additive manufacturing (3D printing) and robotic/minimally invasive surgeries. Additive manufacturing provides accessibility to novel implant designs that can provide design features not possible using traditional manufacturing, such as creation of porous implants for enhanced osteointegration and patient-specific implants along with production of complex device designs that are either not possible or too expensive to produce using subtractive manufacturing. Robotic and minimally invasive surgeries are focused on reducing post operational recovery times by enabling precision laparoscopic surgical procedures via a small incision. Improving patient outcomes is the focus of all innovation in medical devices and availability of raw materials to enable support and development is critical.
Barbella: What factors are driving innovation in medical device materials science?
Lalwani: Innovation in medical device materials is directly driven by the need to support and enable the latest device designs and trends. Robotic and minimally invasive surgeries need smaller devices and tools, which drive the need for high strength and tighter tolerance raw material feedstock. Additionally, to improve productivity and eliminate machining scrap, efforts are underway to reduce the residual stress in stainless steel products. Carpenter Technology currently supplies a portfolio of high strength tight tolerance premium stainless, cobalt and titanium alloys—for example, the enhanced machining Project 70+ stainless steel—and is also investigating production of novel low-residual stress 17-4 stainless steel products. Regulatory changes can also drive innovation in medical materials. For instance, the up classification of cobalt and changes in EUMDR led Carpenter to further optimize its melt protocols and scrap streams to enable production of commonly used stainless steel alloys with Cobalt below 0.10 wt% to be EU MDR compliant.
Barbella: What material challenges are associated with medical device miniaturization and how can these challenges be overcome?
Lalwani: Miniaturization of devices for robotic and minimally invasive surgeries require high strength alloys with tight tolerance and advanced machining operations that rely on minimal run-out to ensure consistency, minimal user involvement, tight tolerances, and repeatability from part to part. Carpenter is currently developing a minimum residual stress 17-4PH bar stock for some unique medical machining applications to ensure consistency from bar-to-bar. Ultimately, this would ensure minimal deflection during the machining operation and open the door to advanced, hands-off manufacturing of complex and thin-wall geometries. As trends towards minimally invasive surgeries continue, the need for smaller devices will require both the precision of advanced machining and the characteristics of next-generation materials, where more performance is packed into a smaller unit volume. A great example of this is Carpenter’s BioDur 108 alloy, which takes the performance expectations of an industry standard (vacuum melted 316 stainless) and increases strength, corrosion resistance, fatigue, and biocompatibility (Ni and Co removal for regulatory and allergic concerns).
Barbella: How have materials suppliers managed the supply chain challenges prompted by the pandemic, and what lessons (changes) might they implement going forward to avoid future problems/issues?
Lalwani: While COVID-19 has certainly caused significant challenges to supply chain management of raw materials, positive changes to the engagement between OEMs, contract manufacturers and material suppliers have been extensive. As one of the larger producers of both metal implant and instrument materials in the medical device space, we have significantly increased our strategic involvement, partnerships, and communication within this space, resulting in a much better understanding of the overall needs of the market. This has resulted in new and differentiated programs at Carpenter, such as strategic staging of Work-in-Process (WIP) materials to help stabilize lead-times during uncertain demand times, stocking opportunities at our regional warehouses to aid with just-in-time (JIT) delivery requests, and more contractual agreements with directed buy programs. The initiatives help OEMs manage and shore up supply continuity regardless of their strategy to manufacture in-house, outsource machining, or some combination of both. The pandemic has certainly caused underlying challenges to rise to the surface and overall, at least in the metals space, has helped initiate positive changes. Building on that momentum, we believe that working together and increasing transparency between OEMs, CMs, and material suppliers will help us all navigate the current demand uncertainly better and hope for continued progression in the years to come.
Barbella: In what ways has the COVID-19 pandemic spurred medical materials innovation, if at all?
Lalwani: There has been an interest in developing antimicrobial materials over the last several years. Materials systems containing additional elements such as silver and copper introduced in the base alloy chemistry or as an external coating have been extensively investigated. Due to COVID-19, these initiatives have a renewed focus and remain an active area of research with OEMs and contract manufacturers introducing new devices with improved antimicrobial surfaces.
Barbella: How can materials help improve and/or achieve medical device sustainability?
Lalwani: Materials play a critical role in improving medical device sustainability. For instance, 3D printed medical devices with porous architectures that allow for better osteointegration have been reported to improve initial fracture stabilization and minimize aseptic loosening of implants. High strength corrosion resistant alloys with enhanced fatigue performance improves implant life and reduces the risk of revision surgeries. Alloys that exhibit enhanced EM shielding are used in cardiovascular applications for pacemakers cans and are proven to enhance performance and longevity.
Barbella: Please discuss an instance (example) of an innovative material solution your company came up with to meet a challenging customer request.
Lalwani: Under new EU Medical Devices Regulation (EU MDR, 2017/745), medical devices that contain more than 0.10 wt% cobalt are required to indicate on the device or a warning label to the presence of cobalt as a potential CMR (carcinogenic, mutagenic, reproductive toxin) substance. Interest is in the level of cobalt (Co) which may be present as a trace contaminant within stainless steels alloys used for medical devices. For instance, historical data suggests that for several stainless alloy families such as 300 series, 400 series. etc., the amount of cobalt can vary between 0.05-0.40 wt% in a traditional melt exceeding the EU MDR proposed limits. With improved melting cleanliness protocols and effective scrap reuse and recycling controls, Carpenter Technology has been successful in limiting the presence of Cobalt less than 0.10 wt% in several commonly used stainless-steel alloys for the medical device industry.
Another instance is the development of Nitinol additive manufacturing. It has been widely recognized that 3D printing Nitinol—a key medical alloy—with effective translation of shape memory and super elasticity properties is a challenge. 3D printed Nitinol has limited shape memory and superelasticity compared to the wrought materials. These material properties are extremely sensitive to subtle changes in alloy chemistry. At Carpenter Technology, we have been successful in producing high-quality inert gas-atomized Nitinol powders and have demonstrated effective translation of these properties for medical applications.
Barbella: How will medical materials science evolve over the next five years?
Lalwani: High-performance medical materials will be at the forefront for supporting and enabling the next generation of medical devices. The continued development of robotic platforms and minimally invasive surgical procedures will drive the need for smaller precision implants and surgical tools, in turn driving the innovation to meet the needs applications that demand high strength, corrosion resistance, tight tolerance, and enhanced machining materials. Further developments in additive manufacturing processes will focus on next-generation devices with intricate features and porosities and will need metal powders optimized for additive manufacturing. Large-scale production needs will include better powder management, handling, recyclability, and traceability controls, which can be achieved using Carpenter’s PowderLife powder management solutions. Additionally, regulatory bodies such as ASTM are working on developing powder specific standards for alloys typically used in wrought/cast forms beyond titanium, which will be important for the introduction of new material systems for 3D printing.