Comparative study of the leachability of di(2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate from haemodialysis tubing

Effects of Behavioral, Clinical, and Policy Interventions in Reducing Human Exposure to Bisphenols and Phthalates: A Scoping Review

BACKGROUND

There is growing interest in evidence-based interventions, programs, and policies to mitigate exposures to bisphenols and phthalates and in using implementation science frameworks to evaluate hypotheses regarding the importance of specific approaches to individual or household behavior change or institutions adopting interventions.

OBJECTIVES

This scoping review aimed to identify, categorize, and summarize the effects of behavioral, clinical, and policy interventions focused on exposure to the most widely used and studied bisphenols [bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF)] and phthalates with an implementation science lens.

METHODS

A comprehensive search of all individual behavior, clinical, and policy interventions to reduce exposure to bisphenols and phthalates was conducted using PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Google Scholar. We included studies published between January 2000 and November 2022. Two reviewers screened references in CADIMA, then extracted data (population characteristics, intervention design, chemicals assessed, and outcomes) for studies meeting inclusion criteria for the present review.

RESULTS

A total of 58 interventions met the inclusion criteria. We classified interventions as dietary (n = 27 ), clinical (n = 13 ), policy (n = 14 ), and those falling outside of these three categories as "other" (n = 4 ). Most interventions (81%, 47/58) demonstrated a decrease in exposure to bisphenols and/or phthalates, with policy level interventions having the largest magnitude of effect.

DISCUSSION

Studies evaluating policy interventions that targeted the reduction of phthalates and BPA in goods and packaging showed widespread, long-term impact on decreasing exposure to bisphenols and phthalates. Clinical interventions removing bisphenol and phthalate materials from medical devices and equipment showed overall reductions in exposure biomarkers. Dietary interventions tended to lower exposure with the greatest magnitude of effect in trials where fresh foods were provided to participants. The lower exposure reductions observed in pragmatic nutrition education trials and the lack of diversity (sociodemographic backgrounds) present limitations for generalizability to all populations. https://doi.org/10.1289/EHP11760.

Endocrine disruptors in dialysis therapies: A literature review

Endocrine disrupting chemicals (EDCs) were defined as "an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects". These compounds are mainly eliminated by the renal route. However, patients with end-stage kidney disease treated by dialysis (ESKDD) can no longer eliminate these EDCs efficiently. Furthermore, EDCs exposure could occur via leaching from medical devices used in dialysis therapy. As a result, ESKDD patients are overexposed to EDCs. The aims of this study were to summarize EDCs exposure of ESKDD patients and to evaluate the factors at the origin of this exposure. To handle these objectives, we performed a literature review. An electronic search on PubMed, Embase and Web of science databases was performed. Twenty-six studies were finally included. The EDCs reported in these studies were Bisphenol A (BPA), Bisphenol S (BPS), Bisphenol B (BPB), Nonylphenol, Di(2-ethylhexyl) phthalate (DEHP), Di-n-butyl phthalate (DBP), and Butylbenzyl phthalate (BBP). Regarding the environment of dialysis patients, BPA, BPB, BPS, DEHP, DBP and nonylphenol have been found. Environmental exposure affects EDCs blood levels in ESKDD patients who are overexposed to BPA, BPS, BPB and DEHP. For ESKDD patients, dialyzers with housing in polycarbonate and fibers in polysulfone seem to overexpose them to BPA. Regarding dialysis therapy, peritoneal dialysis seems to decrease patient exposure vs hemodialysis therapy, and hemodiafiltration therapy seems to reduce this exposure vs hemodialysis therapy. Regarding DEHP, levels tend to increase during dialysis and when DEHP plasticizer is used in PVC devices. Finally, in the European Union a regulation on medical devices was adopted on 5 April 2017 and has been applied recently. This regulation will regulate EDCs in medical devices and thereby contribute to reconsideration of their conceptions and, finally, to reduction of ESKDD patients' exposure.

Medical devices used in NICU: The main source of plasticisers' exposure of newborns

Phthalates and other plasticisers are extensively used in medical devices (MD) from which they can leach out and lead to potential multiple problems for the patients. This exposure is a major issue because it is associated with reproductive and neurodevelopment disorders. The Neonatal Intensive Care Units (NICU) population is at high risk due to the daily intensive medical interventions, the reduced ability of newborns to remove these contaminants and their higher sensitivity to endocrine disruptors. We conducted a multicentric biomonitoring study to assess and compare the urinary levels of DEHP (di-(2-ethylhexyl)phthalate), DEHTP (di-(2-ethylhexyl)terephthalate) and TEHTM (tri-(2-ethylhexyl)trimellitate) metabolites as biomarkers of this exposure during and after the newborns' stay in NICU. Daily urinary samples were collected in NICU and at discharge from the hospital for each patient. MD sources and exposure factors were also investigated. 508 urinary samples from 97 patients enrolled in centres 1 and 2 (C1/C2) were collected. The exposure of newborns to DEHP was greater than that of DEHTP and TEHTM, with a median concentration of DEHP metabolites (C1:195.63 ng/mL;C2:450.87 ng/mL) respectively 5 to 10 times higher and 57 to 228 times higher than the median concentrations of DEHTP and TEHTM metabolites. The urinary concentrations of DEHP and TEHTM metabolites were significantly lower at discharge than in NICU, with a 18-and 35-fold decrease for DEHP and a 4 and 8-fold decrease for TEHTM, respectively for C1 and C2, but were similar for DEHTP metabolites. MD used for respiratory assistance, infusion therapy,enteral nutrition and transfusion were the main sources of exposure. Smaller gestational age and body weight significantly increased the newborns' exposure. The elevated levels of DEHP metabolites in NICU patients are still alarming. Additional efforts are necessary to promote its substitution in MD by possibly safer alternatives such as TEHTM and DEHTP, particularly when used for the care of newborns.

Simultaneous and sensitive determination of the main metabolites of the plasticizer DEHP and its substitutes DEHTP, DINCH and TEHTM in human urine by coupling of on-line SPE, UHPLC and tandem mass spectrometry

With the prominent but toxicologically critical plasticizer di-(2-ethylhexyl) phthalate (DEHP) declining, alternative plasticizers are increasingly used leading to a continuously more diverse exposure situation of humans with multiple plasticizers. Therefore, an on-line SPE-LC-MS/MS method for the simultaneous determination of the most relevant urinary biomarkers of exposure to DEHP and the alternative plasticizers 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), di-(2-ethylhexyl) terephthalate (DEHTP) and tri-(2-ethylhexyl) trimellitate (TEHTM) was developed. The method is characterized by a high sensitivity with limits of detection ranging from 0.006 to 0.047 μg L^-1 combined with an easy and straightforward sample preparation procedure. The wide linear working range of the method enables a reliable determination of analyte background levels in the general population as well as its potential use for monitoring studies investigating elevated plasticizer exposure settings. The method was successfully applied to urine samples from ten volunteers without occupational exposure to plasticizers revealing ubiquitous background exposure levels of the common plasticizers DEHP, DEHTP and DINCH.

In vitro and in silico approach to study the hormonal activities of the alternative plasticizer tri-(2-ethylhexyl) trimellitate TEHTM and its metabolites

Tri-(2-ethylhexyl) trimellitate (TEHTM) is a plasticizer for polyvinyl chloride (PVC) material used in medical devices. It is an alternative to di-(2-ethylhexyl) phthalate (DEHP), a well-known reprotoxic and endocrine disruptor. As plasticizers are known to easily migrate when in contact with fatty biological fluids, patient exposure to TEHTM is highly probable. However, there is currently no data on the potential endocrine-disrupting effects of its human metabolites. To evaluate the effects of TEHTM metabolites on endocrine activity, they were first synthesized and their effects on estrogen, androgen and thyroid receptors, as well as steroid synthesis, were investigated by combining in vitro and in silico approaches. Among the primary metabolites, only 4-MEHTM (4-mono-(2-ethylhexyl) trimellitate) showed agonist activities on ERs and TRs, while three diesters were TR antagonists at non-cytotoxic concentrations. These results were completed by docking experiments which specified the ER and TR isoforms involved. A mixture of 2/1-MEHTM significantly increased the estradiol level and reduced the testosterone level in H295R cell culture supernatants. The oxidized secondary metabolites of TEHTM had no effect on ER, AR, TR receptors or on steroid hormone synthesis. Among the fourteen metabolites, these data showed that two of them (4-MEHTM and 2/1-MEHTM) induced effect on hormonal activities in vitro. However, by comparing the concentrations of the primary metabolites found in human urine with the active concentrations determined in bioassays, it can be suggested that the metabolites will not be active with regard to estrogen, androgen, thyroid receptors and steroidogenesis-mediated effects.

Impact of the pathogen inactivation process on the migration of di(2-ethylhexyl) phthalate from plasma bags

BACKGROUND AND OBJECTIVES

Di(2-ethylhexyl) phthalate (DEHP) is a toxic plasticizer that is commonly used in the manufacture of polyvinyl chloride (PVC) blood bags. It is well known that DEHP can migrate from a medical device into the blood plasma. For safety reasons, pathogens in plasma must be inactivated; however, this process may increase DEHP migration. Here, we assessed the impact of illumination-based pathogen inactivation on the migration of DEHP from PVC bags into plasma.

MATERIALS AND METHODS

Pairs of native PVC-DEHP plasma bags were pooled. Each pool was then split into a pathogen-inactivated bag and a control bag. After illumination, the plasma concentrations of DEHP and its main metabolite (mono(2-ethylhexyl) phthalate, MEHP) in each bag were assayed and compared using liquid chromatography-tandem mass spectrometry. Concentrations were evaluated in repeated-measures, two-way analyses of variance.

RESULTS

The MEHP concentration was significantly associated with storage but not with illumination (p = 0.0001). The DEHP concentration stayed constant throughout the storage period. The DEHP equivalent concentration (corresponding to the overall plasticizer migration rate into plasma) was not significantly associated with illumination (p = 0.3) or storage (p = 0.09; mean ± standard deviation of the mean DEHP concentration for all conditions: 147.9 ± 11.3 μg/ml).

CONCLUSION

Illumination-based inactivation of pathogens in plasma did not increase the DEHP equivalent concentration, relative to control (non-inactivated) plasma.

Advanced hemodialysis equipment for more eco-friendly dialysis

Healthcare in general and dialysis care in particular are contributing to resource consumption and, thus, have a notable environmental footprint. Dialysis is a life-saving therapy but it entails the use of a broad range of consumables generating waste, and consumption of water and energy for the dialysis process. Various stakeholders in the healthcare sector are called upon to develop and to take measures to save resources and to make healthcare and dialysis more sustainable. Among these stakeholders are manufacturers of dialysis equipment and water purification systems. Dialysis equipment and consumables, together with care processes need to be advanced to reduce waste generation, enhance recyclability, optimize water purification efficiency and water use. Joint efforts should thus pave the way to enable delivering green dialysis and to contribute to environmentally sustainable health care.

Metabolites of 4-methylbenzylidene camphor (4-MBC), butylated hydroxytoluene (BHT), and tris(2-ethylhexyl) trimellitate (TOTM) in urine of children and adolescents in Germany - human biomonitoring results of the German Environmental Survey GerES V (2014-2017)

The UV filter 4-methylbenzylidene camphor (4-MBC), used in cosmetics, the antioxidant butylated hydroxytoluene (BHT), used inter alia as a food additive and in cosmetics, and the plasticizer tris(2-ethylhexyl) trimellitate (TOTM), used mainly in medical devices as substitute for di-(2-ethylhexyl) phthalate (DEHP), are suspected to have endocrine disrupting effects. Human biomonitoring methods that allow for assessing the internal exposure of the general population to these substances were recently developed in a German cooperation to enhance the use of human biomonitoring. First-morning void urine samples from 3- to 17-year-old children and adolescents living in Germany were analysed for metabolites of 4-MBC (N = 447), BHT (N = 2091), and TOTM (N = 431) in the population-representative German Environmental Survey on Children and Adolescents 2014-2017 (GerES V). 4-MBC metabolites were found in quantifiable amounts only in single cases and exposure levels remained well below health-based guidance values. In contrast, ubiquitous exposure to BHT became evident with a geometric mean (GM) urinary concentration of the metabolite BHT acid of 2.346 μg/L (1.989 μg/g_creatinine) and a maximum concentration of 248 μg/L (269 μg/g_crea). The highest GM concentration was found in young children aged 3-5 years, yet no specific sources of exposure could be identified. Also, TOTM metabolites were found in quantifiable amounts only in very few samples. None of these findings could be related to previous hospital treatment or exposure via house dust. The presented results will be the basis to derive reference values for exposure of children and adolescents in Germany to BHT and will facilitate to identify changing exposure levels in the general population.

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

Aim and scope:

Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey.

Materials and Methods:

Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes.

Results:

This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively.

Conclusion:

Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

How does continuous venovenous hemofiltration theoretically expose (ex-vivo models) inpatients to diethylhexyladipate, a plasticizer of PVC medical devices?

Continuous venovenous hemofiltration (CVVH) is widely used in intensive care units to treat patients with acute kidney injury requiring renal replacement therapy. The medical devices (MD) used for CVVH include a hemofilter and tubings made of plasticized PVC. Due to its known reprotoxicity, diethylhexyl phthalate (DEHP) has been replaced by alternatives such as diethylhexyladipate (DEHA) in some of these tubings. The migration of DEHA from hemofiltration systems has not been assessed and thus the level of patient exposure to this DEHP-alternative remains unknown. In this study, 2 CVVH models were used to evaluate the potential migration of DEHA from PVC tubings, allowing the determination of (Rachoin and Weisberg, 2019) the highest rates of DEHA able to migrate into a simulant flowing in a marketed adult CVVH circuit by disregarding any metabolisation and (Krieter et al., 2013) the clinical-reflecting exposure of patients to this plasticizer and its metabolites by assessing their migration into blood. In the first model, we showed that patients undergoing a CVVH procedure may be exposed to high rates of DEHA. Moreover, DEHA is continuously hydrolyzed into its primary metabolite MEHA (monoethylhexyladipate), which may reach cytotoxic level in the patients' blood. When looking from a « safer » MD perspective, DEHA might not be the best alternative plasticizer for CVVH tubings. However, to reflect clinical conditions, this study should be completed by an in-vivo evaluation (biomonitoring) of the oxidized metabolites of DEHA in urines of inpatients undergoing CVVH.

Plasticizer exposure of infants during cardiac surgery

In the present study we investigated the internal exposure situation of infant patients to the plasticizers TEHTM (tri-2-ethylhexyl trimellitate) and DEHP (di-2-ethylhexyl phthalate). The study collective included 21 infant patients aged 2-22 months that had to undergo cardiac surgery using cardio pulmonary bypass (CPB). Each patient, but one, received blood products during surgery. A special feature was that the used CPB tubings were exclusively plasticized with the alternative plasticizer TEHTM and were free of the standard plasticizer DEHP, that raises increasing toxicological concern. The blood products were stored in DEHP plasticized blood bags. Blood and urine samples of each infant patient were analysed before and after the surgery for the levels of the plasticizers DEHP and TEHTM and their metabolites. In general, the plasticizers were detected in the post-surgery blood samples only, with TEHTM in low levels (median 18.4 μg/L) and DEHP in rather elevated levels (median 1046 μg/L). With respect to the urine samples, TEHTM metabolites were not detected in any of the samples. DEHP metabolites were found in all urine samples, however, in significantly increased median levels in the post-surgery urine samples of the infants (increase factor 5-26). Thus, the present study clearly demonstrates the strong contribution of standard medical procedures to the internal plasticizer burden of patients. Particularly with regard to the suspected endocrine disrupting activities of the phthalate plasticizer DEHP, the elevated internal levels of this plasticizer and its metabolites in infants following cardiac surgery are alarming.

Interactions of amphiphiles with plasticisers used in polymers: Understanding the basis of health and environmental challenges

Plasticisers are widely used to provide desirable mechanical properties of many polymeric materials. These small molecule additives are also known to leach from the finished products, and this not only may modify the physical properties but the distribution of these materials in the environment and in the human body can cause long-term health concerns and environmental challenges. Many of these plasticisers are esters of polyvalent acids and phthalic acid has previously been predominant but various alternatives are now being more widely explored. The eventual distribution of these compounds depends not just on solubility in aqueous media and on vapour pressure but also on their interaction with other materials, particularly lipids and amphiphiles. This review provides an overview of both the basic physical data (solubility, partition coefficients, surface tension, vapour pressure) that is available in the literature and summarises what has been learnt about the molecular interactions of various plasticisers with surfactants and lipids.

Exposure of patients to di(2-ethylhexy)phthalate (DEHP) and its metabolite MEHP during extracorporeal membrane oxygenation (ECMO) therapy

The plasticizer di(2-ethylhexyl)phthalate (DEHP) is often used for PVC medical devices, that are also largely used for intensive care medical treatments, like extracorporeal membrane oxygenation (ECMO) therapy. Due to the toxicological potential of DEHP, the inner exposure of patients with this plasticizer is a strong matter of concern as many studies have shown a high leaching potential of DEHP into blood. In this study, the inner DEHP exposure of patients undergoing ECMO treatment was investigated. The determined DEHP blood levels of ECMO patients and the patients of the control group ranged from 31.5 to 1009 μg/L (median 156.0 μg/L) and from 19.4 to 75.3 μg/L (median 36.4 μg/L), respectively. MEHP blood levels were determined to range from < LOD to 475 μg/L (median 15.9 μg/L) in ECMO patients and from < LOD to 9.9 μg/L (median 3.7 μg/L) in the control group patients, respectively. Increased DEHP exposure was associated with the number of cannulas and membranes of the ECMO setting, whereas residual diuresis decreased the exposure. Due to the suspected toxicological potential of DEHP, its use in medical devices should be further investigated, in particular for ICU patients with long-term exposure to PVC, like in ECMO therapy.

Simultaneous determination of di(2-ethylhexyl) phthalate and diisononylcyclohexane-1,2-dicarboxylate and their monoester metabolites in four labile blood products by liquid chromatography tandem mass spectrometry

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer that is largely used for PVC blood bags. The migration of DEHP from medical devices into labile blood products (LBP) is a well-known situation. While DEHP has beneficial effects on the storage of red blood cells, it can have toxicological impact due to its potential reprotoxic effects (classified group 1B). Since July 1st, 2015, the French law prohibits the use of tubing made in DEHP-plasticized PVC in paediatric, neonatal and maternity wards. This provision, which could extend in several years more widely to medical devices used for drugs infusion, dialysis, feeding and blood bags, has led manufacturers to replace DEHP to alternative plasticizers such as diisononylcyclohexane-1,2-dicarboxylate (DINCH). In this paper, a liquid chromatography-tandem mass spectrometry (LCMS/MS) method has been developed and validated for the determination of DEHP, DINCH and their corresponding monoester metabolites (MEHP and MINCH) in four labile blood products (LBP): whole blood (WB), red cells concentrate (RCC), plasma and platelet concentrate (PC). Due to strong contamination of blank LBP by DEHP because of its ubiquitous presence in working environment and despite the attention paid to avoid contamination of solvents and glassware, a trap chromatographic column was implemented between the solvent mixing chamber and the injector of the LC system. This set-up permitted to discriminate DEHP present in the sample to DEHP brought by the environmental contamination. In the optimized conditions, all compounds were separated in less than 10 min. The analytes were extracted from LBP samples using a liquid-liquid extraction. After optimization, recoveries were ranged from 47 to 96 %, depending on the analytes and the nature of LBP. Except for DEHP which exhibited RSD values of intermediate precision higher than 20 % at a concentration of 25 nM, all the precision results (repeatability and intermediate precision) were lower than 16 % and trueness values ranged from -16.2-19.8%. Using the validated method, the leachability of DEHP and DINCH from corresponding PVC-blood bags was investigated and the concentrations of their corresponding metabolites, MEHP and MINCH, were determined in whole blood, red cells concentrate, plasma and platelet concentrate.

Reduction of exposure to plasticizers in stored red blood cell units

Introduction:

Plastic can be toxic and hazardous to an organism’s health, but it is being widely used in our daily lives. Di-2-ethylhexyl-phthalate is the most common plasticizer in medical devices made of polyvinylchloride and is commonly found in soft bags storing red blood cell units. Di-2-ethylhexyl-phthalate and its degradation product mono-2-ethylhexyl-phthalate can migrate into human body fluids, for example, blood and tissues. The aim of the study was to assess the concentration of plasticizers in red blood cell units according to storage time and after mechanical rinsing using a cell salvage device.

Methods:

Levels of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate were analysed in 50 unwashed red blood cell units using liquid chromatography coupled with tandem mass spectrometry. In addition, phthalate concentrations were measured before and after mechanical rinsing in six more washed red blood cell units with storage times ranging between 36 and 56 days. A linear regression model was determined by the daily increase of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate in the stored red blood cell units subject to their storage time (range = 4-38 days), and the effect of mechanical rinsing on their phthalate concentration was calculated.

Results:

A linear correlation was found between storage time of unwashed red blood cell units and the concentration of di-2-ethylhexyl-phthalate (p < 0.001) or mono-2-ethylhexyl-phthalate (p < 0.001). Stored red blood cell units older than 14 days had significantly higher concentrations of both contaminants than red blood cell units of shorter storage time (p < 0.001). Mechanical rinsing in washed red blood cell units attained a reduction in the di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate concentration by a median of 53% (range = 18-68%; p = 0.031) and 87% (range = 68-96%; p = 0.031), respectively.

Conclusion:

Leaching of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate into red blood cell units depends on the duration of storage time. Plasticizers can be significantly reduced by mechanical rinsing using cell salvage devices, and thus, red blood cell units can be regenerated with respect to chemical contamination.

New SPE-LC-MS/MS method for the simultaneous determination in urine of 22 metabolites of DEHP and alternative plasticizers from PVC medical devices

DiEthylHexylPhthalate (DEHP) can leach out of plasticized PVC medical devices (MD) and may enter into contact with patients. This phthalate is known for its reprotoxic and endocrine disrupting effects. Its use in medical devices (MD) has been restricted and alternative plasticizers have been developed. Nevertheless, no published clinical studies exist concerning patient exposure to these alternative plasticizers during medical care. This is particularly worrisome when high-risk populations, such as newborns, are exposed to these new plasticizers in intensive care units. Our study aimed to develop a novel sensitive and selective method to simultaneously identify and quantify DEHP and 17 other plasticizer metabolites (free or glucuronide conjugates), which are specific biomarkers of DEHTP, TOTM, DINP, DINCH and DEHA exposure in human urine. This robust method uses turbulent-flow online extraction technology coupled to high performance liquid chromatography - tandem mass spectrometry. Special care was taken to address two major problems in plasticizer analysis: contamination and chromatographic separation of interfering analogue structures. The validation was assessed in synthetic urine and the linearity of response was demonstrated for all compounds (R² > 0.99), with limits of quantification from 0.01 to 0.1 ng/ml. Accuracies ranged from 86% to 117% and inter- and intra-day precisions were <20%. The clinical applicability and suitability of our new method was assessed in patients in a neonatal intensive care unit to measure urinary concentrations of DEHP and alternative plasticizer metabolites. These metabolites were found in the majority of urine samples, with a median detection frequency of 95.2% (ranging from 12.5% to 100%). The high sensitivity, selectivity and ruggedness make the method suitable for large-scale biomonitoring studies of high-risk and general populations.

Isomeric separation and quantitation of di-(2-ethylhexyl) trimellitates and mono-(2-ethylhexyl) trimellitates in blood by LC-MS/MS

A new and fast HPLC-method for the simultaneous determination of tri-(2-ethylhexyl) trimellitate (TOTM or TEHTM), its diesters 2,4-di-(2-ethylhexyl) trimellitate (2,4-DEHTM), 1,4-di-(2-ethylhexyl) trimellitate (1,4-DEHTM), 1,2-di-(2-ethylhexyl) trimellitate (1,2-DEHTM) and monoesters 1-mono-(2-ethylhexyl) trimellitate (1-MEHTM), 2-mono-(2-ethylhexyl) trimellitate (2-MEHTM) and 4-mono-(2-ethylhexyl) trimellitate (4-MEHTM) together with di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) in blood was developed and validated. The analytes are extracted from blood using liquid-liquid extraction and are chromatographically separated by reversed-phase HPLC using core shell material. Quantitative assessment was performed by ESI-tandem mass spectrometry in negative ionization mode using stable isotope dilution. In less than 30min six postulated primary metabolites of TOTM along with the DEHP metabolite MEHP can be selectively and sensitively quantified. Additionally, the method enables the determination of the parent plasticizers TOTM and DEHP. The detection limits in blood were found to range between 0.7-5.5μg/L for all TOTM analytes. Precision and repeatability of the method were proven by relative standard deviations between 0.9% and 8.7%. TOTM, an alternative plasticizer to DEHP, is already increasingly used for medical devices. Nevertheless, data about the human metabolism of TOTM are still limited. The presented method is the first one enabling the simultaneous determination of the parent plasticizers TOTM and DEHP together with their primary degradation products (DEHTM, MEHTM, MEHP) and can thus be applied manifold including the investigation of the human metabolism of TOTM.

Exposure of hospitalised pregnant women to plasticizers contained in medical devices

Background

Medical devices (MDs) in polyvinyl chloride (PVC) are not a well-known source of exposure to plasticizers, in particular during pregnancy. Because of its toxicity, the di-(2-ethylhexyl) phthalate (DEHP) has been replaced by other plasticizers such as di (isononyl)-cyclohexane-1,2-dicarboxilic acid (DINCH), tri-octyltrimellitate (TOTM) and di-(isononyl) phthalate (DiNP). Our study aimed to quantify the plasticizers (DEHP and alternative plasticizers) contained in PVC medical devices used for hospitalised pregnant women and to describe which these MDs had been used (type, number, duration of exposure).

Methods

The plasticizers contained in the MDs used for daily care in the Obstetrics Department of a French University Hospital were extracted from PVC (after contact with a chloroform solution), identified and quantified by gas-chromatography-mass-spectrometry analysis. A total of 168 pregnant women hospitalised in the Obstetrics Department with at least one catheter were included in the observational study. The median number of MDs containing plasticizers used and the daily duration of exposure to the MDs were compared in three groups of pregnant women: “Pathology group” (women hospitalised for an obstetric disorder who did not give birth during this hospitalisation; n = 52), “Pathology and delivery group” (hospitalised for an obstetric disorder and who gave birth during this stay; n = 23) and “Delivery group” (admitted for planned or spontaneous delivery without obstetric disorder; n = 93).

Results

DiNP, TOTM and DINCH were the predominant plasticizers contained in the MDs at an amount of 29 to 36 g per 100 g of PVC. Women in the “Pathology group” (preterm labour or other pathology) were exposed to a median number of two MDs containing TOTM and one MD containing DiNP, fewer than those in the “Pathology and delivery group” (p < 0.05). Women in the “Pathology group” had a median exposure of 3.4 h/day to MDs containing DiNP and 8.2 h/day to MDs containing TOTM, longer than those in the “Delivery group” (p < 0.01).

Conclusions

Our study shows that the medical management of pregnant women in a hospital setting entails exposure to MDs containing alternative plasticizers (DiNP, TOTM and DINCH).

Electronic supplementary material

The online version of this article (doi:10.1186/s12905-017-0398-7) contains supplementary material, which is available to authorized users.

Characterization of the surface physico-chemistry of plasticized PVC used in blood bag and infusion tubing

Commercial infusion tubing and blood storage devices (tubing, blood and platelets bags) made of plasticized PVC were analyzed by spectroscopic, chromatographic and microscopic techniques in order to identify and quantify the additives added to the polymer (lubricants, thermal stabilizers, plasticizers) and to put into evidence their blooming onto the surface of the devices. For all the samples, deposits were observed on the surface but with different kinds of morphologies. Ethylene bis amide lubricant and metallic stearate stabilizers were implicated in the formation of these layers. In contact with aqueous media, these insoluble deposits were damaged, suggesting a possible particulate contamination of the infused solutions.

Leaching of plasticizers from polyvinylchloride perfusion lines by different lipid emulsions for premature infants under clinical conditions

Plasticizers migrate from polyvinylchloride (PVC) infusion systems into lipid emulsions. The aim of this study was to investigate the leaching of different plasticizers from PVC perfusion lines by a selection of lipid emulsions under clinical conditions. Seven PVC perfusion lines with an equal length of 150cm and three internal diameters were perfused with three lipid emulsions: Intralipid^® 20%, ClinOleic^® 20% and SMOFlipid^® 20%, mimicking clinical conditions. The concentrations of the plasticizers were measured directly in the emulsions by gas chromatography - mass spectrometry. Of the four plasticizers examined in this study, di (2-ethylhexyl) phthalate (DEHP) leached the most and was found, on average, at 46.5μg/ml in the emulsions - around one order of magnitude higher than the other plasticizers. This study demonstrates that the leaching of DEHP by lipid emulsions in conditions of total parenteral nutrition is many times higher than should be accepted and higher when compared to the other plasticizers. There was no significant difference in leaching of plasticizers in relation to the type of lipid emulsion. The influence of tube diameter on the leaching rate of plasticizers should be taken into account especially in particular exposed patients.

Human sex hormone-binding globulin as a potential target of alternate plasticizers: an in silico study

BACKGROUND

Currently, alternate plasticizers are used to replace phthalate plasticizers in children's toys, medical equipments and food packaging, due to the adverse effects of phthalate compounds on human health and laws prohibiting their use. Current information regarding the safety and potential adverse effects of alternate plasticizers is limited and recent studies have found alternate plasticizers to display similar characteristics to those observed in phthalate plasticizers. This study was undertaken to evaluate and predict the potential endocrine disrupting activity of the three most commonly used alternate plasticizers: di(2-ethylhexyl)terephthalate (DEHT), tris(2-ethylhexyl)trimellitate (TOTM), and diisononyl hexahydrophthalate (DINCH) against human sex hormone-binding globulin (SHBG) using in silico approaches.

MATERIALS AND METHODS

The crystal structure of human SHBG (Id: 1D2S) was retrieved from Protein Data Bank. PubChem database was searched for the structures of alternate plasticizers, DEHT, TOTM, and DINCH. Docking was performed using Glide (Schrodinger) Induced Fit Docking module.

RESULTS

Induced Fit Docking of three alternate plasticizer compounds indicated that each of the three compounds fitted well into the steroid binding pocket of SHBG. Docking displays showed interactions of alternate plasticizers with 25-30 amino-acid residues of SHBG; 18-20 amino residues overlapped between the natural ligand, DHT, and the three compounds (commonality of 82-91 %). The hydrogen-bonding interaction of the amino-acid residue, Asn-82, of SHBG was also present in displays of DHT and all the three alternate phthalates. The binding affinity of all the three alternate phthalates was higher than DHT; maximum in DINCH followed by TOTM and DEHT.

CONCLUSION

Our results suggested that the three alternate plasticizers have potential to engage the important interacting residues of SHBG and thus interfere in its steroid homeostatic function.

Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine

Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures.

Qualitative impact of salinity, UV radiation and turbulence on leaching of organic plastic additives from four common plastics - A lab experiment

Four common consumer plastic samples (polyethylene, polystyrene, polyethylene terephthalate, polyvinylchloride) were studied to investigate the impact of physical parameters such as turbulence, salinity and UV irradiance on leaching behavior of selected plastic components. Polymers were exposed to two different salinities (i.e. 0 and 35 g/kg), UV radiation and turbulence. Additives (e.g. bisphenol A, phthalates, citrates, and Irgafos® 168 phosphate) and oligomers were detected in initial plastics and aqueous extracts. Identification and quantification was performed by GC-FID/MS. Bisphenol A and citrate based additives are leached easier compared to phthalates. The print highly contributed to the chemical burden of the analyzed polyethylene bag. The study underlines a positive relationship between turbulence and magnitude of leaching. Salinity had a minor impact that differs for each analyte. Global annual release of additives from assessed plastics into marine environments is estimated to be between 35 and 917 tons, of which most are derived from plasticized polyvinylchloride.

Human exposure, hazard and risk of alternative plasticizers to phthalate esters

Alternative plasticizers to phthalate esters have been used for over a decade, but data regarding emissions, human exposure and health effects are limited. Here we review 20 alternative plasticizers in current use and their human exposure, hazard and risk. Physicochemical properties are collated for these diverse alternatives and log KOW values range over 15 orders of magnitude and log KAW and log KOA values over about 9 orders of magnitude. Most substances are hydrophobic with low volatility and are produced in high volumes for use in multiple applications. There is an increasing trend in the total use of alternative plasticizers in Sweden compared to common phthalate esters in the last 10 years, especially for DINCH. Evaluative indoor fate modeling reveals that most alternatives are distributed to vertical surfaces (e.g. walls or ceilings). Only TXIB and GTA are predicted to be predominantly distributed to indoor air. Human exposure data are lacking and clear evidence for human exposure only exists for DEHT and DINCH, which show increasing trends in body burdens. Human intake rates are collected and compared with limit values with resulting risk ratios below 1 except for infant's exposure to ESBO. PBT properties of the alternatives indicate mostly no reasons for concern, except that TEHPA is estimated to be persistent and TCP toxic. A caveat is that non-standard toxicological endpoint results are not available and, similar to phthalate esters, the alternatives are likely "pseudo-persistent". Key data gaps for more comprehensive risk assessment are identified and include: analytical methods to measure metabolites in biological fluids and tissues, toxicological information regarding non-standard endpoints such as endocrine disruption and a further refined exposure assessment in order to consider high risk groups such as infants, toddlers and children.

Transcriptome profiling and pathway analysis of hepatotoxicity induced by tris (2-ethylhexyl) trimellitate (TOTM) in mice

Tris (2-ethylhexyl) trimellitate (TOTM) is commonly used as an alternative plasticizer for medical devices. But very little information was available on its biological effects. In this study, we investigated toxicity effects of TOTM on hepatic differential gene expression analyzed by using high-throughput sequencing analysis for over-represented functions and phenotypically anchored to complementary histopathologic, and biochemical data in the liver of mice. Among 1668 candidate genes, 694 genes were up-regulated and 974 genes were down-regulated after TOTM exposure. Using Gene Ontology analysis, TOTM affected three processes: the cell cycle, metabolic process and oxidative activity. Furthermore, 11 key genes involved in the above processes were validated by real time PCR. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these genes were involved in the cell cycle pathway, lipid metabolism and oxidative process. It revealed the transcriptome gene expression response to TOTM exposure in mouse, and these data could contribute to provide a clearer understanding of the molecular mechanisms of TOTM-induced hepatotoxicity in human.

Studying DEHP migration in plasticized PVC used for blood bags by coupling Raman confocal microscopy to UV spectroscopy

Plasticized PVC is widely used to make medical devices such as tubing, perfusion bags and blood bags. By using confocal Raman microscopy on a PVC sheet plasticized with around 40% of di-(2-ethylhexyl)phthalate (DEHP), we propose a simple and sensitive approach to studying and understanding the diffusion of plasticizers from polymers into the surrounding media. Moreover, we sought to correlate our findings to standard measurements conducted by UV spectroscopy. This study showed differences in the concentration gradient observed due to the diffusion of the plasticizer inside a PVC sheet. We can thus follow the critical DEHP ratios that can impact the diffusion process. Water and ethanol were chosen as storage media: in ethanol, the lowest concentration of DEHP was observed at the surface resulting in the formation of a less plasticized layer near the interface; unlike ethanol, PVC sheets stored in water showed a greater concentration of DEHP on the film surface as an exudation of DEHP onto the surface.

Impact of the nature and concentration of plasticizers on the ability of PVC to sorb drug

The sorption of a drug by an infusion set may dramatically reduce the drug delivery efficiency. In this paper, we investigated how the drug sorption, in static conditions, is affected by the plasticizer's nature and ratio in the case of plasticized PVC, one of the most common material for infusion set tubing. Within the study, the drug concentration in diazepam solutions was studied after contact with PVC films containing different amounts of DEHP, DEHT, TOTM and DINCH® plasticizers. Moreover the partition coefficients between material and water were calculated. The drug sorption levels were equivalent for the different plasticizers and there was a plasticizer ratio for which the drug uptake was enhanced. As a consequence, the amount of sorbed drug might not be only linked to the amount of plasticizer in the film and to the solubility of the drug in the plasticizer alone: it must probably depend on specific interactions between plasticizer and PVC.

The effects of environmental chemicals on renal function

The global incidence of chronic kidney disease (CKD) is increasing among individuals of all ages. Despite advances in proteomics, genomics and metabolomics, there remains a lack of safe and effective drugs to reverse or stabilize renal function in patients with glomerular or tubulointerstitial causes of CKD. Consequently, modifiable risk factors that are associated with a progressive decline in kidney function need to be identified. Numerous reports have documented the adverse effects that occur in response to graded exposure to a wide range of environmental chemicals. This Review summarizes the effects of such chemicals on four aspects of cardiorenal function: albuminuria, glomerular filtration rate, blood pressure and serum uric acid concentration. We focus on compounds that individuals are likely to be exposed to as a consequence of normal consumer activities or medical treatment, namely phthalates, bisphenol A, polyfluorinated alkyl acids, dioxins and furans, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. Environmental exposure to these chemicals during everyday life could have adverse consequences on renal function and might contribute to progressive cumulative renal injury over a lifetime. Regulatory efforts should be made to limit individual exposure to environmental chemicals in an attempt to reduce the incidence of cardiorenal disease.

Migrability of PVC plasticizers from medical devices into a simulant of infused solutions

Medical devices (MD) for infusion and artificial nutrition are essentially made of plasticized PVC. The plasticizers in the PVC matrix can leach out into the infused solutions and may enter into contact with the patients. In order to assess the risk of patient exposure to these plasticizers we evaluated the migration performance of DEHP, DEHT, DINCH, and TOTM using a model adapted to the clinical use of the MDs. Each PVC tubing sample was immersed in a simulant consisting of a mixture of ethanol/water (50/50v/v) at 40°C and migration tests were carried out after 24h, 72h, and 10 days.DEHP had the highest migration ability, which increased over time. The amount of TOTM released was more than 20 times less than that of DEHP, which makes it an interesting alternative. DEHT is also promising, with a migration level three times smaller than DEHP. However, the migration ability of DINCH was similar to DEHP, with the released amounts equaling 1/8th of the initial amount in the tubing after 24h of contact. Taking into account the available toxicological data, TOTM and DEHT appear to be of particular interest. However, these data should be supplemented and correlated with clinical and toxicological studies on plasticizers and their metabolites.

Analytical methods for the determination of DEHP plasticizer alternatives present in medical devices: a review

Until 2010, diethylhexylphthalate (DEHP) was the plasticizer most commonly used to soften PVC medical devices (MDs), because of a good efficiency/cost ratio. In flexible plasticized PVC, phthalates are not chemically bound to PVC and they are released into the environment and thus may come into contact with patients. The European Directive 2007/47/CE, classified DEHP as a product with a toxicity risk and restricted its use in MDs. MD manufacturers were therefore forced to quickly find alternatives to DEHP to maintain the elasticity of PVC nutrition tubings, infusion sets and hemodialysis lines. Several replacement plasticizers, so-called "alternative to DEHP plasticizers" were incorporated into the MDs. Nowadays, the risk of exposure to these compounds for hospitalized patients, particularly in situations classified "at risk", has not yet been evaluated, because migrations studies, providing sufficient exposure and human toxicity data have not been performed. To assess the risk to patients of DEHP plasticizer alternatives, reliable analytical methods must be first developed in order to generate data that supports clinical studies being conducted in this area. After a brief introduction of the characteristics and toxicity of the selected plasticizers used currently in MDs, this review outlines recently analytical methods available to determine and quantify these plasticizers in several matrices, allowing the evaluation of potential risk and so risk management.

Screening study on hemolysis suppression effect of an alternative plasticizer for the development of a novel blood container made of polyvinyl chloride

The aim of this study is to identify a plasticizer that is effective in the suppression of the autohemolysis of the stored blood and can be used to replace di(2-ethylhexyl) phthalate (DEHP) in blood containers. The results of hemolysis test using mannitol-adenine-phosphate/red cell concentrates (MAP/RCC) spiked with plasticizers included phthalate, phthalate-like, trimeliate, citrate, and adipate derivatives revealed that di-isononyl-cyclohexane-1,2-dicarboxylate (Hexamoll(®) DINCH), di(2-ethylhexyl)-1,2,3,6-tetrahydro-phthalate (DOTP), and diisodecyl phthalate (DIDP) exhibited a hemolysis suppression effect almost equal to that of DEHP, but not other plasticizers. This finding suggested that the presence of 2 carboxy-ester groups at the ortho position on a 6-membered ring of carbon atoms may be required to exhibit such an effect. The hemolytic ratios of MAP/RCC-soaked polyvinyl chloride (PVC) sheets containing DEHP or different amounts of DINCH or DOTP were reduced to 10.9%, 9.2-12.4%, and 5.2-7.8%, respectively (MAP/RCC alone, 28.2%) after 10 weeks of incubation. The amount of plasticizer eluted from the PVC sheet was 53.1, 26.1-36.5, and 78.4-150 µg/mL for DEHP, DINCH, and DOTP, respectively. PVC sheets spiked with DIDP did not suppress the hemolysis induced by MAP/RCC because of low leachability (4.8-6.0 µg/mL). These results suggested that a specific structure of the plasticizer and the concentrations of least more than ∼10 µg/mL were required to suppress hemolysis due to MAP/RCC.

DEHP and its active metabolites: leaching from different tubing types, impact on proinflammatory cytokines and adhesion molecule expression. Is there a subsumable context?

Introduction: Di(2-ethylhexyl)phthalate (DEHP) is suspected to be toxic for several reasons. During contact with a lipophilic medium, DEHP leaks from polyvinylchloride (PVC), but its influence on inflammatory reactions remains unknown. We examined specific DEHP leaching out of different tubing types, the possibly modulated liberation of proinflammatory cytokines and the induction of adhesion molecule expression in primary endothelial cells.

Materials and Methods: Blood samples were circulated in traditional PVC, nodioctyl phthalate (DOP) PVC and heparin-coated PVC tubing within a Chandler loop model. The blood was tested for the concentration of DEHP and its active metabolites as well as the liberation of the proinflammatory cytokines TNFα and IL1ß. Furthermore, we exposed human endothelial cells to circulated blood and analysed them for the expression of the adhesion molecules ICAM-1, VCAM-1 and E-selectin.

Results: In contrast to the other tubing, PVC tubing showed significantly elevated DEHP levels, but no alteration was observed concerning a potential up-regulation of the cytokines or activation of the endothelial adhesion molecule receptors.

Conclusions: Our data conclude that there is no correlation between DEHP leaching and the inflammatory response after ECC support, but this study showed that even DEHP-free material is leaching DEHP and its toxic metabolites.

A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit

OBJECTIVE

To conduct an extensive literature and toxicological database review on substitute compounds and available alternative medical products to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate (DEHP), and conduct a DEHP-medical inventory analysis at a large metropolitan neonatal intensive care unit (NICU).

STUDY DESIGN

A systematic search for DEHP-free alternative products was performed using online databases. An informal audit of a large metropolitan NICU was undertaken in 2005 and 2006; 21 products were identified that could potentially contain DEHP. Availability of DEHP-free alternatives was determined through company websites and phone interviews.

RESULT

Two alternative approaches are available for replacing DEHP in NICU medical products: (1) replacement by DEHP-free plasticizers; and (2) replacement of PVC entirely through the use of other polymers. Both approaches seem to provide less harmful substitutes to DEHP, but support PVC-free polymers as the preferred alternative. However, significant data gaps exist, particularly for the alternative polymers. In all, 10 out of 21 (48%) products in the NICU audit were DEHP-free; six consisted of alternative polymers and four of alternative plasticizers. Of the remaining 11 products, only three were available without DEHP at the time of the audit.

CONCLUSION

Because of significant data gaps, systematic toxicological testing of DEHP-free alternatives is imperative. Continued development of alternative products is also needed.

Experimental study on infusion devices containing polyvinyl chloride: to what extent are they di(2-ethylhexyl)phthalate-free?

The use of medical devices containing highly criticized phthalates including di(2-ethylhexyl) phthalate (DEHP) has been challenged by European directive 2007/47/CE, put into effect in March 2010. New plasticizers are now being used to soften PVC in medical devices: trioctyltrimellitate (TOTM), di-isononyl-cyclohexan-1,2-dicarboxilate (DINCH) and di(2-ethylhexyl) terephthalate (DEHT). To quantify DEHP in nine DEHP-free medical devices made of PVC softened by alternative plasticizers, high performance liquid chromatography analysis with ultraviolet detection at 220 nm wavelength was achieved. An NMR spectroscopy was performed to confirm DEHP presence. Only two medical devices out of the nine tested were truly without DEHP. One of them showed traces of DEHP exceeding the threshold contamination of 0.1% in plastic mass set by REACH regulations. TOTM plasticizer is still incriminated when polyvinyl-chloride (PVC) is contaminated with DEHP. Manufacturers must verify the purity of their raw material, not only on PVC, but also on other soft plastics entering into the composition of medical infusion devices. The clinical consequences of exposure to certain levels of DEHP have not been evaluated. A solution could be to use alternative PVC-free materials.

Phthalate esters used as plasticizers in packed red blood cell storage bags may lead to progressive toxin exposure and the release of pro-inflammatory cytokines

Phthalate esters (PE's) are plasticizers used to soften PVC-based medical devices. PE's are the most abundant man-made pollutants and increase the risk of developing an allergic respiratory disease or a malignancy. The leaching of PE's in donated packed red blood cells (PRBC) during storage was assessed. PRBC transfusion bags containing CPD/AS-1 (ADSOL) buffer were analyzed. Samples were collected on storage day 1 and day 42. Two PE's, di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP), were measured by liquid chromatography coupled to mass spectrometry (LCMS). Interleukin-8 (IL-8) was measured by standard ELISA techniques. DEHP significantly increased from 34.3 µM (±20.0 SD) on day 1 to 433.2 µM (±131.2 SD) on day 42, a 12.6-fold increase. Similarly, MEHP significantly increased from 3.7 µM (±2.8 SD) on day 1 to 74.0 µM (±19.1 SD) on day 42, a 20.2-fold increase. Also, DEHP and MEHP increased the release of IL-8 from human umbilical vein endothelial cells (HUVEC). The transfusion of older units of PRBC could lead to an accumulation of PE's possibly resulting in inflammation and other effects. This accumulation could be exacerbated due to the decreased metabolism of PE's since trauma patients have a lower esterase activity, the enzymes responsible for metabolizing PE's. The effect of oxidative stress caused by PE's is discussed as a potential mechanism for increases in inflammation caused by older units of PRBC.

[Manufacturing waste of hemodialyzers decreases oxidative phosphorylation of mitochondria isolated from rats]

INTRODUCTION

The persistence of manufacturing waste in hemodialysers is a neglected aspect of lack of hemodialysis biocompatibility. The effect of waste was tested on mitochondria isolated from rat liver.

MATERIAL AND METHODS

After throwing the first two liters of the rinse solution of hemodialysers, the third liter is lyophilized. The waste is placed in the presence of mitochondria. The parameter V3 is the synthesis of ATP, the respiratory control (RC) is the ability to activate phosphorylation in the presence of ADP, ADP/O is the ratio of ADP used on oxygen consumption. The study was conducted on two hemodialyzers sterilized with gamma rays (Tricea and APS) and one hemodialyzer sterilized with flowing steam (FX60).

RESULTS

The respiratory parameters in the presence of waste are expressed as percentage of values obtained in the presence of control (sterile water). The respective values with Tricea, APS and the FX are for V3: 67±14, 79±10, and 81±8% (T vs A p=0.02; T vs F p=0.01; A vs F p=0.68) ; for CR : 44±6, 63±7, and 74±9% (T vs A p<0.001; T vs X p<0.001; A vs F p=0.004) ; for ADP/O : 75±11, 90±19, 91±11% (T vs A p=0.16; T vs F p=0.01; A vs F p=0.68). The dose-response curves confirm the differences concerning V3 and RC but not concerning ADP/O.

CONCLUSION

The hemodialyzers contain waste which has toxic effects on isolated mitochondria. This waste impairs the oxidative phosphorylation. The fact that this waste is still present in the dialyzers despite rinsing with two liters should alert users about the importance of extensive rinsing and manufacturers about the importance of effective procedures in order to eliminate manufacturing waste.

Simple surface sulfonation retards plasticiser migration and impacts upon blood/material contact activation processes

BACKGROUND

The use of Di-2-ethylhexyl phthalate (DEHP) plasticised polyvinyl chloride (DEHPPPVC) in medical devices persists despite evidence suggesting that DEHP migration can be harmful. Researchers have shown that a simple surface sulfonation process can retard the migration of DEHP, which may reduce the associated inflammatory response. The present study is designed to investigate the effects of surface sulfonation on DEHP migration and blood contact activation using in vitro and rodent models.

METHODS

The study was carried out in two phases: phase 1, in which the migration rate of DEHP from DEHPPPVC and sulfonated DEHP plasticised PVC (SDEHPPPVC) was measured; phase 2 of the study, in which the materials were incorporated into a rat recirculation biomaterial test model and blood samples taken to assess CD11b expression on neutrophils, IL-6 and Factor XIIa.

RESULTS

The initial DEHP concentration washed from the surface after storage was 37.19 +/- 1.17 mg/l in the PPVC group and 5.89 +/- 0.81 mg/l in the SPPVC group (p<0.0001). The post-wash migration rate was 3.07 +/- 0.32 mg/l/hour in the PPVC group compared to 0.46 +/- 0.038 mg/l/hour in the SPPVC group (p<0.0001). In phase 2 of the study, CD11b expression increased by 228.9% +/- 37% over the test period in the PPVC group compared to 118.3% +/- 46% in the SPPVC group (p<0.01). IL-6 levels rose from 3.1 +/- 1.4 pg/ml to 263 +/- 26 pg/ml in the PPVC group and 2.2 +/- 1.6 pg/ml to 161 +/- 29 pg/ml in the SPPVC group (p<0.01). Factor XIIa levels rose from 0.22 +/- 0.13 g/ml to 3.7 +/- 0.32 microg/ml and 0.28 +/- 0.09 to 2.71 +/- 0.21 microg/ml in the PPVC and SPPVC groups, respectively (p<0.05 at 90 minutes).

CONCLUSIONS

The simple sulfonation process significantly retards the migration of DEHP and is associated with the moderation of contact activation processes.