Tag Archive for: bisphenol A

bisphenol A

Alternative synthetic compound might offer safer solution to children’s health

bisphenol A

Not only is bisphenol A (BPA) added to medical equipment used to treat patients, it can also be found in 60% of neonatal intensive care unit (NICU) supplies, such as bandages and items for feeding, suggesting that occupational and clinical environments have a higher exposure to this synthetic compound.

Researchers at Children’s National Hospital found that a commonly used plastic, known as bisphenol S (BPS), was the least disruptive to cardiac electrophysiology and may serve as a safer chemical alternative for plastic medical devices used to treat vulnerable populations compared to other compounds, according to a new preclinical study published in Toxicological Sciences.

For decades, the medical device industry has used bisphenol chemicals known to antagonize ion channels, impair electrical conduction and trigger arrhythmias that affect the overall cardiovascular health in children. Not only is bisphenol A (BPA) added to medical equipment used to treat patients, it can also be found in 60% of neonatal intensive care unit (NICU) supplies, such as bandages and items for feeding, suggesting that occupational and clinical environments have a higher exposure to this synthetic compound.

Yet, very little is known about the downstream impact of BPA, BPS or bisphenol F (BPF) exposure on cardiac physiology.

To shed light on the safety profile of BPA and its alternatives BPS and BPF in plastic medical devices, Children’s National researchers present the first study that compares the acute effects of these three chemicals on cardiac electrophysiology in a preclinical model.

According to the researchers, children should continue receiving medical care to treat their condition.

“It is important to investigate iatrogenic plastic chemical exposures in young patients, as biomonitoring studies have reported elevated chemical exposures in NICU and pediatric intensive care unit patients,” said Devon Guerrelli, M.S., a Ph.D. candidate at Children’s National. “Our lab is actively working with cardiac surgeons to investigate patient exposure to both BPA and phthalate plasticizer chemicals. Patients and their parents can rest assured that our team’s priority is safety and advancement of the field.”

Future studies are needed to fully understand the chemicals’ safety on cardiac electrical and mechanical function due to notable biological differences between humans and preclinical models. The researchers call for the scientific community to explore the impact of these compounds on other organ systems by comprehensively assessing intracellular targets, genomic and proteomic expression profiles.

While health concerns remain, there is no consensus among the scientific community on the potential use of safer compound alternatives in pediatric plastic medical devices.

“First, a variety of preclinical models have been used by the scientific community to assess BPA toxicity. But, there is considerable variability between these different models, including differences in ion channel expression, which may produce conflicting results and limit extrapolation of the data to humans,” said Nikki Posnack, Ph.D., principal investigator at Children’s National Sheikh Zayed Institute for Pediatric Surgical Innovation and senior author. “Accordingly, in the presented study, we tested the effects of bisphenol chemicals using three different preclinical models. Second, studies assessing the safety profile of new structural analogs to BPA are limited.”

The researchers compared the cardiac safety profile of BPA, BPS and BPF by using a whole-cell voltage clamping recording on cell lines to study voltage-gated channels Nav1.5, Cav 1.2 and hERG, allowing the measurements of the cell’s electrical properties and total current through all the channels on a membrane in non-human subjects and cardiomyocytes human cell lines. Results of the study found that BPA was the most potent inhibitor of sodium, calcium and potassium channel currents compared to the alternatives BPS and BPF. BPA and BPF exposure also slowed atrioventricular conduction and increased atrioventricular nodal refractoriness.

“Based on our findings, acute exposure to high concentrations of BPA could lead to changes in cardiac electrophysiology,” said Tomas Prudencio, M.S., a research technician at Children’s National and lead author. “This includes slowing of electrical conduction from the atria to the ventricles, which would present as a prolongation of the PR interval in an electrocardiogram.”

baby with tubes

BPA analogues may be less likely to disrupt heart rhythm

Some chemical alternatives to plastic bisphenol-a (BPA), which is still commonly used in medical settings such as operating rooms and intensive care units, may be less disruptive to heart electrical function than BPA.

A poster at the AHA Scientific Sessions suggests bisphenol-s (BPS) and bisphenol-f (BPF) may have less impact on heart function than bisphenol-a (BPA).

Some chemical alternatives to plastic bisphenol-a (BPA), which is still commonly used in medical settings such as operating rooms and intensive care units, may be less disruptive to heart electrical function than BPA, according to a pre-clinical study that explored how the structural analogues bisphenol-s (BPS) and bisphenol-f (BPF) interact with the chemical and electrical functions of heart cells.

The findings suggest that in terms of toxicity for heart function, these chemicals that are similar in structure to BPA may actually be safer for medically fragile heart cells, such as those in children with congenital heart disease. Previous research has found a high likelihood that BPA exposure may impact the heart’s electrical conductivity and disrupt heart rhythm, and patients are often exposed to the plastic via clinical equipment found in intensive care and in the operating room.

“There are still many questions that need to be answered about the safety and efficacy of using chemicals that look and act like BPA in medical settings, especially in terms of their potential contribution to endocrine disruption,” says Nikki Gillum Posnack, Ph.D., the poster’s senior author and a principal investigator in the Sheikh Zayed Institute for Pediatric Surgical Innovation at Children’s National Hospital. “What we can say is that, in this initial pre-clinical investigation, it appears that these structural analogues have less of an impact on the electrical activity within the heart and therefore, may be less likely to contribute to dysrhythmias.”

Future studies will seek to quantify the risk that these alternative chemicals pose in vulnerable populations, including pediatric cardiology and cardiac surgery patients. Since pediatric patients’ hearts are still growing and developing, the interactions may be different than what was seen in this pilot study.

Learn more the impacts of exposure to plastics such as bisphenol-A and plasticizers such as DEHP and MEHP that are commonly used in medical devices:

###

Bisphenol-a Analogues May Be Safer Alternatives For Plastic Medical Products
Rafael Jaimes, Damon McCullough, Luther M Swift, Marissa Reilly, Morgan Burke, Jiansong Sheng, Javier Saiz, Nikki G Posnack
Poster Presentation by senior author Nikki G Posnack
CH.APS.01 – Translational Research in Congenital Heart Disease
AHA Scientific Sessions
November 16, 2019
1:30 p.m. – 2:00 p.m.

Nikki Gillum Posnack

Examining BPA’s impact on developing heart cells

Nikki Gillum Posnack

“We know that once this chemical enters the body, it can be bioactive and therefore can influence how heart cells function,” says Nikki Gillum Posnack, Ph.D. “This is the first study to look at the impact BPA exposure can have on heart cells that are still developing.”

More than 8 million pounds of bisphenol A (BPA), a common chemical used in manufacturing plastics, is produced each year for consumer goods and medical products. This endocrine disruptor reaches 90 percent of the population, and excessive exposure to BPA, e.g., plastic bottles, cash register receipts, and even deodorant, is associated with adverse cardiovascular events that range from heart arrhythmias and angina to atherosclerosis, the leading cause of death in the U.S.

To examine the impact BPA could have in children, researchers with Children’s National Heart Institute and the Sheikh Zayed Institute for Pediatric Surgical Innovation evaluated the short-term risks of BPA exposure in a preclinical setting. This experimental research finds developing heart cells respond to short-term BPA exposure with slowed heart rates, irregular heart rhythms and calcium instabilities.

While more research is needed to provide clinical recommendations, this preclinical model paves the way for future study designs to see if young patients exposed to BPA from medical devices or surgical procedures have adverse cardiac events and altered cardiac function.

“Existing research explores the impact endocrine disruptors, specifically BPA, have on adults and their cardiovascular and kidney function,” notes Nikki Gillum Posnack, Ph.D., a study author and assistant professor at Children’s National and The George Washington University. “We know that once this chemical enters the body, it can be bioactive and therefore can influence how heart cells function. This is the first study to look at the impact BPA exposure can have on heart cells that are still developing.”

The significance of this research is that plastics have revolutionized the way clinicians and surgeons treat young patients, especially patients with compromised immune or cardiac function.

Implications of Dr. Posnack’s future research may incentivize the development of alternative products used by medical device manufacturers and encourage the research community to study the impact of plastics on sensitive patient populations.

“It’s too early to tell how this research will impact the development of medical devices and equipment used in intensive care settings,” notes Dr. Posnack. “We do not want to interfere with clinical treatments, but, as scientists, we are curious about how medical products and materials can be improved. We are extending this research right now by examining the impact of short-term BPA exposure on human heart cells, which are developed from stem cells.”

This research, which appears as an online advance in Nature’s Scientific Reports, was supported by the National Institutes of Health under awards R00ES023477, RO1HL139472 and UL1TR000075, Children’s Research Institute and the Children’s National Heart Institute. NVIDIA Corporation provided GPUs, computational devices, for this study.