Industrial sterilization is primarily used for medical and healthcare products including a wide range of single-use medical products and devices. Historically, sterilization is mostly done using gamma sources. However, recently we observe a transition to accelerator-based sterilization, specifically uses of e-beam and X-ray. Lack of the knowledge of radiation effects on polymers for e-beam and X-ray is one of the reasons to impede the spreading use of these technologies. Therefore, the purpose of this proposal is to expand our understanding of radiation effects on polymer materials commonly used in medical devices by comparing gamma, e-beam, and X-ray irradiation. The increased access to accelerator-based sterilization, in addition to other sterilization methods, will have a collateral benefit aligned to UN Sustainable Development Goals, specifically SDG 3 (good health and well-being), SDG 9 (industry, innovation and infrastructure), and SDG 12 (responsible consumption and production).
The overall objective of this CRP is to expand our understanding of radiation effects on polymer materials common for medical devices by comparing gamma, e-beam, and x-ray irradiation. The research outputs covering material and mechanical studies, dosimetry, process control and technology will include peer-reviewed journal articles, book chapters, reports, user cases, technical presentations, etc.
We propose the studies to focus on the polymers commonly used in medical industry, including low density polyethylene (LDPE), polypropylene (PP), poly (ether-block-amide) thermoplastic elastomers (PEBA), polytetrafluoroethylene (PTFE), and others. However, biopolymers (e.g., biodegradable polyesters like polylactic acid, polyglycolic acid, polysaccharides, and collagen) can also be of interest. Bioresorbable implants sterilization or crosslinking applications such as for ultra-high molecular weight polyethylene (UHMWPE) are of particular interest, where differences in irradiation conditions are expected to introduce a significant difference in critical attributes of products. Such effects are believed less likely to occur for the majority of product currently sterilized using ionizing radiation. For example, it has been reported by a patent of IMEDEX Biomateriaux [2] that collagen presents significantly different biodegradation resistances, depending on the radiation mode (e-beam versus gamma-ray). The effect of additives (e.g., anti-oxidants, stabilizers, friction lubricant, plasticizers), mainly present in dominant polymers, should also be considered (investigation of radiation-induced by-products and/or leachables).
Physical and Chemical analysis of samples irradiated with:
- gamma sources (Co-60)
- e-beam of various energy and current (both pulsed and continuous)
- X-ray
The dose levels should be based on the purpose for the irradiation process (25 - 100 kGy). The effect of different dose rates should also be considered.
Biocompatibility studies of samples irradiated with:
- gamma sources (Co-60)
- e-beam of various energy and current (both pulsed and continuous)
- X-ray
The dose levels should be based on the purpose for the irradiation process (25 - 100 kGy).
Ageing studies of samples irradiated with:
- gamma sources (Co-60)
- e-beam of various energy and current (both pulsed and continuous)
- X-ray
The dose levels should be based on the purpose for the irradiation process (25 - 100 kGy).
Studies of functionalities of the whole product, often consisting of several different polymers, irradiated with:
- gamma sources (Co-60)
- e-beam of various energy and current (both pulsed and continuous)
- X-ray
The dose levels should be based on the purpose for the irradiation process (25 - 100 kGy).
Models and simulations of irradiation effects in polymers assuming 25-100 kGy dose.