Effect of Vaporized Hydrogen Peroxide and Nitrogen Dioxide Sterilization on Nitinol.

Background: Nitinol is used as the structural framework in numerous types of medical devices (e.g., guidewires, transcatheters, stents). The desire to understand the material compatibility of nitinol with vaporized hydrogen peroxide (VH2O2) and nitrogen dioxide (NO2) sterilization is increasing in healthcare technology. As a result of increased regulatory pressure and capacity limitations related to ethylene oxide (EO) sterilization, the industry is seeking alternative, sustainable sterilization options. Objective: This study sought to characterize the corrosion resistance of nitinol metal alloy wire when exposed to varying levels of VH2O2 and NO2 sterilization. Methods: Scanning electron microscopy (SEM) imaging and energy-dispersive X-ray spectroscopy (EDS) scans were performed to understand the effects of VH2O2 and NO2 sterilization treatments on the surface morphology and chemical composition of nitinol. Results: From the SEM-EDS results, no notable difference was observed when comparing VH2O2 and NO2 test samples with nonsterile control samples. In addition, cyclic potentiodynamic polarization measurements were performed per ASTM F2129-19a to determine corrosion susceptibility. No considerable changes were detected in the electrochemical potential after VH2O2 and NO2 sterilization treatments, when compared with the nonsterile control samples. Conclusion: SEM-EDS and corrosion test results indicated no considerable changes in the surface properties or electrochemical potential of the sterilized samples compared with the nonsterilized control samples. Therefore, nitinol metal showed promising results for compatibility with VH2O2 and NO2 sterilization.

Radiation and ethylene oxide terminal sterilization experiences with drug eluting stent products.

Radiation and ethylene oxide terminal sterilization are the two most frequently used processes in the medical device industry to render product within the final sterile barrier package free from viable microorganisms. They are efficacious, safe, and efficient approaches to the manufacture of sterile product. Terminal sterilization is routinely applied to a wide variety of commodity healthcare products (drapes, gowns, etc.) and implantable medical devices (bare metal stents, heart valves, vessel closure devices, etc.) along with products used during implantation procedures (catheters, guidewires, etc.). Terminal sterilization is also routinely used for processing combination products where devices, drugs, and/or biologics are combined on a single product. High patient safety, robust standards, routine process controls, and low-cost manufacturing are appealing aspects of terminal sterilization. As the field of combination products continues to expand and evolve, opportunity exists to expand the application of terminal sterilization to new combination products. Material compatibility challenges must be overcome to realize these opportunities. This article introduces the reader to terminal sterilization concepts, technologies, and the related standards that span different industries (pharmaceutical, medical device, biopharmaceuticals, etc.) and provides guidance on the application of these technologies. Guidance and examples of the application of terminal sterilization are discussed using experiences with drug eluting stents and bioresorbable vascular restoration devices. The examples provide insight into selecting the sterilization method, developing the process around it, and finally qualifying/validating the product in preparation for regulatory approval and commercialization. Future activities, including new sterilization technologies, are briefly discussed.

Sterility Assurance Across-Sectors-New Paradigms and Tools.

The sterility assurance community is facing significant challenges. A relatively recent challenge is the pressure on manufacturing supply chains resulting from the limited availability of capacity for terminal sterilization of healthcare products. The current challenge is finding solutions for innovative new products, especially biologics and combination products, that offer great promise for patients around the world. This challenge will become more prevalent in the future as products advance. This article frames new paradigms and tools being developed to address these challenges. Foundational principles and current realities from each sector are reviewed so that sterility assurance professionals have a solid base from which to build strategies.

Lumen gain and restoration of pulsatility after implantation of a bioresorbable vascular scaffold in porcine coronary arteries.

OBJECTIVES: Using intravascular ultrasound (IVUS) and histomorphometry, this study sought to evaluate the potential of nonatherosclerotic porcine coronary arteries to undergo progressive lumen gain and a return of pulsatility after implantation with an everolimus-eluting bioresorbable vascular scaffold (BVS). BACKGROUND: Unique benefits such as lumen gain and restored vasomotion have been demonstrated clinically after treatment with BVS; however, a more rigorous demonstration of these benefits with a randomized clinical trial has not yet been conducted. METHODS: Seventy nonatherosclerotic swine received 109 everolimus-eluting BVS and 70 everolimus-eluting metal stents randomized among the main coronary arteries. Arteries were evaluated in vivo by angiography and IVUS and post-mortem by histomorphometry at time points from 1 to 42 months. RESULTS: From 1 to 6 months, both BVS- and everolimus-eluting metal stent-implanted arteries demonstrated stable lumen areas (LAs). From 12 months to 42 months, there was a progressive increase in the LA of arteries implanted with a BVS as assessed by histomorphometry and IVUS. This lumen gain in the implanted segment corresponded to an increase in the reference vessel LA. Normalization in the in-segment LA (LA:reference vessel LA) was observed qualitatively by angiography and quantitatively by IVUS. Additionally, BVS-implanted arteries demonstrated restored in-segment pulsatility on the basis of IVUS assessment of the differences in the mid-scaffold area between end-diastole to end-systole. CONCLUSIONS: Starting at 12 months, BVS-implanted porcine coronary arteries underwent progressive lumen gain and showed restored pulsatility. These benefits demonstrated preclinically may translate into improvements in long-term clinical outcomes for patients treated with BVS compared with conventional drug-eluting stents.