Positive association between blood ethylene oxide levels and metabolic syndrome: NHANES 2013-2020

Purpose

The exposure of Ethylene oxide (EO) is linked to systemic inflammatory response and various cardiovascular risk factors. Hemoglobin's binding to ethylene oxide (HbEO) was used to measure serum EO level. This research aims to explore the association between metabolic syndrome (MetS) and HbEO, and between HbEO and components of metabolic syndrome.

Method

This research included 1842 participants from 2013 to 2020 in National Health and Nutrition Examination Survey (NHANES) database. Weighted logistic regression models were used to analyze the relationship between HbEO and metabolic syndrome risk, using odds ratio (OR) and 95% confidence interval (CI). The restricted cubic spline plot explores whether there is a dose-response relationship between HbEO and MetS risk. Subgroup analysis was performed to analyze study heterogeneity.

Results

Significant differences were found in gender, educational level, marital status, diabetes status and hypertension among different groups (P < 0.001, P = 0.007, P = 0.003, P < 0.001, P < 0.001, respectively). The serum HbEO level exhibited positive correlation with metabolic syndrome risk in Q2 level (OR=1.64, 1.04~2.48), Q3 level (OR=1.99, 1.29~3.08), and Q4 level (OR=2.89, 1.92~4.34). The dose-response association suggested a possible linear association between serum HbEO and metabolic syndrome risk (P-overall=0.0359, P-non-linear=0.179). L-shaped association was found between HbEO and the risk of MetS in female population, obese population and mid-age and elder population (P-overall<0.001, P-non-linear=0.0024; P-overall=0.0107, P-non-linear=0.0055 P-overall<0.001 P-non-linear=0.0157).

Conclusion

This study indicates a linear correlation between MetS and HbEO, with MetS risk escalating as HbEO levels increase. The prevalence of MetS varies depending on BMI, age and gender, and these factors can also influence MetS prevalence when exposed to EO.

Microscopic Understanding of Interfacial Performance and Antifoaming Mechanism of REP Type Block Polyether Nonionic Surfactants

In many practical applications involving surfactants, achieving defoaming without affecting interfacial activity is a challenge. In this study, the antifoaming performance of REP-type block polymer nonionic surfactant C12EOmPOn was determined, and molecular dynamics simulation method was employed to investigate the molecular behaviors of surfactants at a gas/water interface, the detailed arrangement information of the different structural segments of the surfactant molecules and the inter-/intra-interactions between all the structural motifs in the interfacial layer were analyzed systematically, by which the antifoaming mechanisms of the surfactants were revealed. The results show that the EO and PO groups of REP-type polyether molecules are located in the aqueous phase near the interface, and the hydrophobic tails distribute separately, lying almost flat on the gas/water interface. The interaction between the same groups of EOs and POs is significantly stronger than with water. REP block polyethers with high polymerization degrees of EO and PO are more inclined to overlap into dense layers, resulting in the formation of aggregates resembling "oil lenses" spreading on the gas/water interface, which exerts a stronger antifoaming effect. This study provides a smart approach to obtaining efficient antifoaming performance at room temperature without adding other antifoam ingredients.

The Impacts of the Sterilization Method and the Electrospinning Conditions of Nanofibrous Biodegradable Layers on Their Degradation and Hemocompatibility Behavior

The use of electrospun polymeric biodegradable materials for medical applications is becoming increasingly widespread. One of the most important parameters regarding the functionality of nanofiber scaffolds during implantation and the subsequent regeneration of damaged tissues concerns their stability and degradation behavior, both of which are influenced by a wide range of factors (the properties of the polymer and the polymer solution, the technological processing approach, the sterilization method, etc.). This study monitored the degradation of nanofibrous materials fabricated from degradable polyesters as a result of the sterilization method applied (ethylene oxide and gamma irradiation) and the solvent system used to prepare the spun polymer solution. Aliphatic polyesters PCL and PLCL were chosen for this study and selected with respect to the applicability and handling in the surgical setting of these nanofibrous materials for vascular bandaging. The results revealed that the choice of solvent system exerts a significant impact on degradation during sterilization, especially at higher gamma irradiation values. The subsequent enzyme-catalyzed degradation of the materials following sterilization indicated that the choice of the sterilization method influenced the degradation behavior of the materials. Whereas wave-like degradation was evident concerning ethylene oxide sterilization, no such behavior was observed following gamma-irradiation sterilization. With concern for some of the tested materials, the results also indicated the potential for influencing the development of degradation within the bulk versus degradation from the surface of the material. Both the sterilization method and the choice of the spinning solvent system were found to impact degradation, which was observed to be most accelerated in the case of PLCL (L-lactide-co-caprolactone copolymer) electrospun from organic acids and subsequently sterilized using gamma irradiation. Since we planned to use these materials in cardiovascular applications, it was decided that their hemocompatibility would also be tested. The results of these tests revealed that changes in the structures of the materials initiated by sterilization may exert thrombogenic and anticoagulant impacts. Moreover, the microscopic analysis suggested that the solvent system used in the preparation of the materials potentially affects the behavior of erythrocytes; however, no indication of the occurrence of hemolysis was detected.

CO2-Free Ethylene Oxide Production via Liquid-Phase Epoxidation with Fe2O3/MSM Catalyst

In this study, we present an approach for ethylene oxide (EO) production that addresses environmental concerns by eliminating greenhouse gas emissions. Our catalyst, Fe2O3/MSM, was synthesized using a hydrothermal method, incorporating Fe2O3 nanoparticles into a well-structured mesoporous silica matrix (MSM). We selected peracetic acid as the oxidant, enabling CO2-free EO production while yielding valuable by-products such as acetic acid, monoethylene glycol, and diethylene glycol. X-ray diffraction (XRD), X- ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyses confirmed the heteroatom structure of the catalysts and porosity, while Transmission electron microscopy (TEM) analysis provided insights into its morphology. Then, the synthesized catalyst was used in the liquid-phase epoxidation of ethylene for EO production. Our systematic experiments involved varying critical parameters such as temperature, ethylene to oxidant ratio, catalyst dosage, and solvent to optimize EO selectivity and ethylene conversion. The results of this study demonstrated an 80.2 % ethylene conversion to EO with an EO selectivity of 87.6 %. The production process yielded valuable by-products without CO2 emissions, highlighting its environmental friendliness.

Detrimental Effects of Sterilization Types on Single-Use Coronary Angioplasty Catheters for Reuse: An Electron Microscopic Study

Objective

Reuse of medical devices poses risks concerning technical issues and patient safety. In this study, we aimed to examine the structural changes in catheters that occur due to the reuse with the aid of electron microscopy.

Materials and Methods

The effects of hydrogen peroxide (HP) and ethylene oxide (EO) sterilization on four percutaneous transluminal coronary angioplasty (PTCA) catheters and control PTCA catheters were examined by scanning electron microscope (SEM). Each catheter sample was divided into four parts during the SEM examination, and a total of 20 pieces were examined. Catheters were reprocessed through every regular sterilization step and used solely for the study, not in patients. Statistical evaluations of histological scoring made on images obtained from scanning electron microscopic images were made using the GraphPad Prism 8 program.

Results

Electron microscopical examination showed that HP sterilization caused more robust and deeper lines compared to EO. These distortions increased directly with the increase in the reprocessing cycle. In EO, no significant damage was detected within five cycles in contrast to HP; however, the harmful effects of EO were seen over five cycles. Unprocessed samples had no damage. Outer and inner deterioration was significantly higher in the EO>5 group and HP>5 group than in the control group. However, the bacterial contamination score in the EO>5 group was higher than the control group.

Conclusion

Our findings showed that HP and EO sterilizations caused some deterioration in the inner and outer surfaces of PTCA catheter samples. We recommend reprocessing using EO, the least damaging method, when necessary, and paying attention not to exceed five cycles when necessary.

Association between blood ethylene oxide levels and periodontitis risk: a population-based study

Background

The etiopathogenesis of periodontitis is closely associated with environmental conditions. However, the relationship between ethylene oxide exposure and periodontitis risk remains unclear.

Methods

We selected qualified participants from National Health and Nutrition Examination Survey (NHANES) 2013-2014. Periodontitis was identified according to the criteria of the Community Periodontal Index (CPI), Centers for Disease Control and Prevention (CDC)/American Academy of Periodontology (AAP) definition. Ethylene oxide exposure was quantified by hemoglobin adducts of ethylene oxide (HbEO) levels. Log2-transformation was used to normalize HbEO levels. We designed three logistic regression models to explore potential relationship between HbEO and periodontitis. Restricted cubic spline (RCS) and subgroup analysis were also conducted with all covariates adjusted. We performed multivariable linear regression to appraise the association between the risk of periodontitis and different indicators of inflammation, including white blood cells, neutrophils, lymphocytes, and monocytes. Mediation analysis was subsequently performed to examine whether ethylene oxide exposure contributed to periodontitis development through systemic body inflammation.

Results

A total of 1,065 participants aged more than 30 were incorporated in this study. We identified that participants with higher HbEO levels showed increased risk of periodontitis after adjusting for all covariates (OR = 1.49, 95% CI: 1.14, 1.95, p = 0.0014). The results of subgroup analysis remained stable. The restricted cubic spline (RCS) curve also revealed a non-linear correlation between log2-transformed HbEO levels with the risk of periodontitis (p for nonlinear < 0.001). Mediation analysis indicated that HbEO level was significantly associated with four inflammatory mediators, with the mediated proportions of 14.44% (p < 0.001) for white blood cell, 9.62% (p < 0.001) for neutrophil, 6.17% (p = 0.006) for lymphocyte, and 6.72% (p < 0.001) for monocyte.

Conclusion

Participants with higher ethylene oxide exposure showed higher risk of periodontitis, which was partially mediated by systemic body inflammation. More well-designed longitudinal studies should be carried out to validate this relationship.

Cutaneous anaphylactoid reaction to polyoxyethylene hydrogenated castor oil in dogs

BACKGROUND

Polyoxyethylene hydrogenated castor oil (HCO ethoxylates) is a nonionic surfactant used as an excipient for ointments and injections in human and veterinary drugs. Several polyethylene glycol (PEG) derivatives can be obtained depending on the number of moles of ethylene oxide (EO). HCO ethoxylates have the potential to cause anaphylactoid reactions. There is little published information about these types of reactions in dogs.

OBJECTIVE

To determine the potential for HCO-ethoxylate-containing drugs to cause anaphylactoid reactions in dogs, employing intradermal testing (IDT) with various concentrations of HCO ethoxylates (HCO-25, -40, -60 and -80).

ANIMALS

Four healthy male laboratory dogs.

MATERIALS AND METHODS

We performed IDT with drugs containing HCO ethoxylates and HCO ethoxylates alone to determine threshold concentrations. The IDT scores and threshold concentrations were compared. Analysis of skin biopsies from IDT sites was used to measure the percentage of degranulated mast cells. The effect of histamine at IDT sites was investigated by pre-treatment with an antihistamine.

RESULTS

All HCO-ethoxylate-containing drugs caused a wheal-and-flare reaction. The threshold concentrations (0.001% and 0.00001%) of each HCO-ethoxylate depended on the number of moles of EO (p < 0.05). Mast cell degranulation was enhanced by all HCO ethoxylates. The HCO-60-induced reaction was suppressed by an oral antihistamine.

CONCLUSIONS AND CLINICAL RELEVANCE

The threshold concentration can serve as a consideration for developing safe new drug formulations and for clinical decision-making around using drugs containing PEG derivatives. IDT is useful to predict the risk of adverse effects. Antihistamines could demonstrate a prophylactic effect.

Integrative literature review: Ethylene oxide exposure signs and symptoms

BACKGROUND

Although ethylene oxide (EtO) gas is designated as a human carcinogen, extant literature reports mixed findings on the health effects of exposure. The disparate findings may reflect industry bias as many studies were funded by a large chemical industry lobby.

OBJECTIVE

To conduct an integrative review of studies free from industry bias to facilitate compilation of a comprehensive list of reported signs and symptoms of EtO exposure.

METHODS

We reviewed 1887 papers of which 42 articles met inclusion criteria. The authors conducted this review in accordance with PRISMA guidelines. The presence of bias was assessed using Joanna Briggs Institute checklists.

RESULTS

Non-industry biased literature confirmed serious adverse health effects associated with EtO exposure at the occupational, hospital, and community level. EtO represents a carcinogen, neurotoxin, and respiratory irritant.

CONCLUSION

After removal of industry-biased studies, EtO was unequivocally found to pose a threat to human health. There remains a gap in the number of studies examining community-level exposure, which is essential to understanding the impact of EtO. Given that EtO-emitting facilities are concentrated in diverse and disadvantaged communities, further study of EtO exposure health effects is warranted to inform public policy on toxic air emissions.

Influence of Ethylene Oxide and Gamma Irradiation Sterilization Processes on the Properties of Poly-L-Lactic-Acid (PLLA) Materials

In order to encourage the substitution of petrochemical polymers in medical technology with sustainable, bio-based materials, there is an urgent need for further investigations, especially data regarding their sterility performance. Within the scope of the investigations, selected material properties of poly-L-lactic-acid (PLLA), a specific type of poly(lactic-acid) (PLA), were analyzed before and after sterilization (using ethylene oxide or gamma irradiation) in order to investigate deviations in its chemical structure, wettability, optical, and mechanical properties. In particular, parameters such as molecular weight, complex viscosity, tensile strength, water contact angle, and color were discussed. Sterilization temperatures close to the glass transition of PLA, high humidity, and interactions with the ethylene oxide molecules have resulted in an increase in crystallinity, a decrease in elongation at break, and in some cases, a variation in wettability. As a consequence of exposure to high-energy radiation, the material's toughness is reduced due to chain scission, which is manifested through a decrease in molecular weight, an increase in crystallinity, and a partial change in surface energy. For the selected PLLA-materials (Luminy® L130, NP HT 202, and NP HT 203), ethylene oxide sterilization resulted in a comparatively minor variation in the characteristics behavior, and was chosen as the preferred method.

Assessment of Physicochemical Parameters and Contaminants in Herbal Dietary Supplements Used in the Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease is a complex disorder characterized by chronic gastrointestinal inflammation. Thus, patients prefer to use herbal dietary supplements containing turmeric, Indian frankincense, green chiretta, and black pepper in an attempt to cope better with their chronic condition. The dietary supplements' dosage forms and herbal ingredients were assessed in terms of the products' physicochemical parameters (weight uniformity, friability, disintegration, rupture test, tablet's breaking force, and powder flowability) in view of the USP-NF requirements. In addition, contaminants such as organic solvents and ethylene oxide were evaluated using gas chromatography. Assessment of gluten via an Enzyme-Linked Immunosorbent Assay was also performed. Most of the products met USP requirements. The high average weight of one multicomponent tablet sample with a high breaking force value can explain the observed negative results of the disintegration test. A total of 26% of samples tested positive for gluten, but the most alarming fact is that the ethylene oxide levels found in two samples were up to 30 times higher than the EU limit. Accordingly, dietary supplement quality control is of fundamental importance.

Comparative analysis of 3 pollen sterilization methods for feeding bumble bees

Pollen is an essential component of bee diets, and rearing bumble bees (Bombus spp.) for commercial use necessitates feeding pollen in mass quantities. This pollen is collected from honey bee (Apis mellifera L.) colonies because neither an artificial diet nor an economical, large-scale pollen collection process from flowers is available. The provenance of honey bee-collected pollen is often unknown, and in some cases has crossed international borders. Both deformed wing virus (DWV) and the fungal pathogen Ascosphaera apis (Claussen) Olive & Spiltoir (cause of chalkbrood disease); occur in honey bee-collected pollen, and infections have been observed in bumble bees. We used these pathogens as general surrogates for viruses and spore-forming fungal diseases to test the efficacy of 3 sterilization methods, and assessed whether treatment altered pollen quality for the bumble bee. Using honey bee-collected pollen spiked with known doses of DWV and A. apis, we compared gamma irradiation (GI), ozone fumigation (OZ), and ethylene oxide fumigation (EO) against an untreated positive control and a negative control. Following sterilization treatments, we tested A. apis spore viability, detected viral presence with PCR, and tested palatability to the bumble bee Bombus impatiens Cresson. We also measured bacterial growth from pollens treated with EO and GI. GI and EO outperformed OZ treatment in pathogen suppression. EO had the highest sterilizing properties under commercial conditions and retained palatability and supported bee development better than other treatments. These results suggest that EO sterilization reduces pathogen risks while retaining pollen quality as a food source for rearing bumble bees.

Influence of Disinfection Methods on Cinematographic Film

Microbiological contamination of cinematographic films can cause damage and loss of image information. A large part of the films is made with the base of cellulose triacetate, which has been used from the 1940s until today. Cellulose triacetate is relatively resistant to common organic solvents, but some types of microorganisms can contribute to its faster degradation. In this work, we tested four types of disinfectants suitable for mass disinfection and sufficiently effective against various types of microorganisms. Butanol vapours, a commercial mixture of alcohols (Bacillol^® AF), Septonex^® (an aqueous solution of [1-(ethoxycarbonyl)pentadecyl] trimethylammonium bromide) and ethylene oxide applied as a gas mixed with carbon dioxide were tested. Samples of a commercial film made of cellulose triacetate were disinfected. The samples were aged for 56 days at 70 °C and 55% RH. Changes in optical, mechanical and chemical properties were studied. None of the disinfectants affected the change in the degree of substitution. For samples disinfected with Bacillol^® AF (alcohol mixture), part of the plasticiser (triphenyl phosphate) was extracted and the intrinsic viscosity of the cellulose triacetate solution was reduced after ageing. A slight decrease in intrinsic viscosity also occurred after disinfection with ethylene oxide. Compared to the non-disinfected samples, butanol vapours and Septonex^® appear to be the most gentle disinfectants for the cellulose triacetate film base, within the studied parameters.

Does First-Use Syndrome Happen During Apheresis? A Case Report

Steam, dry heat, radiation, ethylene oxide gas, evaporated hydrogen peroxide, and many other sterilization methods are used to sanitize medical equipment (e.g., chlorine dioxide gas, nitrogen dioxide, and vaporized peracetic acid). The benefits of ethylene oxide (EO) are its great processing capabilities, high ionic conductivity, high flexibility, low cost, and exceptional adhesive qualities. Patients on hemodialysis, those undergoing extracorporeal photopheresis, and plasmapheresis donors have all reported allergic reactions to EO. Differentiating between IgE-mediated anaphylaxis and anaphylactoid reactions is often impossible in practice due to the wide range of clinical symptoms. The infrequency of EO reactions coupled with healthcare personnel's lack of familiarity with this clinical phenomenon may result in their underdiagnosis. We describe the case of a platelet donor who developed an allergy, while donating at a transfusion facility, due to an ethylene oxide-sterilized apheretic kit. We aim to draw attention to the fact that care should be given while handling cases of this nature as they can become life-threatening.

Sterilization effects on poly(glycerol dodecanedioate): A biodegradable shape memory elastomer for biomedical applications

Biodegradable shape memory polymers provide unique regenerative medicine approaches in minimally invasive surgeries. Once heated, thermally responsive shape memory polymer devices can be compressed, programmed to fit within a small profile, delivered in the cold programmed state, and expanded when heated to body temperature. We have previously developed a biodegradable shape memory elastomer (SME), poly(glycerol dodecanedioate) (PGD), with transition temperatures near 37°C exhibiting nonlinear elastic properties like numerous soft tissues. Using SMEs in the clinic requires disinfection and sterilization methods that conserve physiochemical, thermomechanical, and shape recovery properties. We evaluated disinfection protocols using 70% ethanol and UV254 nm for research applications and ethylene oxide (EtO) gas sterilization for clinical applications. Samples disinfected with ethanol for 0.5 and 1 min showed no changes in physiochemical material properties, but after 15 min showed slower recovery rates than controls (p < .05). EtO sterilization at 54.4°C decreased transition temperatures and shape recovery rate compared to EtO sterilization at 37.8°C (p < .01) and controls (p < .05). Aging samples for 9 months in a vacuum desiccator significantly reduced shape recovery, and the recovery rate in EtO sterilized samples compared to controls (p < .001). Cytotoxicity testing (ISO-10993.5C:2012) revealed media extractions from EtO sterilized samples, sterilized at 37.8°C, and high-density polyethylene negative control samples exhibit lower cytotoxicity (IC50) than Ethanol 1 min, UV 2 h, and EtO 54.4°C. Cell viability of NIH3T3 fibroblasts on sterilized surfaces was equivalent on EtO 37.7°C, EtO 54.4°C and Ethanol sterilized substrates. Finally, chromogenic bacterial endotoxin testing showed endotoxin levels were below the FDA prescribed levels for devices contacting blood and lymphatic tissues for ethanol 1 min, UV 120 min, EtO 37.7°C, EtO 54.4°C. These findings outline various disinfection and sterilization processes for research and pre-clinical application and provide a pathway for developing custom sterilization cycles for the translation of biomedical devices utilizing PGD shape memory polymers.

Ethylene oxide-type hypersensitivity reactions in G-CSF mobilized, peripheral blood hematopoietic progenitor cell donors and review

BACKGROUND

Ethylene oxide (EtO) is a volatile, ringed toxic ether used to sterilize heat-labile plastics including apheresis sets. In the 1980s, EtO-associated severe hypersensitivity reactions during hemodialysis led to widespread adoption of alternative sterilization for dialysis kits but not apheresis tubing sets. We now report several cases of EtO-type hypersensitivity reactions in autologous donors undergoing hematopoietic progenitor cell collection (HPCC).

MATERIALS AND METHODS

A 10-year retrospective review of allergic EtO-type reactions in adults undergoing HPCC on the COBE Spectra and SPECTRA Optia was performed. Donor medical history and absolute eosinophil counts were compared between cases and 34 HPCC controls. Published EtO reactions during extracorporeal procedures were reviewed with statistical analysis. Graphics and statistics were performed using commercial software.

RESULTS

Three autologous HPCC donors experienced EtO-type reactions within 15 min of initiating HPCC, for a 10-year incident rate of 0.08% per procedure and 0.18% per donor. All three reactions occurred using the Spectra Optia and IDL tubing set, for an Optia/IDL specific rate of 0.2% per procedure and 0.5% per donor. There was no correlation between EtO reactions, eosinophil counts, or saline prime dwell times. No patient had classic predisposing risk factors for EtO hypersensitivity. Two patients required medical intervention whereas the third responded by pausing the procedure and slowing the inlet rate.

CONCLUSION

EtO-type hypersensitivity reactions can be observed during HPCC, especially with the Optia IDL tubing set. EtO reactions may be missed due to their rarity and staff unfamiliarity with this clinical entity.

Effect of Sterilization Methods on Electrospun Scaffolds Produced from Blend of Polyurethane with Gelatin

Fibrous polyurethane-based scaffolds have proven to be promising materials for the tissue engineering of implanted medical devices. Sterilization of such materials and medical devices is an absolutely essential step toward their medical application. In the presented work, we studied the effects of two sterilization methods (ethylene oxide treatment and electron beam irradiation) on the fibrous scaffolds produced from a polyurethane-gelatin blend. Scaffold structure and properties were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared spectroscopy (FTIR), a stress-loading test, and a cell viability test with human fibroblasts. Treatment of fibrous polyurethane-based materials with ethylene oxide caused significant changes in their structure (formation of glued-like structures, increase in fiber diameter, and decrease in pore size) and mechanical properties (20% growth of the tensile strength, 30% decline of the maximal elongation). All sterilization procedures did not induce any cytotoxic effects or impede the biocompatibility of scaffolds. The obtained data determined electron beam irradiation to be a recommended sterilization method for electrospun medical devices made from polyurethane-gelatin blends.

cohort

BACKGROUND

Ethylene oxide (EtO) is a carcinogenic gas used in chemical production and to sterilize medical equipment that has been linked to risk of breast and lymphohematopoietic cancers in a small number of occupational studies. We investigated the relationship between environmental EtO exposure and risk of these cancers.

METHODS

Using the U.S. Environmental Protection Agency's Toxics Release Inventory, we estimated historical exposures for NIH-AARP Diet and Health Study participants enrolled in 1995-1996. We constructed two metrics at 3, 5, and 10 km: 1) distance between residences and EtO-emitting facilities, weighted by the proportion of time the home was downwind of each facility, and 2) distance-weighted, wind-direction-adjusted average airborne emissions index (AEI=∑[lbs EtO/km2]). We estimated risk (hazard ratio [HR], 95% confidence interval [95%CI]) of incident breast cancer (in situ and invasive) among postmenopausal women (N = 173,670) overall and by tumor estrogen receptor (ER) status and non-Hodgkin lymphoma (NHL) in the full cohort (N = 451,945).

RESULTS

We observed an increased risk of breast cancer associated with EtO-emitting facilities within 10 km (HR[≤10vs>10]=1.05, 95%CI = 1.00-1.10) that appeared stronger for in situ (HR[≤10vs>10]=1.13,95%CI = 1.00-1.27) than invasive (HR[≤10vs>10]=1.03,95%CI = 0.97-1.09) disease. Risk of breast cancer in situ was also increased in the top AEI quartiles, and associations weakened with larger distances (HRs[Q4vs0]=1.60,95%CI = 0.98-2.61; 1.28,95%CI = 0.92-1.79; 1.25,95%CI = 1.02-1.53 at 3, 5, and 10 km, respectively). No differences in breast cancer risk were observed by ER status. We found no clear pattern of increased NHL risk.

CONCLUSIONS

A novel potential association between EtO emissions and risk of in situ, but not invasive, breast cancer warrants additional evaluation.

Comparison of the methods of disinfection/sterilization of extracted human roots for research purposes

BACKGROUND

Extracted human teeth are used to simulate dental procedures and are essential for practical education and research studies.

OBJECTIVES

The aim of this study was to evaluate the efficacy of different sterilization methods for extracted human roots and to assess the effects of these methods on dentin microhardness.

MATERIAL AND METHODS

The crowns of 40 mandibular incisors were removed. The roots were sectioned at 10 mm and divided into 4 groups (n = 10 per group): G1 - no sterilization (control); G2 - microwave radiation (650 W, 5 min); G3 - ethylene oxide (288°C, 3 h); and G4 - autoclave (121°C, 15 min). The roots were immersed in brain heart infusion (BHI) and incubated at 37°C in variable oxygen atmospheres. After 14 days, the samples were assessed for turbidity. Three slices were obtained from each root, and indentations were made at 30, 60 and 120 μm from the root canal lumen. The microbiological data was analyzed with the Kruskal-Wallis test and Dunn's post-hoc test. Microhardness was evaluated by means of the twoway analysis of variance (ANOVA) and Tukey's test (p < 0.05).

RESULTS

The roots submitted to autoclaving were 100% sterile, which differed from the other methods (p < 0.05); the control specimens had 0% sterility. For microhardness, significant differences were found between the methods, particularly for the apical third (68.06 ±12.50) (p < 0.05).

CONCLUSIONS

Although all the evaluated techniques reduced dentin microhardness, autoclaving should be used as the most reliable method of sterilization of extracted dental roots.

Food Safety Governance and Guardianship: The Role of the Private Sector in Addressing the EU Ethylene Oxide Incident

Sesame seeds within the European Union (EU) are classified as foods not of animal origin. Two food safety issues associated with sesame seeds have emerged in recent years, i.e., Salmonella contamination and the presence of ethylene oxide. Fumigation with ethylene oxide to reduce Salmonella in seeds and spices is not approved in the EU, so its presence in sesame seeds from India was a sentinel incident sparking multiple trans-European product recalls between 2020-2021. Following an interpretivist approach, this study utilises academic and grey sources including data from the EU Rapid Alert System for Food and Feed (RASFF) database to inform a critical appraisal of current EU foods not of animal origin legislation and associated governance structures and surveillance programs. This is of particular importance as consumers are encouraged towards plant-based diets. This study shows the importance of collaborative governance utilizing data from company testing and audits as well as official regulatory controls to define the depth and breadth of a given incident in Europe. The development of reflexive governance supported by the newest technology (e.g., blockchain) might be of value in public-private models of food safety governance. This study contributes to the literature on the adoption of risk-based food safety regulation and the associated hybrid public-private models of food safety governance where both regulators and private organizations play a vital role in assuring public health.

Mass spectrometry of the soot left after ethylene oxide explosion answers some questions on the crash of Polish Air Force Flight 101

The Polish TU 154M plane, Polish Air Force Flight 101, had crashed near Smolensk on 10th of April 2010. The crash was investigated by The Interstate Aviation Committee, whose conclusions were questioned by a number of Polish scientists. The cause of the crash still appears to be incompletely documented and requires additional evidence. In this paper, investigations of a solid material eluted from a piece of cloth of one of the victims of the crash are described. High resolution mass spectrometry was applied to analyze the soot left after controlled ethylene oxide (EO) explosions, performed under different conditions. These included electric ignition of EO vapors in a large volume steel container, and explosions of glass tubes filled with liquid EO, stimulated by thermally initiated explosions of pentaerythritol tetranitrate (PETN). One of these explosions was conducted in the vessel used for the electric ignition of EO and the other in a hermetically locked, small volume container. It was shown that the soot comprises a set of C₂ H₄ O homopolymers and copolymers whose characteristic MS patterns are condition-dependent. The MS spectrum of the postcrash sample referred to above reveals a number of polymers that are also present in the soot obtained in PETN-initiated ethylene oxide explosions. It can be concluded that the piece of cloth was subjected to an EO explosion initiated by an explosion of energetic material, possibly PETN. Similar control experiments with ethylene glycol (EG) showed that the polymers identified in the investigated postcrash sample could not originate from exploding EG.

Cobalt Carbonyls Stabilized by N,P-Ligands: Synthesis, Structure, and Catalytic Property for Ethylene Oxide Hydroalkoxycarbonylation

Reactions of N,P-Ligands as Ph₂ P(o-NMe₂ C₆ H₄ ) (¹ L), 2,6-iPr₂ C₆ H₃ NHC(Ph)=NC₆ H₄ (o-PPh₂ ) (² L), and Ph₂ PN(R)PPh₂ (R=iPr (³ L), cyclo-C₆ H₁₁ (⁴ L), tBu (⁵ L), CH₂ C₄ H₇ O (⁶ L)) each with dicobalt octacarbonyl produced complexes [¹ LCo(CO)₃ ]₂ (1), [² LCo(CO)(μ-CO)₂ Co(CO)₃ ] (2), [³ LCo(CO)₃ ]⁺ [Co(CO)₄ ]^- (3), [³ LCo(CO)₂ ]₂ (4), [⁴ LCo(CO)₂ ]₂ (5), [⁵ LCo(CO)₂ ]⁺ [Co(CO)₄ ]^- (6), and [⁶ LCo(CO)₂ ]⁺ [Co(CO)₄ ]^- (7). Complexes 1-7 have all been structurally characterized by X-ray crystallography, IR and NMR spectroscopies, and elemental analysis. Catalytic tests on transformation of ethylene oxide (EO), CO and MeOH into methyl 3-hydroxypropionate (3-HMP) indicate that complexes 1-7 are active, where ion-pair complexes 3 and 6-7 behave more excellently (by achieving 88.4-93.6% 3-HMP yields) than the neutral species 1-2 and 4-5 (35.0-46.5% 3-HMP yields) when the reactions are all operated at 2 MPa CO pressure and 50 °C in MeOH solvent. Density functional theory (DFT) study by selecting 3 as a model suggests a cooperative catalytic reaction mechanism by [Co(CO)₄ ]^- and its counter cation [³ LCo(CO)₃ ]⁺ . The cobalt-homonuclear ion-pair catalyzed hydroalkoxycarbonylation of EO is present herein.

Characterization of the association between cigarette smoking intensity and urinary concentrations of 2-hydroxyethyl mercapturic acid among exclusive cigarette smokers in the National Health and Nutrition Examination Survey (NHANES) 2011-2016

BACKGROUND

2-Hydroxyethyl mercapturic acid (2HEMA, N-acetyl-S-(2-hydroxyethyl)-L-cysteine) is a urinary metabolite of several volatile organic compounds including acrylonitrile and ethylene oxide, which are found in cigarette smoke.

METHODS

We measured 2HEMA concentrations in urine specimens collected during the National Health and Nutrition Examination Survey (2011-2016) from eligible participants aged >12 years (N = 7,416). We developed two multiple linear regression models to characterize the association between cigarette smoking and 2HEMA concentrations wherein the dependent variable was 2HEMA concentrations among participants who exclusively smoked cigarettes at the time of specimen collection and the independent variables included sex, age, race/ethnicity, creatinine, diet, and either cigarettes smoked per day (CPD) or serum cotinine.

RESULTS

We detected 2HEMA in 85% of samples tested among exclusive cigarette smokers, and only 40% of specimens from non-smokers. When compared to exclusive cigarette smokers who smoked 1-9 CPD, smoking 10-19 CPD was associated with 36% higher 2HEMA (p < 0.0001) and smoking >19 CPD was associated with 61% higher 2HEMA (p < 0.0001). Additionally, 2HEMA was positively associated with serum cotinine.

CONCLUSIONS

This study demonstrates that cigarette smoking intensity is associated with higher urinary 2HEMA concentrations and is likely a major source of acrylonitrile and/or ethylene oxide exposure.

Application of Rapid Biological Indicators Coupled With Auto-Reader for the Quality Assurance of Surgical Instruments After Sterilization at a Cardiac Hospital in Bangladesh

Background Sterilization failure is one of the main reasons for surgical site infections (SSIs). The biological indicator (BI) test is the most reliable test to check sterilization efficiencies. But 48 hours BI test result makes the monitoring process time-consuming. Rapid BI testing can be time demanding in this regard. Therefore, the objective is to determine the importance of rapid BI monitoring for the quality assurance of sterile surgical instruments. Methods This study was conducted in the Labaid Cardiac Hospital, Bangladesh from April 1, 2021, to July 8, 2021. A total of 100 steam and 100 ethylene oxide (EO) rapid BIs and an auto reader incubator were used to conduct this research. Quick BI of steam and EO were used once per day and tested by the auto reader. Later, all the tested BIs were incubated for 48 hours by a conventional incubator to confirm the auto reader's rapid BI test results. Result All the EO BI results were found negative, but the BI was found positive twice in steam sterilization. Surgical items of those two loads were re-sterilized. Again, after checking the BI result, the items were released. All BIs except positive steam rapid BIs were found with no growth after 48 hours of incubation for cross-checking of auto reader results. In positive rapid BI of steam, growth was found after 48 hours of incubation. Conclusion When sterilization failure occurred, process recall could not be possible at that time if rapid BI tests were not performed. So, integration of a rapid BI test with an auto reader can save the patient from critical SSI.

Influence of sterilization conditions on sulfate-functionalized polyGGE

Sulfated biomolecules are known to influence numerous biological processes in all living organisms. Particularly, they contribute to prevent and inhibit the hypercoagulation condition. The failure of polymeric implants and blood contacting devices is often related to hypercoagulation and microbial contamination. Here, bioactive sulfated biomacromolecules are mimicked by sulfation of poly(glycerol glycidyl ether) (polyGGE) films. Autoclaving, gamma-ray irradiation and ethylene oxide (EtO) gas sterilization techniques were applied to functionalized materials. The sulfate group density and hydrophilicity of sulfated polymers were decreased while chain mobility and thermal degradation were enhanced post autoclaving when compared to those after EtO sterilization. These results suggest that a quality control after sterilization is mandatory to ensure the amount and functionality of functionalized groups are retained.

Hybrid Copolymerization of Ethylene Oxide and tert-Butyl Methacrylate with Organocatalyst

Hybrid copolymerization of structurally different, reactivity and mechanism distinct monomers (e.g., cyclic and vinyl type monomers) is of great interest and challenge for both academic research and practical application. Herein, ethylene oxide-co-tert-butyl methacrylate-co-poly(ethylene glycol) benzyl methacrylate (EO-co-BMA-co-bPEO), a statistical copolymer was synthesized via hybrid copolymerization of EO and BMA using an uncharged, non-nucleophilic organobase t-BuP₄ as the catalyst. Detailed characterizations indicate that hybrid copolymerization of ethylene oxide and vinyl monomer forms a statistical copolymer concurrently with the transesterification of tert-butyl group and oligomer PEO anions. The application of the copolymer as all solid lithium-ion battery polymer electrolyte was investigated by detecting the ionic conductivity (σ) with electrical impedance spectrum measurement.

How to Sterilize Polylactic Acid Based Medical Devices?

How sterilization techniques accurately affect the properties of biopolymers continues to be an issue of discussion in the field of biomedical engineering, particularly now with the development of 3D-printed devices. One of the most widely used biopolymers in the manufacture of biomedical devices is the polylactic acid (PLA). Despite the large number of studies found in the literature on PLA devices, relatively few papers focus on the effects of sterilization treatments on its properties. It is well documented in the literature that conventional sterilization techniques, such as heat, gamma irradiation and ethylene oxide, can induced damages, alterations or toxic products release, due to the thermal and hydrolytical sensitivity of PLA. The purposes of this paper are, therefore, to review the published data on the most common techniques used to sterilize PLA medical devices and to analyse how they are affecting their physicochemical and biocompatible properties. Emerging and alternative sterilization methods for sensitive biomaterials are also presented.

Sterilization of Drug-Loaded Composite Coatings for Implantable Glucose Biosensors

BACKGROUND

An anti-inflammatory drug-loaded composite coating (dexamethasone-loaded poly (lactic-co-glycolic acid) [PLGA] microspheres/polyvinyl alcohol [PVA] hydrogel) was previously developed to counter the foreign body reaction to a fully implantable continuous glucose monitoring biosensor. The long-term sensor functionality was ensured in the presence of the drug-loaded composite coating thus facilitating better diabetes control and management. In order to advance such a drug-device combination product toward clinical testing, addressing sterilization remains a key step due to the heterogeneity of the product components. The main objective of this research was to investigate the effect of two terminal sterilization techniques: gamma radiation and ethylene oxide (EO) on the stability of the anti-inflammatory coatings as well as retention of the glucose sensing ability of the implantable sensor.

METHOD

The composite coatings, their individual components, and the glucose-sensing elements of the biosensor were subjected to low-temperature gamma radiation and EO cycles. Detailed characterization was conducted on all components before and after sterilization.

RESULTS

Exposure to gamma radiation affected dexamethasone crystallinity and glucose response linearity of the sensing element, whereas physical aging of microspheres in composite coatings was observed poststerilization with EO. Despite these effects, dexamethasone drug release from coatings was not significantly affected by either technique.

CONCLUSION

The research findings indicate that both sterilization techniques are feasible for the sterilization of the dexamethasone-loaded PLGA microspheres/PVA hydrogel composite coatings, while EO was preferred for the sterilization of the glucose-sensing element of the biosensor.

Populations Residing Near Sterilization and Other Industrial Facilities: Context Based on Endogenous and Total Equivalent Concentration Exposures

Given ubiquitous human exposure to ethylene oxide (EO), regardless of occupation or geography, the current risk-specific concentrations (RSCs: 0.0001-0.01 ppb) from the U.S. Environmental Protection Agency (EPA) cancer risk assessment for EO are not useful metrics for managing EO exposures to the general U.S. population. The magnitude of the RSCs for EO are so low, relative to typical endogenous equivalent metabolic concentrations (1.1-5.5 ppb) that contribute ~93% of total exposure, that the RSCs provide little utility in identifying excess environmental exposures that might increase cancer risk. EO monitoring data collected in the vicinity of eight EO-emitting facilities and corresponding background locations were used to characterize potential excess exogenous concentrations. Both 50th and 90th percentile exogenous exposure concentrations were combined with the 50th percentile endogenous exposure concentration for the nonsmoking population, and then compared to percentiles of total equivalent concentration for this population. No potential total exposure concentration for these local populations exceeded the normal total equivalent concentration 95th percentile, indicating that excess facility-related exposures are unlikely to require additional management to protect public health.

Toward Replacing Ethylene Oxide in a Sustainable World: Glycolaldehyde as a Bio-Based C2 Platform Molecule

Fossil-based platform molecules such as ethylene and ethylene oxide currently serve as the primary feedstock for the C₂ -based chemical industry. However, in the search for a more sustainable chemical industry, fossil-based resources may preferentially be replaced by renewable alternatives, provided there is realistic economic feasibility. This Review compares and critically discusses several production routes toward bio-based structural analogues of ethylene oxide and the required adaptations for their implementation in state-of-the-art C₂ -based chemical processes. For example, glycolaldehyde, a structural analogue obtainable from carbohydrates by atom-economic retro-aldol reactions, may replace ethylene oxide's leading role. This alternative chemical route may not only allow the carbon footprint of conventional chemicals production to be lowered, but the introduction of a bio-based pathway may also contribute to safer production processes. Where possible, challenges, drawbacks, and prospects are highlighted.

Levels of Ethylene Oxide Biomarker in an Exposed Residential Community

The purpose of this study was to examine whether there is a difference in ethylene oxide (EtO) biomarker levels based on residential proximity to facilities emitting EtO, a carcinogen. We recruited residents living near two EtO-emitting facilities and administered a questionnaire on items such as address and length of residency, smoking habits, occupational exposures to EtO, and demographics. We also collected venous blood samples to measure an EtO biomarker, hemoglobin adduct N-2-hydroxyethyl-valine (HbEO), and cotinine, a metabolite of nicotine. Questionnaires and blood samples were collected from 93 participants. The overall geometric HbEO adduct level was 35.0 pmol/gmHb and for nonsmokers it was 29.7 pmol/gmHb. Mean HbEO adduct levels were not significantly associated with sex, age, race, BMI, or education level. HbEO adduct levels for nonsmoking participants who lived in a neighborhood approximately 0.8 km from one of the facilities were significantly higher compared to persons living farther away (p < 0.001). These results suggest that facilities that emit EtO may put nearby communities at risk of cancer and other associated health outcomes.

Enabling Oxygen-Sulfur Exchange Reaction to Produce Semicrystalline Copolymers from Carbon Disulfide and Ethylene Oxide

This work describes the first example of semicrystalline poly(thiocarbonate)s from carbon disulfide (CS₂ ) and ethylene oxide (EO), two mass producible low-cost monomers. Lewis acid/base pairs (LPs) exhibit high activity (EO conversion up to >99%, 8 h) in catalyzing the copolymerization under low Lewis pair/monomer ratio of 1:1500. Oxygen-sulfur exchange reaction (O-S ER) during the copolymerization of CS₂ and EO, the generation and mutual copolymerization with COS, CO₂ , and episulfide, is harnessed to introduce crystallizable segments [SC(O)O and SC(S)S] in the copolymer. The type of Lewis base is found to have a great impact on the chain microstructure and the crystalline properties. The formed copolymers with melting point from 117.7 to 245.3 °C are obtained. The maximum crystallinity is estimated to be 78% based on the powder wide-angle X-ray diffraction pattern. This work provides a general method to prepare semicrystalline sulfur-containing polymers.

[Source Analysis of Ethylene Oxide Sterilization Residues in Medical Devices]

At present, the most commonly used sterilization method for medical devices is ethylene oxide sterilization. The residue after sterilization is closely related to the health of the people who contacted with the medical devices. The study team analyzed the possible residues of medical devices after sterilization with ethyleneoxide. It is suggested that ethylene oxide, 2-chloroethanol and ethylene glycol should be evaluated comprehensively through the analysis of factors such as production links of medical devices, production process of ethylene oxide, sterilization process, sterilization environment and detection method.

Ethylene Oxide Exposure Attribution and Emissions Quantification Based on Ambient Air Measurements near a Sterilization Facility

Ethylene oxide (EtO) is a known carcinogen and mutagen associated with increased incidence of breast and blood cancers. The largest medical sterilization facility in Michigan had been assessed by the U.S. Environmental Protection Agency as imposing an additional cancer risk greater than one in one thousand in nearby neighborhoods. This prompted the Michigan Department of Environmental Quality (now referred to as the Department of Environment, Great Lakes, and Energy) to conduct an air quality modeling study of the ambient EtO impacts of the sterilization facility, followed by 24 h Summa canister sampling and TO-15 analysis in two phases. Inverse modeling of the measured 24 h EtO concentrations during the second phase yielded estimates of 594 lbs/year for the facility's total emissions of EtO and 0.247 µg/m³ for the urban background concentration. The inverse-modeled emissions are similar to reported emissions by the facility operator based on indoor air measurements and simple mass balance assumptions, while the inferred background concentration agrees with estimates from other field investigations. The estimated peak 24 h exposure to EtO caused by the sterilization facility in nearby neighborhoods was 1.83 μg/m³ above the background level, corresponding to an additional cancer risk of approximately one in one hundred, if assumed to represent annual mean exposure.

Ca-Ag compounds in ethylene epoxidation reaction

The ethylene epoxidation is a challenging catalytic process, and development of active and selective catalyst requires profound understanding of its chemical behaviour under reaction conditions. The systematic study on intermetallic compounds in the Ca-Ag system under ethylene epoxidation conditions clearly shows that the character of the oxidation processes on the surface originates from the atomic interactions in the pristine compound. The Ag-rich compounds Ca₂Ag₇ and CaAg₂ undergo oxidation towards fcc Ag and a complex Ca-based support, whereas equiatomic CaAg and the Ca-rich compounds Ca₅Ag₃ and Ca₃Ag in bulk remain stable under harsh ethylene epoxidation conditions. For the latter presence of water vapour in the gas stream leads to noticeable corrosion. Combining the experimental results with the chemical bonding analysis and first-principles calculations, the relationships among the chemical nature of the compounds, their reactivity and catalytic performance towards epoxidation of ethylene are investigated.

Sterilization Workers in the National Institute of Occupational Safety and Health (NIOSH) Study Cohort

The 2016 U.S. Environmental Protection Agency (EPA) Integrated Risk Information System (IRIS) assessment for ethylene oxide (EO) estimated a 10⁻⁶ increased inhalation cancer risk of 0.1 parts per trillion, based on National Institute of Occupational Safety and Health (NIOSH) epidemiology studies of sterilization facility workers exposed to EO between 1938 and 1986. The worker exposure estimates were based on a NIOSH statistical regression (NSR) model “validated” with EO levels measured after 1978. Between 1938 and 1978, when EO data was unavailable, the NSR model predicts exposures lowest in 1938 increasing to peak levels in 1978. That increasing EO concentration trend arose, in part, because engineering/industrial-hygiene (E/IH) factors associated with evolving EO-sterilization equipment and operations before 1978 were not properly considered in the NSR model. To test the NSR model trend prediction, a new E/IH-based model was developed using historical data on EO kill concentrations, EO residue levels in sterilized materials, post-wash EO concentrations in a sterilization chamber, and information on facility characteristics and sterilizer operator practices from operators familiar with pre-1978 industry conditions. The E/IH 90th percentile of 8 h time-weighted average EO exposures (C₉₀) for highly exposed sterilizer operators was calibrated to match 1978 C₉₀ values from the NSR model. E/IH model C₉₀ exposures were estimated to decrease over time from levels 16 and were four-fold greater than NSR-estimated exposures for workers during 1938–1954 and 1955–1964. This E/IH modeled trend is opposite to that of NSR model predictions of exposures before 1978, suggesting that EPA’s exclusive reliance on the NIOSH cohort to estimate EO cancer risk should be re-examined.

A Methodologic Approach for the Selection of Bio-Resorbable Polymers in the Development of Medical Devices: The Case of Poly(l-lactide-co-ε-caprolactone)

In the last decades bioresorbable and biodegradable polymers have gained a very good reputation both in research and in industry thanks to their unique characteristics. They are able to ensure high performance and biocompatibility, at the same time avoiding post-healing surgical interventions for device removal. In the medical device industry, it is widely known that product formulation and manufacturing need to follow specific procedures in order to ensure both the proper mechanical properties and desired degradation profile. Moreover, the sterilization method is crucial and its impact on physical properties is generally underestimated. In this work we focused our attention on the effect of different terminal sterilization methods on two commercially available poly(l-lactide-co-ε-caprolactone) with equivalent chemical composition (70% PLA and 30% PCL) and relatively similar initial molecular weights, but different chain arrangements and crystallinity. Results obtained show that crystallinity plays a key role in helping preserve the narrow distribution of chains and, as a consequence, defined physical properties. These statements can be used as guidelines for a better choice of the most adequate biodegradable polymers in the production of resorbable medical devices.

Carcinogenicity of ethylene oxide: key findings and scientific issues

In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) completed an evaluation of the inhalation carcinogenicity of ethylene oxide (EtO) in December 2016. This article reviews key findings and scientific issues regarding the carcinogenicity of EtO in EPA's Carcinogenicity Assessment. EPA's assessment critically reviewed and characterized epidemiologic, laboratory animal, and mechanistic studies pertaining to the human carcinogenicity of EtO, and addressed some key scientific issues such as the analysis of mechanistic data as part of the cancer hazard evaluation and to inform the quantitative risk assessment. The weight of evidence from the epidemiologic, laboratory animal, and mechanistic studies supports a conclusion that EtO is carcinogenic in humans, with the strongest human evidence linking EtO exposure to lymphoid and breast cancers. Analyses of the mechanistic data establish a key role for genotoxicity and mutagenicity in EtO-induced carcinogenicity and reveal little evidence supporting other mode-of-action hypotheses. In conclusion, EtO was found to be carcinogenic to humans by inhalation, posing a potential human health hazard for lymphoid and breast cancers.

Solvent or thermal extraction of ethylene oxide from polymeric materials: Medical device considerations

Ethylene oxide (EO) gas is commonly used to sterilize medical devices. Bioavailable residual EO, however, presents a significant toxicity risk to patients. Residual EO is assessed using international standards describing extraction conditions for different medical device applications. We examine a series of polymers and explore different extraction conditions to determine residual EO. Materials were sterilized with EO and exhaustively extracted in water, in one of three organic solvents, or in air using thermal desorption. The EO exhaustively extracted varies significantly and is dictated by two factors: the EO that permeates the material during sterilization; and the effectiveness of the extraction protocol in flushing residual EO from the material. Extracted EO is maximized by a close matches between Hildebrand solubility parameters δ_polymer , δ_EO , and δ_solvent . There remain complexities to resolve, however, because maximized EO uptake and detection are accompanied by great variability. These observations may inform protocols for material selection, sterilization, and EO extraction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2455-2463, 2018.

Ethylene oxide as an occupational contact allergen - an underestimated problem?

Background: Ethylene oxide (EtO) is a volatile epoxy compound which is used to sterilize medical devices. EtO may cause irritant contact dermatitis, but only few cases of allergic contact dermatitis have been reported yet. Objectives: About 20 employees of a department for surgery developed eczematous skin reactions at the contact areas to wrist bands of surgical gowns which had been sterilized with EtO. Patch tests were performed to exclude contact allergy. Methods: Due to the volatility of EtO, patch tests were done with epichlorohydrin (0.1% pet., 1% pet.) which is an epoxy compound chemically related to EtO. Results: 7/8 patients and 4 healthy control persons showed non-allergic irritant reactions to 1.0% epichlorohydrin. 1.0% epichlorohydrin may have induced an iatrogenic sensitization in one of the control persons. None of the control persons reacted to 0.1% epichlorohydrin. Allergic contact dermatitis to EtO and a cross sensitization to epichlorohydrin was diagnosed in a nurse who showed an allergic crescendo patch test reaction to 0.1% epichlorohydrin. Conclusions: EtO can act as an occupational contact allergen in health personnel, a problem that may have been underestimated in the past due to methodological difficulties in patch testing. When allergic contact dermatitis to EtO is suspected, a patch test to 0.1% epichlorohydrin should be performed.

The Effect of Sterilization Methods of Endoscopic Instruments on the Body: A Study on Rat Model

PURPOSE

Laparoscopy is widely used in many surgical areas for diagnosis and treatment. The need for sterilization of reusable instruments is an important issue. Ensuring patient safety, preventing infection, and protecting the functionality of the instruments are the most important points to be considered. We aimed to investigate two sterilization methods and their effects generated by their distribution into intra-abdominal tissues during insufflation.

MATERIALS AND METHODS

21 rats were used in the study. The Control Group (Group 1) received anesthesia for 1 hour; Group 2 (Glutaraldehyde (GA)-Pneumoperitoneum Group) received anesthesia for 1 hour; Group 3 (Ethylene Oxide (EO)-Pneumoperitoneum Group) received anesthesia for 1 hour. After 24 hours, the animals were sacrificed, and the kidneys and omentum of the animals were analyzed in a histopathological manner. Blood samples were analyzed at preoperative 24th hour and at postoperative 24th hour.

RESULTS

There was a statistically significant difference in omentum, endothelium, and glomerular scores between the groups (p < 0.001 for all groups). Endothelial and glomerular scores were different at a statistically significant level in the EO and GA groups compared to the Control Group. The total score was higher at a statistically significant level in the EO and GA groups compared to the Control Group (p < 0.001 for both groups).

CONCLUSION

It was determined in our study that sterilization methods such as EO and GA cause damage in intra-abdominal tissues. In the light of these results, we consider that the most ideal laparoscopic surgery set is the single-use laparoscopy set. However, this does not seem possible especially in developing countries in practice.

Processes to Preserve Spice and Herb Quality and Sensory Integrity During Pathogen Inactivation

Selected processing methods, demonstrated to be effective at reducing Salmonella, were assessed to determine if spice and herb quality was affected. Black peppercorn, cumin seed, oregano, and onion powder were irradiated to a target dose of 8 kGy. Two additional processes were examined for whole black peppercorns and cumin seeds: ethylene oxide (EtO) fumigation and vacuum assisted-steam (82.22 °C, 7.5 psia). Treated and untreated spices/herbs were compared (visual, odor) using sensory similarity testing protocols (α = 0.20; β = 0.05; proportion of discriminators: 20%) to determine if processing altered sensory quality. Analytical assessment of quality (color, water activity, and volatile chemistry) was completed. Irradiation did not alter visual or odor sensory quality of black peppercorn, cumin seed, or oregano but created differences in onion powder, which was lighter (higher L^* ) and more red (higher a^* ) in color, and resulted in nearly complete loss of measured volatile compounds. EtO processing did not create detectable odor or appearance differences in black peppercorn; however visual and odor sensory quality differences, supported by changes in color (higher b^* ; lower L^* ) and increased concentrations of most volatiles, were detected for cumin seeds. Steam processing of black peppercorn resulted in perceptible odor differences, supported by increased concentration of monoterpene volatiles and loss of all sesquiterpenes; only visual differences were noted for cumin seed. An important step in process validation is the verification that no effect is detectable from a sensory perspective.

A sterilizable, biocompatible, tropoelastin surface coating immobilized by energetic ion activation

Biomimetic materials which integrate with surrounding tissues and regulate new tissue formation are attractive for tissue engineering and regenerative medicine. Plasma immersion ion-implanted (PIII) polyethersulfone (PES) provides an excellent platform for the irreversible immobilization of bioactive proteins and peptides. PIII treatment significantly improves PES wettability and results in the formation of acidic groups on the PES surface, with the highest concentration observed at 40-80 s of PIII treatment. The elastomeric protein tropoelastin can be stably adhered to PIII-treated PES in a cell-interactive conformation by tailoring the pH and salt levels of the protein-surface association conditions. Tropoelastin-coated PIII-treated PES surfaces are resistant to molecular fouling, and actively promote high levels of fibroblast adhesion and proliferation while maintaining cell morphology. Tropoelastin, unlike other extracellular matrix proteins such as fibronectin, uniquely retains full bioactivity even after medical-grade ethylene oxide sterilization. This dual approach of PIII treatment and tropoelastin cloaking allows for the stable, robust functionalization of clinically used polymer materials for directed cellular interactions.

A Nanoarchitecture Based on Silver and Copper Oxide with an Exceptional Response in the Chlorine-Promoted Epoxidation of Ethylene

The selective oxidation of ethylene to ethylene epoxide is highly challenging as a result of competing reaction pathways leading to the deep oxidation of both ethylene and ethylene oxide. Herein we present a novel catalyst based on silver and copper oxide with an excellent response in the selective oxidation pathway towards ethylene epoxide. The catalyst is composed of different silver nanostructures dispersed on a tubular copper oxide matrix. This type of hybrid nanoarchitecture seems to facilitate the accommodation of chlorine promoters, leading to high yields at low reaction temperatures. The stability after the addition of chlorine promoters implies a substantial improvement over the industrial practice: a single pretreatment step at ambient pressure suffices in contrast with the common practice of continuously feeding organochlorinated precursors during the reaction.

Hospitals

OBJECTIVE

Evaluate precautionary practices and extent of use of ethylene oxide (EtO) and hydrogen peroxide gas plasma (HPGP) sterilization systems, including use of single chamber EtO units.

DESIGN

Modular, web-based survey.

PARTICIPANTS

Members of professional practice organizations who reported using EtO or HPGP in the past week to sterilize medical instruments and supplies. Participating organizations invited members via email which included a hyperlink to the survey.

METHODS

Descriptive analyses were conducted including simple frequencies and prevalences.

RESULTS

A total of 428 respondents completed the module on chemical sterilants. Because most respondents worked in hospitals (87%, n=373) analysis focused on these workers. Most used HPGP sterilizers (84%, n=373), 38% used EtO sterilizers, with 22% using both. Nearly all respondents using EtO operated single chamber units (94%, n=120); most of them reported that the units employed single use cartridges (83%, n=115). Examples of where engineering and administrative controls were lacking for EtO include: operational local exhaust ventilation (7%; n=114); continuous air monitoring (6%; n=113); safe handling training (6%; n=142); and standard operating procedures (4%; n=142). Examples of practices which may increase HPGP exposure risk included lack of standard operating procedures (9%; n=311) and safe handling training (8%; n=312).

CONCLUSIONS

Use of precautionary practices was good but not universal. EtO use appears to have diminished in favor of HPGP which affords higher throughput and minimal regulatory constraints. Separate EtO sterilization and aeration units were still being used nearly one year after U.S. EPA prohibited their use.

Accidental exposure to gas emissions from transit goods treated for pest control

BACKGROUND

International phytosanitary standards ISPM 15 require (since 2007) fumigation or heat treatment for shipping and storage. Those dealing with fumigated freight might be accidentally exposed. In this paper we report a series of three accidents of six storage room workers in a medium sized company regularly importing electronic production parts from abroad.

METHODS

Patients (n=6, aged from 32-54 yrs.) and control group (n=30, mean 40 yrs.) donated blood and urine samples. The fumigants: ethylene oxide, methyl bromide, chloropicrin, ethylene dichloride, other halo-alkanes and solvents were analyzed by headspace gas chromatography/mass spectrometry (GCMS). For the quantitation of long term exposure/s, macromolecular reaction products (hemoglobin adducts) were used (with GCMS) as molecular dosimeter; additionally 8-OHdG and circulating mtDNA (cmtDNA) were analyzed as nonspecific biological effect markers.

RESULTS

The hemoglobin adducts N-methyl valine (MEV) and N-(2-hydroxy ethyl) valine (HEV) were elevated after exposure to the alkylating chemicals methyl bromide and ethylene oxide. Under the consideration of known elimination kinetics and the individual smoking status (biomonitored with nicotine metabolite cotinine and tobacco specific hemoglobin adduct: N-(2 cyan ethyl) valines, CEV), the data allow theoretical extrapolation to the initial protein adduct concentrations at the time of the accident (the MEV/CEV levels were from 1,616 pmol/g globin to 1,880 pmol/g globin and HEV/CEV levels from 1,407 pmol/g globin to 5,049 pmol/g globin, and correlated with inhaled 0.4-1.5 ppm ethylene oxide. These integrated, extrapolated internal doses, calculated on the basis of biological exposure equivalents, confirmed the clinical diagnosis for three patients, showing severe intoxication symptoms. Both, cmtDNA and 8-OHdG, as non-specific biomarkers of toxic effects, were elevated in four patients.

CONCLUSION

The cases reported here, stress the importance of a suitable risk assessment and control measures. We put emphasis on the necessity of human biomonitoring guidelines and the urgency for the relevant limit values.

Application of a modified gaseous exposure system to the in vitro toxicological assessment of tobacco smoke toxicants

Tobacco smoke is a complex mixture of over 6,000 individual chemical constituents. Approximately 150 of these have been identified as 'tobacco smoke toxicants' due to their known toxicological effects. A number of these toxicants are present in the gaseous phase of tobacco smoke. This presents a technical challenge when assessing the toxicological effects of these chemicals in vitro. We have adapted a commercially available tobacco smoke exposure system to enable the assessment of the contribution of individual smoke toxicants to the overall toxicological effects of whole mainstream cigarette smoke (WS). Here we present a description of the exposure system and the methodology used. We use the example of a gaseous tobacco smoke toxicant, ethylene oxide (EtO), a Group 1 IARC carcinogen and known mutagen, to illustrate how this methodology can be applied to the assessment of genotoxicity of gaseous chemicals in the context of WS. In the present study we found that EtO was positive in Salmonella typhimurium strain YG1042, a strain that is sensitive to tobacco smoke. However, EtO did not increase the mutagenicity of the WS mixture when it was added at greatly higher concentrations than those found typically in WS. The findings presented here demonstrate the suitability of this exposure system for the assessment of the mutagenic potential of gases in vitro. Whilst we have focused on tobacco smoke toxicants, this system has broad application potential in studying the biological effects of exposure to a wide range of gaseous compounds that are present within complex aerosol mixtures.

Ethylene oxide in blood of ethylene-exposed B6C3F1 mice, Fischer 344 rats, and humans

The gaseous olefin ethylene (ET) is metabolized in mammals to the carcinogenic epoxide ethylene oxide (EO). Although ET is the largest volume organic chemical worldwide, the EO burden in ET-exposed humans is still uncertain, and only limited data are available on the EO burden in ET-exposed rodents. Therefore, EO was quantified in blood of mice, rats, or 4 volunteers that were exposed once to constant atmospheric ET concentrations of between 1 and 10 000 ppm (rodents) or 5 and 50 ppm (humans). Both the compounds were determined by gas chromatography. At ET concentrations of between 1 and 10 000 ppm, areas under the concentration-time curves of EO in blood (µmol × h/l) ranged from 0.039 to 3.62 in mice and from 0.086 to 11.6 in rats. At ET concentrations ≤ 30 ppm, EO concentrations in blood were 8.7-fold higher in rats and 3.9-fold higher in mice than that in the volunteer with the highest EO burdens. Based on measured EO concentrations, levels of EO adducts to hemoglobin and lymphocyte DNA were calculated for diverse ET concentrations and compared with published adduct levels. For given ET exposure concentrations, there were good agreements between calculated and measured levels of adducts to hemoglobin in rats and humans and to DNA in rats and mice. Reported hemoglobin adduct levels in mice were higher than calculated ones. Furthermore, information is given on species-specific background adduct levels. In summary, the study provides most relevant data for an improved assessment of the human health risk from exposure to ET.

Susceptibility of lung epithelial cells to alkylating genotoxic insult

Alkylation is one of the most common types of DNA damage that can lead to mutations and cancer. Lung is the primary target organ of airborne alkylators such as ethylene oxide (EO). However, the ability of EO to cause lung cancer has not been clearly demonstrated yet. The aim of this study was to investigate the susceptibility of lung cells to alkylating DNA insult by detecting EO-mediated DNA damage with the alkaline comet assay in human lung epithelial cells, peripheral blood lymphocytes, and keratinocytes. The susceptibility of these cell types toward the alkylating insult induced by EO was compared against the oxidative DNA insult induced by hydrogen peroxide (H2 O2 ). Due to the volatility of EO, its active concentrations were monitored by gas chromatography during exposure and were found to decrease significantly in a time-dependent manner. EO induced a statistically significant genotoxic effect at the lowest concentration used (16.4 µM) in lung epithelial cells and in lymphocytes, while in keratinocytes, a genotoxic effect was not detected until 55.5 µM EO. However, lung epithelial cells demonstrated increased resistance to oxidative insult. In fact, oxidative DNA damage detectable by endonuclease treatment was minimal in lung cells compared with the other cell types. These results suggest an increased sensitivity of lung epithelial cells toward the alkylating effects of EO, which was not observed for oxidative DNA damage. Our findings point out the importance of DNA alkylation and the possible role of EO on the induction of lung cancer.

Initial experience with the use of foetal/neonatal bovine acellular dermal collagen matrix (SurgiMend™) for tissue-expander breast reconstruction

BACKGROUND

Acellular dermal matrix (ADM) is commonly used in staged breast reconstruction using tissue expanders (TEs). The literature on human ADM has reported variable outcomes, and there is a paucity of data for xenogenic sources of ADM. The aim of this study is to evaluate the early complications, risk factors and outcomes using SurgiMend™ in staged breast reconstruction.

METHODS

An Institutional Review Board (IRB)-approved, retrospective analysis of a single surgeon's experience was performed. From August 2009 to May 2011, 65 patients underwent staged breast reconstruction using 95 sheets of SurgiMend™. The nominal TE fill volume was 383 ± 83 cc (range 250-550), mean intra-operative fill volume was 148 ± 86 cc (range 0-350) and mean final fill volume was 413 ± 176 cc (range 100-800). The mean clinic follow-up time was 16.9 ± 8.7 months; mean age was 50.9 ± 11.7 years; and average body mass index (BMI) was 26.0 ± 5.5 kg m(-2). Correlation with risk factors and clinical outcomes were analysed.

RESULTS

The incidences of postoperative complications were: haematoma 3.2%, seroma 7.5% and re-operation due to infection 2.1%. Age, diabetes mellitus, and hypertension had a significant correlation with an increased overall complication rate. With respect to early complications, such as infection requiring re-operation, diabetes demonstrated a trend with an odds ratio of 11.69.

CONCLUSION

This study demonstrates that the use of SurgiMend™ is associated with low early complication rates and is well tolerated in staged breast reconstruction.