Over the past several decades there has been relatively little innovation in the arena of medical device sterilization. Ethylene oxide (ETO) and gamma irradiation (? irradiation) are the only technologies commercially available for medical devices. In particular, synthetic polymeric medical devices are sterilized almost exclusively by ETO due to undesirable chemical degradation and/or mechanical changes caused by gamma-irradiation. Gamma-irradiation requires cobalt-60 and these facilities are generally housed in large industrial or research institutions that have high operating costs associated with this technology. Suture manufacturers have expressed interest in moving from this process due to the short- and long-term negative effects of residual ETO in sterilized products, the fact that it s a recognized carcinogen, and the precautionary measures needed to operate around the toxic and explosive nature of ETO. Recently the EPA and other government agencies have started to monitor ETO in response to personal and environmental issues. Thus, development of alternative sterilization processes that are capable of achieving validated sterility assurance levels of 10-6 (SAL6) - the benchmark for medical devices - without the use of dangerous ETO or damaging ?-irradiation is of great importance. The current proposed effort aims to advance NovaSterilis'supercritical carbon dioxide (scCO2) sterilization technology and produce a viable method to sterilize suture materials while maintaining suture mechanical properties. The NovaSterilis process is environmentally friendly and uses only carbon dioxide and a chemical sterilant that breaks down into benign compounds during the process. The Phase I work has established the optimal conditions using supercritical carbon dioxide (scCO2) sterilization technology that have no adverse effects on the mechanical properties and no cytotoxicity of sutures sterilized to SAL6 under ISO guidelines. Thus, the Phase I has allowed us to show feasibility of supercritical carbon dioxide as a method of overcoming the current limitations on sterilization options currently used for sutures. Terminal sterilization using our supercritical carbon dioxide process has the potential to add a one-step validated terminal sterilization process to suture manufacturers and distributors while decreasing the costs and burdens associated with current ethylene oxide sterilization processes. NovaSterilis is ready to begin Phase II in vivo and in vitro advanced testing to assess commercial- readiness of scCO2-sterilized suture materials to provide the medical device industry with a less toxic and more gentle alternative to current sterilization technologies. NovaSterilis, the lead company for this project, will pair its team of experienced engineers, chemists and biologists, including consultant Prof. CC Chu of Cornell University, a recognized expert in the arena of suture development, with additional experts in animal toxicity and efficacy testing, scale-up and shelf-life testing. Te Phase I partnership has proven highly successful, and the logical next steps towards commercialization will be accomplished in the Phase II. The primary goal is to ensure the safety and efficacy of sutures sterilized using NovaSterilis supercritical carbon dioxide technology through in vivo and in vitro commercial-readiness testing.

Public Health Relevance

Supercritical carbon dioxide sterilization of commercial suture materials presents an environmentally safe technique that does not require harsh conditions currently in use by the suture industry. The future of wound healing is affected by the development of advanced synthetic wound closure materials that will not stand up to current sterilization regimens. There is a clear need in the health care industry for both new materials and safe, innovative approaches to materials sterilization that will eliminate any opportunity for disease transmission.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Small Business Innovation Research Grants (SBIR) - Phase II (R44)
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Special Emphasis Panel (ZRG1-SBIB-Q (11))
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Cole, Alison E
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Novasterilis, Inc.
United States
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