Risks of Using Sterilization by Gamma Radiation: The Other Side of the Coin

Abstract

The standard sterilization method for most medical devices over the past 40 years involves gamma irradiation. During sterilization, gamma rays efficiently eliminate microorganisms from the medical devices and tissue allografts, but also significantly change molecular structure of irradiated products, particularly fragile biologics such as cytokines, chemokines and growth factors. Accordingly, gamma radiation significantly alters biomechanical properties of bone, tendon, tracheal, skin, amnion tissue grafts and micronized amniotic membrane injectable products. Similarly, when polymer medical devices are sterilized by gamma radiation, their physico-chemical characteristics undergo modification significantly affecting their clinical use.Several animal studies demonstrated that consummation of irradiated food provoked genome instability raising serious concerns regarding oncogenic potential of irradiated consumables. These findings strongly suggest that new, long-term, prospective clinical studies should be conducted in near future to investigate whether irradiated food is safe for human consumption. In this review, we summarized current knowledge regarding molecular mechanisms responsible for deleterious effects of gamma radiation with focusing on its significance for food safety and biomechanical characteristics of medical devices, and tissue allografts, especially injectable biologics.

The role of environmental factors to transmission of SARS-CoV-2 (COVID-19)

“…Gamma CO60 with a dose of 10 KG can sterilize the N95 mask used in SARS-COV environments, and kill the virus (Feldmann et al 2019). However, high doses of radiation may damage the fibers of the mask and allow air to pass through without purification, but it does not have secondary radiation and its side effects (Harrell et al 2018). Hydrogen peroxide is also a useful antiviral and has no adverse effects on the respiratory tract (Viscusi et al 2009).…”

Vancomycin-releasing cross-linked collagen sponges as wound dressings

“…Since fish-derived collagen exhibits a lower melting temperature and less reproducible properties than mammal collagen [17], it must be crosslinked in order to obtain a product that exhibits reproducible properties [14]. A further reason for crosslinking is to enhance durability during the sterilization process since non-crosslinked collagen is significantly degraded upon exposure to gamma rays [18]. Therefore, if gamma sterilization is a part of the fabrication of the ready-touse medical device, crosslinking provides a reliable way to preserve the properties of both fish and mammal collagen [3,19].…”

Disposable N95 Masks Pass Qualitative Fit-Test But Have Decreased Filtration Efficiency after Cobalt-60 Gamma Irradiation

“…Significant literature exists supporting the use of gamma radiation as a sterilization method, with viral inactivation of SARS-CoV reported at doses of at most 10 kGy [3], with other studies supporting 5 kGy for many types of viruses [4]. However, concerns have been raised about the radiation damaging the fiber material within the mask, specifically by causing cross-linking of polymers, leading to cracking and degradation during fitting and/or deployment [5,6].A set of 3M 8210 and 9105 masks were irradiated using MIT's 60 Co irradiator. Three masks of each type received 0 kiloGray (kGy), 10 kGy and 50 kGy of approximately 1.3 MeV gamma radiation from the circular cobalt sources, at a dose rate of 2.2kGy per hour.Following this sterilization procedure, the irradiated masks passed a OSHA Gerson Qualitative Fit Test QLFT 50 (saccharin apparatus) [7] when donned correctly, performed at the Brigham and Women's Hospital, in a blinded study repeated in triplicate.…”