The ancient Greeks used snail mucus on the skin to combat local inflammation
Commonly used to repair damaged skin, products containing snail slime date back far beyond the age of social media — and may have potential beyond cosmetics, National Geographic reported.
Consumers worldwide are buying cosmetic products containing snail slime, with the global market estimated to be around $555 million in 2022.
Following the snail slime skin care boom in South Korea, the product – also called mucin or snail secretion – was widely shared on social media. North America is currently the fastest growing market for snail skin products. But using snail slime for glowing skin and good health dates back further than a social media trend.
The ancient Greeks used snail mucus on the skin to combat local inflammation. In the 1980s, Chilean snail farmers noted that processing snails for the French food market gave them softer hands and faster wound healing. This started the popularity of snail slime in South America.
What does snail mucus do to the skin?
“Garden snails, the most researched snail species for skin care, produce a slime that is touted as moisturizing, full of antioxidants and able to stimulate new collagen, which can reduce the signs of aging,” says Joshua Zeichner, a dermatologist at the Mount Hospital. Sinai.
According to dermatologist Elisabeth Bahar Haushmand, a member of the American Academy of Dermatology, consumers buy snail slime products to repair damaged skin and retain moisture. Mucus is full of natural vitamins A and E, antioxidants that can reduce inflammation and signs of aging, and has peptides that stimulate collagen production. However, Hashmand says larger clinical trials are needed to prove some of the mucilage’s purported effects and to better understand its active ingredients.
Snail mucus extract has been shown to create a protective barrier between the skin and polluted air. One study used a three-dimensional model of skin that had been exposed to ozone. The “skin” unprotected by the mucus extract became inflamed and showed signs of aging through oxidative stress, which causes wrinkles and uneven skin tone. Skin protected by the mucus extract showed less inflammation.
There is evidence that snail slime can help heal wounds and treat burns. Mucin also has antibacterial and antifungal properties.
Another study tested its ability to stop bacteria in wounds, with the mucus outperforming commercial antibiotics including amoxicillin and streptomycin. Early research suggests that it may also have anti-cancer abilities: garden snail slime successfully suppresses skin cancer cell growth in laboratory conditions.
Illustrative Photo by SİNAN ÖNDER: https://www.pexels.com/photo/shallow-focus-photography-of-brown-and-white-snail-on-moss-243128/
After the remark that Christ did not leave the parable “of resisting evil with force,” I began to be persuaded that in Christianity there were no soldier-martyrs executed for refusing to kill or take up arms.
I think this myth arose with the advent of the imperial version of Christianity. It is said that the warrior martyrs were executed only because they refused to offer sacrifices to the deities.
Indeed, among them there were those who completely refused to fight and kill, as well as those who fought with pagans but refused to use weapons against Christians. It is not acceptable to focus attention on why such a persistent myth arises.
Fortunately, the acts of the martyrs have been preserved, in which the trials of the first Christians (including against soldiers) are described in sufficient detail.
Unfortunately, few of the Russian Orthodox know them, and even fewer study them.
In fact, the lives of the saints are full of examples of conscientious objection to military service. Let me recall a few.
It was precisely because of his refusal to do military service that in 295 the holy warrior Maximilian was killed. The transcript of his trial is preserved in his Martyrology. In court he stated:
“I cannot fight for this world… I tell you, I am a Christian.”
In response, the proconsul pointed out that Christians served in the Roman army. Maximilian answers:
“That’s their job. I am also a Christian and I cannot serve.”
Likewise, St. Martin of Tours left the army after he was baptized. He is reported to have been summoned to Caesar for the presentation of a military award, but refused to accept it, saying:
“Until now I have served you as a soldier. Now let me serve Christ. Give the reward to others. They intend to fight, and I am a soldier of Christ and I am not allowed to fight.”
In a similar situation was the newly converted centurion St. Markel, who during a feast threw away his military honors with the words:
“I serve Jesus Christ, the eternal King. I will no longer serve your emperor, and I despise the worship of your gods of wood and stone, which are deaf and dumb idols.’
The materials from the trial against St. Markel have also been preserved. He is reported to have stated at this court that “… it is not fitting for a Christian who serves the Lord Christ to serve in the armies of the world.”
For refusing military service for Christian reasons, St. Kibi, St. Cadoc and St. Theagen were canonized. The latter suffered together with St. Jerome. He was an unusually brave and strong peasant who was drafted into the imperial army as a promising soldier. Jerome refused to serve, chased away those who came to recruit him, and together with eighteen other Christians, who also received a call to the army, hid in a cave. Imperial soldiers stormed the cave, but failed to capture the Christians by force. They take them out with cunning. They were indeed killed after refusing to offer sacrifices to idols, but this was rather the last point of their stubborn resistance to military service (a total of thirty-two Christian conscripts were executed that day).
The history of the legion in Thebes, which was under the command of St. Maurice, is more poorly documented. The acts of martyrdom against them are not preserved, as there was no trial. Only the oral tradition, recorded in the epistle of St. Bishop Eucherius, remains. Ten men of this legion are glorified by name. The rest are known by the general name of Agaun martyrs (not less than a thousand people). They have not completely refused to take up arms when fighting against heathen enemies. But they rebelled when they were ordered to put down a Christian rebellion.
They declared that they could not kill their Christian brothers under any circumstances and for any reason:
“We cannot stain our hands with the blood of innocent people (Christians). Are we an oath before God before we swear before you. You can’t have any confidence in our second oath if we break the other one, the first. You ordered us to kill Christians – look, we are the same.”
It was reported that the legion was thin and every tenth soldier was killed. After each new refusal, they killed every tenth again until they had slaughtered the entire legion.
St. John the Warrior did not completely retire from service, but in the army he was engaged in what in military parlance is called subversive activity – warning Christians about the next raid, facilitating escapes, visiting the brothers and sisters thrown into prison (however, according to his biography, we can assume that he did not have to shed blood: he was probably in the units guarding the city).
I think it would be an exaggeration to say that all early Christians were pacifists (if only because we don’t have enough historical material about the life of the Church from that time). During the first two centuries, however, their attitude to war, arms, and military service was so sharply negative that the ardent critic of Christianity, the philosopher Celsus, wrote: “If all men acted as you do, nothing would prevent the emperor from remaining completely alone and with troops deserted from him. The empire would fall into the hands of the most lawless barbarians.’
To which the Christian theologian Origen replies:
“Christians have been taught not to defend themselves against their enemies; and because they have kept the laws prescribing meekness and love to man, they have obtained from God what they could not have obtained if they had been allowed to wage war, though they might well have done so.’
We have to take into account one more point. That conscientious objectors did not become a major problem for the early Christians is largely explained not by their willingness to serve in the army, but by the fact that the emperors had no need to fill the regular army with conscripts.
Vasily Bolotov wrote about this: “The Roman legions were replenished with many volunteers who came to sign up.” Therefore, Christians could enter military service only in exceptional cases’.
The situation when Christians in the army became many, so that they already served in the imperial guard, occurred only at the end of the 3rd century.
It is not necessary that they entered the service after receiving Christian baptism. In most cases known to us, they became Christians while already being soldiers. And here indeed one such as Maximilian may find it impossible to continue in the service, and another will be compelled to remain in it, limiting the things he thinks he can do. For example, not to use weapons against brothers in Christ.
The limits of what is permissible for a soldier who has converted to Christianity were clearly described at the beginning of the 3rd century by St. Hippolytus of Rome in his canons (rules 10-15): “Regarding the magistrate and the soldier: never kill, even if you have received an order… A soldier on duty should not kill a man. If he is commanded, he must not carry out the command and must not take an oath. If he does not want it, let him be rejected. Let him who possesses the power of the sword, or is the magistrate of the city who wears the indigo, cease to exist or be rejected. Advertisers or believers who want to become soldiers must be rejected because they have despised God. A Christian should not become a soldier unless compelled by a sword-bearing chief. He must not burden himself with bloody sin. If, however, he has shed blood, he must not partake of the sacraments unless he is purified by penance, tears, and weeping. He must not act with cunning, but with the fear of God.”
Only with the passage of time did the Christian Church begin to change, to move away from the purity of the evangelical ideal, adapting to the demands of the world, which is alien to Christ.
And in the Christian monuments it is described how these changes take place. In particular, in the materials of the First Ecumenical (Nicaea) Council, we see how, with the adoption of Christianity as the state religion, those Christians who had previously retired from military service rushed into the army. Now they pay bribes to return (I remind you that military service was a prestigious job and well paid – apart from a good salary, the legionnaire was also entitled to an excellent pension).
At that time the Church still resented it. Rule 12 of the First Ecumenical Council calls such “apostates”: “Those who are called by grace to the profession of faith and have shown a first impulse of jealousy by taking off the military belts, but then, like a dog, have returned to their vomit , so that some even used money and gifts to be reinstated in the military rank: let them, after spending three years listening to the Scriptures in the portico, then ten years lie prostrate in the church, begging forgiveness”. Zonara, in his interpretation of this rule, adds that no one can remain in military service at all if he has not previously renounced the Christian faith.
A few decades later, however, St. Basil the Great hesitantly wrote about Christian soldiers returning from war: “Our fathers did not consider killing in battle to be murder, excusing, as it seems to me, the champions of chastity and piety. But perhaps it will be well to advise them, as having unclean hands, to abstain for three years from communion with the holy Mysteries.’
The Church is entering a period when it must balance between Christ and Caesar, trying to serve the One and not offend the other.
Thus arose the myth that the first Christians refrained from serving in the army only because they did not want to offer sacrifices to the gods.
And so we come to today’s myth that any soldier (not even a Christian) fighting for the “right cause” can be venerated as a martyr and saint.
Source: Author’s personal Facebook page, published on 23.08.2023.
The International Institute for Religious Freedom (IIRF) recently launched the Violent Incidents Database (VID), an initiative aimed at collecting, recording, and analyzing incidents related to violations of religious freedom across the globe. The VID aims to record violations of religious freedom on five continents, with an emphasis on tracking physical violence, but cannot claim exhaustive coverage. The data included in the VID is based on reports published in digital media available on the internet. Many incidents are never made public or do not receive sufficient attention from authorities or media. The database is constantly being updated as researchers identify religious freedom violations, but this is a complicated endeavour.
The VID discerns between two distinct types of religious freedom violations: physical violence and non-physical violence. Physical violence includes killings, torture, abductions, or similar assaults stemming from one’s religious identification. Non-physical violence might manifest as discriminatory legislation, social pressure, cultural marginalization, government discrimination, hindrances to conversion, obstacles to participation in public affairs, restrictions on religious life, or any symbolic or structural form of infringement. Both categories are important. You can read more about the methodology of the VID here.
Primarily utilizing publicly available digital media on the internet as its primary source, the VID supplements this information with field interviews, desk research, and reports from partner organizations. Additionally, individuals can contribute incident reports through an online form.
“Engagement for the freedom of religion or belief by Politics or Media should be grounded in the best available data, a realm exclusively provided by well-designed research. I take pride in the ongoing efforts of the current leadership team at IIRF, which has significantly expanded upon the modest beginnings of 15 years ago. The Violent Incidents Database, developed under their guidance, renders violations of religious freedom accessible to all, irrespective of the identities of victims or offenders and the locations of these incidents,” expressed Dr. Thomas Schirrmacher, Secretary General (CEO) of the World Evangelical Alliance and founder of the IIRF.
“We live in a world where the violent persecution of Christians and other religious groups is rampant and increasing,” said Dr. Ronald Boyd-MacMillan, Chief of Global Strategy and Research for Global Christian Relief, who also is Senior Research Fellow at the IIRF. “This database not only helps us track the violence but helps us better understand what persecuted Christians really need from their brothers and sisters around the world.”
The VID initially focused on gathering cases from Latin America, compiling incidents from the region dating back to 2002 was maintained by the Observatory of Religious Freedom in Latin America (OLIRE). OLIRE continues to partner with the IIRF to provide data for Latin America. Data on Nigeria is provided by the Observatory of Religious Freedom in Africa (ORFA). Thanks to the support and funding from Global Christian Relief, the IIRF has expended incident coverage to the rest of the globe, covering all five continents, and collecting incidents from 2021 to 2023.
The Violent Incidents Database will be highlighted during the International Religious Freedom Summit in Washington D.C., January 30-31.
Brussels, Belgium. The peaceful routine of Brussels was abruptly disturbed on Monday morning when farmers took to the streets in a protest that caused significant road closures. The mobilization of farmers in response to grievances has resulted in considerable disruptions across the country’s road network particularly at the entrance to Brussels according to a report from the federal road police.
By 9;00 AM blockages were reported on the ring of Brussels at Ruisbroek heading towards Waterloo. Traffic slowed down significantly with only the emergency lane remaining passable.
The traffic problems persisted on both the outer rings near Hal as farmers continued their blockade. This led commuters to experience delays of up to an hour due to resulting traffic jams. The Flemish Traffic Center (Verkeerscentrum) advised people to avoid the area if possible emphasizing the severity of the disruption.
Katrien Kiekens from the Flemish Agency for Roads and Traffic (Agentschap Wegen en Verkeer) highlighted how accessing the ring from E429 coming from Tournai had become “extremely challenging” due, to this situation.
The farmer’s protest in Belgium has led to a blockade at Hal situated in the Flemish Brabant region. This demonstration forms part of a movement by farmers across the northern roads of the country.
Guillaume Van Binst, who serves as the Secretary General of the Young Farmers Federation (FJA) announced that the blockade on the E19 at Hal would continue until the end of today. The protest began around 11;30 PM on Sunday. Farmers have started rotating shifts since early Monday. Van Binst explained that whether or not they continue depends on how their demands are addressed, implying that negotiations will determine if the protest extends further.
In Walloon Brabant province traffic was disrupted as authorities closed off the A7/E19 highway towards Brussels at Haut Ittre. A diversion has been instituted via the ring towards Zaventem. Additionally, tractors made their way into Brussels itself significantly raising awareness and visibility for this protest movement.
The unrest was not limited to Brussels alone. In the province, a convoy of tractors caused disruptions at Daussoulx exchange—a major motorway junction—bringing traffic to a halt on A4 E411 towards Brussels. Similar blockades and diversions were reported in other provinces including Luxembourg and Hainaut where tractors formed blockades at critical points such as border posts, with France.
The protests happening over the country highlight just how deeply the agricultural community feels about their grievances and their strong desire to be heard. Throughout the day as the blockade continues, its effects are being felt across Belgium. It’s not only commuters who are affected but also everyone engaged in discussions, about agricultural policies.
While negotiations are ongoing and the farmers remain determined the entire nation is anxiously waiting for a resolution that can alleviate tensions and restore the road network.
As reported in Cathobel, in an era where the future seems more uncertain than ever, young individuals stand at the crossroads of education and career, often overwhelmed by the plethora of paths available to them. Recognizing this challenge, 1RCF Belgium has launched an enlightening podcast episode, “Keys for Young People to Find Their Direction,” aimed at guiding the youth through the maze of professional orientation and decision-making.
Hosted by Florence Van Caillie and Delphine Lepour on the show “Près de Chez Vous Brabant wallon,” this episode shines a light on the pivotal moments of choosing a career and the educational journey that leads there. With the guidance of these experienced hosts, young listeners are provided with invaluable tools and advice to help clarify their aspirations and navigate the process of setting a solid foundation for their future careers.
The episode, presented by Isabelle Dumont, not only addresses the pressing concerns of young people but also introduces two specific tools designed to assist them in their quest for clarity. These resources, detailed in the podcast, serve as a beacon for those seeking to understand their interests, strengths, and how they align with potential career paths.
But “Keys for Young People to Find Their Direction” is just the tip of the iceberg in terms of the rich content available on 1RCF Belgium. The platform offers a variety of podcasts covering a wide range of topics, from the growing discontent among farmers across France and Europe to the intricate issues of bioethics, including the ethical debates surrounding surrogacy, euthanasia, and gender transition.
Listeners can also dive into discussions about the persecution of Christians, with an analysis provided by Lillia Djadi, an expert analyst of persecution in West Africa. The 2024 results of the World Index of Christian Persecution, indicating an increase in violence, offer a sobering reminder of the challenges faced by many around the globe.
Moreover, the podcast explores geopolitical shifts, exemplified by Sweden’s desire to join NATO for increased security amid regional tensions. Another poignant episode discusses the meeting between Prime Minister Alexander de Croo and the apostolic nuncio, highlighting the importance of addressing sensitive issues within the church.
Even the sin of gluttony is examined through a spiritual lens, offering listeners insights into how their relationship with food reflects their spiritual life. And for those interested in literary discussions, Philippe Besson’s novel “One Summer Evening” is reviewed, delving into themes of loss, memory, and the hope of reconnection.
1RCF Belgium’s latest podcast offerings are more than just entertainment; they are a source of guidance, insight, and reflection for listeners of all ages, particularly the youth standing at the threshold of their futures. With “Keys for Young People to Find Their Direction,” young individuals are encouraged to step forward with confidence, armed with the knowledge and tools to carve out their own paths in the world.
In a moment in German politics, the Free Democratic Party (FDP) and the Social Democratic Party (SPD) came together on Sunday to finalize their strategies for the upcoming European Union elections. The party conventions were marked by a sense of urgency and a call to action as both parties faced declining poll numbers and a shared determination to reinvigorate voter participation.
During the congresses held on January 28 both coalition partners officially approved their election platforms. Announced their leading candidates setting the stage for what is expected to be a fiercely competitive race. Chancellor Olaf Scholz, addressing the SPD gathering emphasized the significance of the forthcoming elections portraying them as a battleground against the rise of right-wing populism in Germany and throughout Europe.
With an approval rating currently standing at 13.5%, the SPD has made combating right ideologies a central pillar of its campaign. Katarina Barley, a politician who previously led the party’s efforts, in the 2019 European elections has once again been chosen to spearhead the SPD’s endeavours. Despite the difficulties faced in the past where the SPD experienced setbacks the party remains determined to turn things around and address the growing influence of illiberal forces within the EU. One vocal critic of Hungarian Prime Minister Victor Orbán’s tactics is Barley.
On a note, the FDP, whose support has dipped below the crucial 5% threshold is campaigning with a focus on reducing bureaucracy at the EU level. Marie Agnes Strack Zimmermann, their candidate strongly criticized Commission President Ursula von der Leyen’s administration for fostering a “madness of bureaucracy” that hampers innovation. The FDP also highlighted von der Leyen’s perceived alignment with policies by referring to her as “the Green Commission president ” aiming to differentiate their stance on regulatory reform.
These national campaigns take place against a political landscape in the EU that faces significant challenges, including a strained relationship with Hungary. Both the SPD and FDP have expressed concerns about Orbán’s behaviour and how the European Commission has handled this situation. In particular, there is controversy surrounding the decision to unfreeze EU funds for Hungary—a move seen by some as compromising the EU’s commitment, to democratic values.
As German political parties fine-tune their approaches and rally their supporters the upcoming EU elections become a moment not just for tackling internal political hurdles but also for shaping the future path of the European Union. From reforms to safeguarding democratic values, the results of these elections will undoubtedly hold significant consequences for Germany’s position, in Europe and the overall direction of the EU.
Finland and Ireland have recently launched a project called “Fostering Inclusive Quality Education in Finland and Ireland ” which is a significant step towards promoting inclusive education. This initiative, funded by the European Union through the Technical Support Instrument (TSI) and supported by the Agency began with an event in Dublin, Ireland on January 18 2024.
The main objective of this project is to strengthen the capacity of Finland and Ireland to create inclusive education systems. It aims to assist the Ministry of Education and Culture in Finland and the Department of Education in Ireland by identifying goals and planning actions to ensure equitable learning opportunities. The ultimate aim is to improve outcomes for all students regardless of their backgrounds or abilities.
The kick-off event marked the start of a journey towards achieving quality education in both countries. It brought together stakeholders from regional and local levels providing a platform for engagement in project activities and facilitating peer learning between relevant authorities at regional as well as national levels.
During the opening ceremony Josepha Madigan, Ireland‘s Minister of State, for Special Education and Inclusion delivered a video message.
She emphasized Ireland’s commitment to providing education and achieving the objectives of the project. She referred to a Policy Advice publication by the National Council for Special Education, which calls for systemic reforms. Madigan invited stakeholders to engage in a dialogue aimed at progressively achieving a more inclusive education system.
Mario Nava, the Director General of the European Commission’s Directorate General for Structural Reform Support (DG REFORM) echoed the dedication to inclusivity and highlighted how the TSI program contributes to strengthening inclusive education across the European Union through various projects.
Merja Mannerkoski, a Senior Specialist at Finland’s Ministry of Education and Culture reiterated Finland’s promise to ensure quality learning support provision throughout the country. She emphasized Finland’s reputation for excellence in education.
During the event, Professor Lani Florian from the University of Edinburgh delivered a keynote speech on inclusive education. Her presentation not only motivated participants but also encouraged further collaboration between national authorities and stakeholders to strengthen initiatives promoting inclusivity in education.
In the concluding discussions of the meeting, national stakeholders shared insights into their education system’s strengths and challenges. These conversations laid a foundation for identifying areas of focus throughout various stages of the project paving the way for transformative changes, in both Finland and Ireland’s educational landscapes. As Finland and Ireland set out on this endeavour the initiative serves as a symbol of optimism for the advancement of inclusive education offering a pathway to fair and equal learning opportunities, throughout Europe.
In a step towards empowering workers in multinational companies based in the European Union, the EU has introduced a set of transformative regulations to strengthen European Works Councils (EWCs). This move marks an era of workplace democracy focused on improving communication and decision-making between employees and employers.
The initiative places importance on EWCs, which play a crucial role in giving employees a voice in matters that transcend national boundaries. These councils address issues like company restructuring, labour shortages and the integration of technologies. With representation from over 11.3 million employees across Europe EWCs highlight the EU’s commitment to participatory workplace governance. However, despite their coverage that includes more, than half of the eligible workforce, there are still around 4,000 eligible companies that have yet to establish their EWCs.
The proposal put forth by the European Commission aims to revitalize the EWC framework through significant improvements.
Promoting Democratic Establishment of EWCs; The new rules strive to democratize the process of forming European Works Councils by granting equal rights to employees for initiating their creation. This proposed move has the potential to expand the benefits of European Works Councils (EWCs) to 5.4 million workers in 320 multinational companies. It aims to remove exemptions that limit worker participation.
One of the changes emphasizes the significance of timely and meaningful consultation between workers and multinational companies on matters directly impacting them. This fosters a transparent working environment.
Recognizing the role of resources in ensuring effective functioning the Commission proposes equipping these councils with the necessary tools and support to effectively fulfill their mandate.
To promote diversity and inclusivity the new rules include provisions for gender balance within European Works Councils. This reflects the EU’s commitment to achieving gender equality across all areas of work.
These anticipated reforms seek to enhance information flow and consultation thereby enriching strategic decision-making processes within companies while fostering mutual trust between management and workers. Additionally, these measures are designed to be cost-effective for companies without compromising their edge.
By taking these steps towards strengthening worker representation in multinational companies the EU establishes a precedent, for a more democratic, inclusive and resilient workplace culture.
This effort not only emphasizes the importance of collaborative training workshops in promoting improved work environments but also showcases the European Union’s strong commitment, to make sure that workers’ opinions are acknowledged and honoured in the international business arena.
The surprisingly strong effect could have implications for drug design and delivery.
The humble membranes that enclose our cells have a surprising superpower: They can push away nano-sized molecules that happen to approach them. A team including scientists at the National Institute of Standards and Technology (NIST) has figured out why, by using artificial membranes that mimic the behavior of natural ones. Their discovery could make a difference in how we design the many drug treatments that target our cells.
Cell membranes generate powerful electric field gradients that are largely responsible for repelling nano-sized particles like proteins from the surface of the cell — a repulsion that notably affects uncharged nanoparticles. In this schematic drawing, a negatively charged membrane (at top, in red) attracts small, positively charged molecules (purple circles), which crowd the membrane and push away a far larger, neutral nanoparticle (pink). Credit: N. Hanacek/NIST
The team’s findings, which appear in the Journal of the American Chemical Society, confirm that the powerful electrical fields that cell membranes generate are largely responsible for repelling nanoscale particles from the surface of the cell. This repulsion notably affects neutral, uncharged nanoparticles, in part because the smaller, charged molecules the electric field attracts crowd the membrane and push away the larger particles. Since many drug treatments are built around proteins and other nanoscale particles that target the membrane, the repulsion could play a role in the treatments’ effectiveness.
The findings provide the first direct evidence that the electric fields are responsible for the repulsion. According to NIST’s David Hoogerheide, the effect deserves greater attention from the scientific community.
“This repulsion, along with the related crowding that the smaller molecules exert, is likely to play a significant role in how molecules with a weak charge interact with biological membranes and other charged surfaces,” said Hoogerheide, a physicist at the NIST Center for Neutron Research (NCNR) and one of the paper’s authors. “This has implications for drug design and delivery, and for the behavior of particles in crowded environments at the nanometer scale.”
Membranes form boundaries in nearly all kinds of cells. Not only does a cell have an outer membrane that contains and protects the interior, but often there are other membranes inside, forming parts of organelles such as mitochondria and the Golgi apparatus. Understanding membranes is important to medical science, not least because proteins lodged in the cell membrane are frequent drug targets. Some membrane proteins are like gates that regulate what gets into and out of the cell.
The region near these membranes can be a busy place. Thousands of types of different molecules crowd each other and the cell membrane — and as anyone who has tried to push through a crowd knows, it can be tough going. Smaller molecules such as salts move with relative ease because they can fit into tighter spots, but larger molecules, such as proteins, are limited in their movements.
This sort of molecular crowding has become a very active scientific research topic, Hoogerheide said, because it plays a real-world role in how the cell functions. How a cell behaves depends on the delicate interplay of the ingredients in this cellular “soup.” Now, it appears that the cell membrane might have an effect too, sorting molecules near itself by size and charge.
“How does crowding affect the cell and its behavior?” he said. “How, for example, do molecules in this soup get sorted inside the cell, making some of them available for biological functions, but not others? The effect of the membrane could make a difference.”
While researchers commonly use electric fields to move and separate molecules — a technique called dielectrophoresis — scientists have paid scant attention to this effect at the nanoscale because it takes extremely powerful fields to move nanoparticles. But powerful fields are just what an electrically charged membrane generates.
“The electric field right near a membrane in a salty solution like our bodies produce can be astoundingly strong,” Hoogerheide said. “Its strength falls off rapidly with distance, creating large field gradients that we figured might repel nearby particles. So we used neutron beams to look into it.”
Neutrons can distinguish between different isotopes of hydrogen, and the team designed experiments that explored a membrane’s effect on nearby molecules of PEG, a polymer that forms chargeless nano-sized particles. Hydrogen is a major constituent of PEG, and by immersing the membrane and PEG into a solution of heavy water — which is made with deuterium in place of ordinary water’s hydrogen atoms — the team could measure how closely the PEG particles approached the membrane. They used a technique known as neutron reflectometry at the NCNR as well as instruments at Oak Ridge National Laboratory.
Together with molecular dynamics simulations, the experiments revealed the first-ever evidence that the membranes’ powerful field gradients were the culprit behind the repulsion: The PEG molecules were more strongly repelled from charged surfaces than from neutral surfaces.
While the findings do not reveal any fundamentally new physics, Hoogerheide said, they do show well-known physics in an unexpected place, and that should encourage scientists to take notice — and explore it further.
“We need to add this to our understanding of how things interact at the nanoscale,” he said. “We’ve demonstrated the strength and significance of this interaction. Now we need to investigate how it affects these crowded environments where so much biology happens.”
Paper: M. Aguilella-Arzo, D.P. Hoogerheide, M. Doucet, H. Wang and V.M. Aguilella. Charged biological membranes repel large neutral molecules by surface dielectrophoresis and counterion pressure. Journal of the American Chemical Society. Published online Jan. 16, 2024. DOI: 10.1021/jacs.3c12348
Are firefighters at risk of increased exposure to cancer-causing chemicals in their protective clothing?
Last year, a study by the National Institute of Standards and Technology (NIST) showed that the textiles used in protective clothing worn by firefighters often contain per- and polyfluoroalkyl substances, or PFAS, a class of chemicals that has been linked to an increased risk of cancer and other health effects.
A firefighter’s protective clothing includes three layers made of different types of textiles. A pair of studies by NIST has found that these textiles often contain potentially cancer-causing chemicals called PFAS and that they can release more of those chemicals when subject to simulated wear and tear. Credit: B. Hayes/NIST
Now, a follow-up study from NIST shows that the textiles used in that protective clothing, called turnout gear, tend to release more PFAS when they are subject to wear and tear. Taken together, the two studies identified the PFAS compounds present in selected turnout gear textiles, how much of each was present, and whether simulated wear and tear increased the amount of PFAS that the textiles released.
“The firefighter community has raised concerns about PFAS in turnout gear, but before these studies, there was very little data that address those concerns,” said NIST chemist and study co-author Rick Davis. “Based on these studies we can confidently say that more than 20 types of PFAS might be present in firefighter gear and that the amount and type of PFAS vary depending on the type of textile used and the amount of stress it has been subjected to.”
The NIST studies do not assess the health risks that firefighters might face due to the presence of PFAS in turnout gear. However, they provide previously unavailable data that toxicologists, epidemiologists and other health experts can use to assess those risks.
NIST conducted these studies at the behest of Congress, which called on NIST to study PFAS in firefighter gear in the 2021 National Defense Authorization Act.
PFAS are used in many products because they can make things resistant to oil, water and stains. They are often present in clothing, furniture, food packaging and nonstick cookware, among other things. They play a particularly important role in turnout gear by helping firefighters to do their job without getting totally drenched.
Because PFAS don’t break down in the environment, they are often referred to as “forever chemicals.” The Centers for Disease Control and Prevention has found that most Americans have detectable amounts of PFAS in their blood. Other studies have indicated that the blood of firefighters may have higher than average levels
of at least one type of PFAS. Research also suggests that firefighters may have a higher risk for certain types of cancer than the general population does, though that is not necessarily due to PFAS specifically.
Turnout gear includes pants, coats, gloves, boots and helmets. This study focused on the textiles used in pants and jackets, which typically contain three layers of material: a thermal layer nearest the body, a moisture barrier and an outer shell. In the earlier study, the researchers purchased 21 textiles that are typically used in each of these layers. They then tested those textiles for 53 different PFAS compounds and measured how much of each was present.
In the more recent study, the researchers stressed those same textiles using four techniques: abrasion, heat, laundering and weathering. The weathering was simulated by exposing the textiles to ultraviolet (UV) radiation and high humidity.
The researchers then measured the PFAS present after the textiles were stressed. The results showed that abrasion can cause measured PFAS concentrations to increase across all textiles tested. In addition, weathering and heat caused measured PFAS concentrations to increase in the outer shell materials. Finally, laundering had little effect, and in some cases reduced PFAS concentrations, presumably because PFAS were washed away into the wastewater.
Overall, both before and after stressing, measured PFAS concentrations were highest in outer shell fabrics that had been treated with a water-repellent coating. PFAS concentrations were lowest in the thermal layer, which is the layer nearest the firefighter’s body.
The researchers measured PFAS concentrations by first extracting PFAS from the textiles using a solvent. Based on this method, it is unclear what caused PFAS concentrations to change during stressing. Those changes might have been caused by chemical transformations, but it is also possible that stressing loosened the PFAS from the textile fibers, allowing more of it to be extracted.
Now that the researchers have measured PFAS in the textiles that have been stressed under highly controlled laboratory conditions, they are considering studying real gear that has been used for years. That may paint a more realistic picture, though a potentially more complicated one, as used gear might become contaminated with toxic compounds picked up at fire scenes.
Firefighter gear has to meet certain standards, including minimum requirements for water repellency. This research might point to new ways to meet those standards while reducing the risks of PFAS exposure. For instance, the amount and types of PFAS in the textiles varied from one manufacturer to the next, suggesting that some combinations might result in a lower risk of exposure than others. Or manufacturers might find alternative ways to meet the standards without relying on potentially toxic chemicals.
“Using PFAS in turnout gear may or may not be an acceptable risk, given all the other hazards that firefighters already face,” said NIST chemist and co-author John Kucklick. “This data will help people weigh those costs and benefits.”
