Tag Archives: antimicrobial

Skin sprays and dressings based on berry extracts and nanocellulose can prevent microbes

There’s an August 27, 2024 news item on Nanowerk that offers intriguing information about an application for nancellulose,

VTT [VTT Technical Research Centre of Finland] has developed a skin spray, based on nanocellulose and antimicrobial compounds from wild berries, which can be used to treat wounds and eliminate hospital-acquired bacteria such as MRSA [methicillin-resistant Staphylococcus aureus] before surgery. The product can also be applied as a cream, transdermal patch or wound dressing.

“The fast-acting surgical spray and efficacious dressing are based on a manufacturing process we have developed, where the surface and pores of a nanocellulose film are impregnated with a berry extract so that the antimicrobial compounds do not get trapped inside the fibre network. VTT has more than 15 years of experience in the laboratory-scale and pilot-scale manufacturing of nanocellulose gels and films”, says Panu Lahtinen, a Senior Scientist at VTT.

An August 27, 2024 VTT press release, which originated the news item, provides more detail about their nanocellulose/berry extract spray and what amounts to a business announcement,

The next step for the berry extract, which is produced using VTT InnoBerry Technologies™ manufacturing method, is to find companies interested in developing, producing and commercialising the products, so they can be launched onto the market in the next few years.
 

In nature, berry compounds protect the seed

The surface of berry seeds is rich in antimicrobial compounds, so berry extracts are useful for food, cosmetic and medical applications. The role of these compounds in nature is to protect the seed from microbes such as moulds before germination, but they can also help prevent the growth of dangerous microbes on human skin. Even a tiny amount of berry extract can kill pathogenic bacteria such as MRSA without harming the skin’s beneficial microbiota.

Berries are used to make juice, but significant quantities of press cake remain as a by-product after processing. This press cake contains the berry skin and seeds, which are rich in antimicrobial compounds. VTT has developed technologies to generate press-cake extracts enriched with these compounds, or to produce the key molecules in cultivated plant cells using plant biotechnology, which allows year-round production unaffected by variations in the berry harvest.

For more than 20 years, VTT has been studying the health benefits of arctic berries and their antimicrobial properties. These studies have shown that berries contain antimicrobial phenolic compounds, such as ellagitannins, that kill pathogenic bacteria effectively. Such compounds can be recovered from the press cake using VTT’s patented dry and wet fractionation technologies followed by environmentally friendly hydrothermal extraction without the use of harmful solvents. 

The berry extract developed by VTT can also replace the use of synthetic preservatives in cosmetics and nanosilver formulations in wound-care products. 

“Our research has identified antimicrobial compounds in several wild berries, including sea buckthorn, bilberry, strawberry, cloudberry, lingonberry and raspberry. Large-scale production is easiest to achieve from raspberry because there is sufficient raw material. To process the seeds, it’s necessary to find a company that is experienced in this task in the value chain,” says Kirsi-Marja Oksman-Caldentey, Associate Professor and Senior Advisor at VTT.

Antibiotic-resistant bacteria are one of the greatest medical challenges

The World Health Organization (WHO) includes antibiotic-resistant bacteria among the top ten global health challenges. There has been an increase in the number of difficult-to-treat wound infections caused by methicillin-resistant Staphylococcus aureus (MRSA), a severe pathogen. MRSA is quite common in the Finnish population, with around 20% of Finns unknowingly carrying these bacteria. If MRSA enters a wound, for example during surgery, it can be fatal.  

Scientific references

Natural antimicrobials from cloudberry (Rubus chamaemorus) seeds by sanding and hydrothermal extraction. ACS Food Sci. Technol. 

Reduction of methicillin-resistant Staphylococcus aureus biofilm growth and development by arctic berry extracts. Front. Cell. Infect. Microbiol.

Sanguiin H-6 fractionated from cloudberry (Rubus chamaemorus) seeds can prevent the methicillin-resistant Staphylococcus aureus biofilm development during wound infection. Antibiotics

I found more information about VTT on its What is VTT? webpage,

VTT is a visionary research and innovation partner for companies and society

VTT is one of Europe’s leading research institutions. We are owned by the Finnish state. We advance the utilisation and commercialisation of research and technology in commerce and society. Through scientific and technological means, we turn large global challenges into sustainable growth for businesses and society. We bring together people, business, science and technology to solve the biggest challenges of our time. This is how we create sustainable growth, jobs and wellbeing and bring exponential hope.

There’s a less exuberant description in the Wikipedia entry for the VTT Technical Research Centre of Finland, Note: Links have been removed,

VTT Technical Research Centre of Finland Ltd is a state-owned and controlled non-profit limited liability company.[5] VTT is the largest research and technology company and research centre conducting applied research in Finland. It provides research and innovation services and information for domestic and international customers and partners, both in private and public sectors.[6]

VTT is part of Finland’s innovation system and operates under the mandate of the Ministry of Economic Affairs and Employment.[7]

According to the Wikipedia entry’s ‘History’ subsection, VTT’s origin year is 1942.

Component of cinnamon essential oil for bacteria ‘nanokiller’

A May 23, 2024 news item on phys.org features an ‘intelligent nanokiller’,

A team of researchers from the Universitat Politècnica de València (UPV) and the CIBER de Bioingeniería, Biomaterials y Nanomedicine (CIBER-BBN) has developed an intelligent “nanokiller” based on a component of cinnamon essential oil (cinnamaldehyde) for use as an antimicrobial agent.

So far, the new nanodevice has shown significant efficacy against pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, and Candida albicans. It could be applied for the elimination of pathogens that may be present in food, wastewater and in the treatment of nosocomial infections, which are those acquired during hospital stays.

A May 24, 2024 Universitat Politècnica de València (UPV) press release (also on EurekAlert but published May 23, 2024), which originated the news item, further details the effects of this ‘nanokller’,

In the case of Escherichia coli, most strains are harmless, although some can cause severe abdominal cramping or acute diarrhea and vomiting. In the case of Staphylococcus aureus bacteria, its effects can be skin infections, bloodstream infections, osteomyelitis, or pneumonia. Meanwhile, Candida albicans is a fungus found in different biological fluids, causing diseases such as candidemia or invasive candidiasis.

Easy application

According to the team of the IDM-CIBER NanoSens group, applying this ” nanokiller ” would be very simple. “For example, we could create a spray, make a formulation based on water and other compounds, and apply it directly. We could make a water-based formulation in the field and spray it directly, like any pesticide today. And in hospitals, it could be applied on bandages, and we could even try to make a capsule that could be taken orally,” explains Andrea Bernardos, a researcher in the NanoSens group at the Inter-University Institute for Molecular Recognition Research and Technological Development (IDM).

High efficacy

The new nanodevice improves the efficacy of encapsulated cinnamaldehyde compared to the free compound: about 52-fold for Escherichia coli, about 60-fold for Staphylococcus aureus, and about 7-fold for Candida albicans.

“The increase in the antimicrobial activity of the essential oil component is possible thanks to the decrease in its volatility due to its encapsulation in a porous silica matrix and the increase in its local concentration when released due to the presence of the microorganisms,” highlights Andrea Bernardos, a researcher at the Inter-University Research Institute for Molecular Recognition and Technological Development (IDM).

It stands out for its high antimicrobial activity at very low doses, among its advantages. In addition, it enhances the antimicrobial properties of free cinnamaldehyde with a reduction of the biocidal dose of around 98% for bacterial strains (Escherichia coli and Staphylococcus aureus) and 72% for the yeast strain (Candida albicans) when the nanodevice is applied.

“Moreover, this type of device containing natural biocides (such as essential oil components) whose release is controlled by the presence of pathogens could also be applied in fields such as biomedicine, food technology, agriculture, and many others,” concludes Ángela Morellá-Aucejo, also an IDM researcher at the Universitat Politècnica de València.

The results of this study have been published in the journal Biomaterials Advances.

Here’s a link to and a citation for the paper,

Remarkable enhancement of cinnamaldehyde antimicrobial activity encapsulated in capped mesoporous nanoparticles: A new “nanokiller” approach in the era of antimicrobial resistance by Ángela Morellá-Aucejo, Serena Medaglia, María Ruiz-Rico, Ramón Martínez-Máñez, María Dolores Marcos, Andrea Bernardos. Biomaterials Advances Volume 160, June 2024, 213840 DOI: https://doi.org/10.1016/j.bioadv.2024.213840 Available online: 26 March 2024, Version of Record: 4 April 2024. Under a Creative Commons license

This paper is open access.

Cellulose nanocrystals (CNC), protein, and starch eletrospun to develop ‘smart’ food packaging

A December 29, 2021 news item on ScienceDaily announces research into ;smart’ sustainable packaging from a joint Nanyang Technical University and Harvard University,

A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) and Harvard T.H. Chan School of Public Health, US, has developed a ‘smart’ food packaging material that is biodegradable, sustainable and kills microbes that are harmful to humans. It could also extend the shelf-life of fresh fruit by two to three days.

The waterproof food packaging is made from a type of corn protein called zein, starch and other naturally derived biopolymers, infused with a cocktail of natural antimicrobial compounds. These include oil from thyme, a common herb used in cooking, and citric acid, which is commonly found in citrus fruits.

A December 28, 2021 Nanyang Technological University press release (PDF), also on EurekAlert but published December 27, 2021, which originated the news item, offers a few more details about the research (Note 1: Links have been removed; Note 2: I had to dig into the abstract to find the cellulose nanocrystals),

In lab experiments, when exposed to an increase in humidity or enzymes from harmful bacteria, the fibres in the packaging have been shown to release the natural antimicrobial compounds, killing common dangerous bacteria that contaminate food, such as E. Coli and Listeria, as well as fungi.

The packaging is designed to release the necessary miniscule amounts of antimicrobial compounds only in response to the presence of additional humidity or bacteria. This ensures that the packaging can endure several exposures, and last for months.

As the compounds combat any bacteria that grow on the surface of the packaging as well as on the food product itself, it has the potential to be used for a large variety of products, including ready-to-eat foods, raw meat, fruits, and vegetables.

In an experiment, strawberries that were wrapped in the packaging stayed fresh for seven days before developing mould, compared to counterparts that were kept in mainstream fruit plastic boxes, which only stayed fresh for four days.

The invention is the result of the collaboration by scientists from the NTU-Harvard T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology (NTU-Harvard SusNano), which brings together NTU and Harvard Chan School researchers to work on cutting edge applications in agriculture and food, with an emphasis on developing non-toxic and environmentally safe nanomaterials.

The development of this advanced food packaging material is part of the University’s efforts to promote sustainable food tech solutions, that is aligned with the NTU 2025 strategic plan, which aims to develop sustainable solutions to address some of humanity’s pressing grand challenges.

Professor Mary Chan, Director of NTU’s Centre of Antimicrobial Bioengineering, who co-led the project, said: “This invention would serve as a better option for packaging in the food industry, as it has demonstrated superior antimicrobial qualities in combatting a myriad of food-related bacteria and fungi that could be harmful to humans. The packaging can be applied to various produces such as fish, meat, vegetables, and fruits. The smart release of antimicrobials only when bacteria or high humidity is present, provides protection only when needed thus minimising the use of chemicals and preserving the natural composition of foods packaged.”

Professor Philip Demokritou, Adjunct Professor of Environmental Health at Harvard Chan School, who is also Director of Nanotechnology and Nanotoxicology Center and Co-director of NTU-Harvard Initiative on Sustainable Nanotechnology, who co-led the study, said: “Food safety and waste have become a major societal challenge of our times with immense public health and economic impact which compromises food security. One of the most efficient ways to enhance food safety and reduce spoilage and waste is to develop efficient biodegradable non-toxic food packaging materials. In this study, we used nature-derived compounds including biopolymers, non-toxic solvents, and nature-inspired antimicrobials and develop scalable systems to synthesise smart antimicrobial materials which can be used not only to enhance food safety and quality but also to eliminate the harm to the environment and health and reduce the use of non-biodegradable plastics at global level and promote sustainable agri-food systems.” 

Providing an independent assessment of the work done by the NTU research team, Mr Peter Barber, CEO of ComCrop, a Singapore company that pioneered urban rooftop farming, said: “The NTU-Harvard Chan School food packaging material would serve as a sustainable solution for companies like us who want to cut down on the usage of plastic and embrace greener alternatives. As ComCrop looks to ramp up product to boost Singapore’s food production capabilities, the volume of packaging we need will increase in sync, and switching to a material such as this would help us have double the impact. The wrapping’s antimicrobial properties, which could potentially extend the shelf life of our vegetables, would serve us well. The packaging material holds promise to the industry, and we look forward to learning more about the wrapping and possibly adopting it for our usage someday.”

The results of the study were published in the peer-reviewed academic journal ACS Applied Materials & Interfacesin October [2021].

Cutting down on packaging waste

The packaging industry is the largest and growing consumer of synthetic plastics derived from fossil fuels, with food packaging plastics accounting for the bulk of plastic waste that are polluting the environment.

In Singapore, packaging is a major source of trash, with data from Singapore’s National Environment Agency showing that out of the 1.76 million tonnes of waste disposed of by domestic sources in 2018, one third of it was packaging waste, and over half of it (55 per cent) was plastic.

The smart food package material, when scaled up, could serve as an alternative to cut down on the amount of plastic waste, as it is biodegradable. Its main ingredient, zein, is also produced from corn gluten meal, which is a waste by-product from using corn starch or oils in order to produce ethanol.

The food packaging material is produced by electrospinning[1] the zein, the antimicrobial compounds with cellulose, a natural polymer starch that makes up plant cell walls, and acetic acid, which is commonly found in vinegar.

Prof Mary Chan added: “The sustainable and biodegradable active food packaging, which has inbuilt technology to keep bacteria and fungus at bay, is of great importance to the food industry. It could serve as an environmentally friendly alternative to petroleum-based polymers used in commercial food packaging, such as plastic, which have a significant negative environmental impact.”

Prof Demokritou added: “Due to the globalisation of food supply and attitude shift towards a healthier lifestyle and environmentally friendly food packaging, there is a need to develop biodegradable, non-toxic and smart/responsive materials to enhance food safety and quality. Development of scalable synthesis platforms for developing food packaging materials that are composed of nature derived, biodegradable biopolymers and nature inspired antimicrobials, coupled with stimuli triggered approaches will meet the emerging societal needs to reduce food waste and enhance food safety and quality.”

The team of NTU and Harvard Chan School researchers hope to scale up their technology with an industrial partner, with the aim of commercialisation within the next few years.

They are also currently working on developing other technologies to develop biopolymer-based smart food package materials to enhance food safety and quality.

Here’s a link to and a citation for the paper, followed by the key (nanocellulose crystal mention) sentences in the abstract,

Enzyme- and Relative Humidity-Responsive Antimicrobial Fibers for Active Food Packaging by Zeynep Aytac, Jie Xu, Suresh Kumar Raman Pillai, Brian D. Eitzer, Tao Xu, Nachiket Vaze, Kee Woei Ng, Jason C. White, Mary B. Chan-Park, Yaguang Luo, and Philip Demokritou. ACS Appl. Mater. Interfaces 2021, 13, 42, 50298–50308 I: https://doi.org/10.1021/acsami.1c12319 Publication Date: October 14, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Excerpt from abstract,

Active food packaging materials that are sustainable, biodegradable, and capable of precise delivery of antimicrobial active ingredients (AIs) are in high demand. Here, we report the development of novel enzyme- and relative humidity (RH)-responsive antimicrobial fibers with an average diameter of 225 ± 50 nm, which can be deposited as a functional layer for packaging materials. Cellulose nanocrystals (CNCs) [emphasis mine], zein (protein), and starch were electrospun to form multistimuli-responsive fibers that incorporated a cocktail of both free nature-derived antimicrobials such as thyme oil, citric acid, and nisin and cyclodextrin-inclusion complexes (CD-ICs) of thyme oil, sorbic acid, and nisin. …

I have been following the CNC story for some time. If you’re curious, just use ‘cellulose nanocrystal(s)’ as your search term. You can find out more about ComCrop here.

Resisting silver’s microbial properties?

Yes, it is possible for bacteria to become resistant to silver nanoparticles. However, that yes comes with some qualifications according to a July 13, 2021 news item on ScienceDaily (Note: Links have been removed),

Antimicrobials are used to kill or slow the growth of bacteria, viruses and other microorganisms. They can be in the form of antibiotics, used to treat bodily infections, or as an additive or coating on commercial products used to keep germs at bay. These life-saving tools are essential to preventing and treating infections in humans, animals and plants, but they also pose a global threat to public health when microorganisms develop resistance to them, a concept known as antimicrobial resistance.

One of the main drivers of antimicrobial resistance is the misuse and overuse of antimicrobial agents, which includes silver nanoparticles, [emphases mine] an advanced material with well-documented antimicrobial properties. It is increasingly used in commercial products that boast enhanced germ-killing performance — it has been woven into textiles, coated onto toothbrushes, and even mixed into cosmetics as a preservative.

The Gilbertson Group at the University of Pittsburgh [Pennsylvania, US} Swanson School of Engineering used laboratory strains of E.coli to better understand bacterial resistance to silver nanoparticles and attempt to get ahead of the potential misuse of this material. The team recently published their results in Nature Nanotechnology.

Caption: A depiction of hyper-motile E.coli, a strain of bacteria found to resist silver nanoparticles’ antimicrobial properties after repeated exposure. Credit: Lisa Stabryla/University of Pittsburgh.

A July 13, 2021 University of Pittsburgh news release (also on EurekAlert), which originated the news item, provides more insight into the research,

“Bacterial resistance to silver nanoparticles is understudied, so our group looked at the mechanisms behind this event,” said Lisa Stabryla, lead author on the paper and a recent civil and environmental PhD graduate at Pitt. “This is a promising innovation to add to our arsenal of antimicrobials, but we need to consciously study it and perhaps regulate its use to avoid decreased efficacy like we’ve seen with some common antibiotics.”

Stabryla exposed E.coli to 20 consecutive days of silver nanoparticles and monitored bacterial growth over time. Nanoparticles are roughly 50 times smaller than a bacterium.

“In the beginning, bacteria could only survive at low concentrations of silver nanoparticles, but as the experiment continued, we found that they could survive at higher doses,” Stabryla noted. “Interestingly, we found that bacteria developed resistance to the silver nanoparticles but not their released silver ions alone.”

The group sequenced the genome of the E.coli that had been exposed to silver nanoparticles and found a mutation in a gene that corresponds to an efflux pump that pushes heavy metal ions out of the cell.

“It is possible that some form of silver is getting into the cell, and when it arrives, the cell mutates to quickly pump it out,” she added. “More work is needed to determine if researchers can perhaps overcome this mechanism of resistance through particle design.”

The group then studied two different types of E.coli: a hyper-motile strain that swims through its environment more quickly than normally motile bacteria and a non-motile strain that does not have physical means for moving around. They found that only the hyper-motile strain developed resistance.

“This finding could suggest that silver nanoparticles may be a good option to target certain types of bacteria, particularly non-motile strains,” Stabryla said.

In the end, bacteria will still find a way to evolve and evade antimicrobials. The hope is that an understanding of the mechanisms that lead to this evolution and a mindful use of new antimicrobials will lessen the impact of antimicrobial resistance.

“We are the first to look at bacterial motility effects on the ability to develop resistance to silver nanoparticles,” said Leanne Gilbertson, assistant professor of civil and environmental engineering at Pitt. “The observed difference is really interesting and merits further investigation to understand it and how to link the genetic response – the efflux pump regulation – to the bacteria’s ability to move in the system.

“The results are promising for being able to tune particle properties for a desired response, such as high efficacy while avoiding resistance.”

Here’s a link to and a citation for the paper,

Role of bacterial motility in differential resistance mechanisms of silver nanoparticles and silver ions by Lisa M. Stabryla, Kathryn A. Johnston, Nathan A. Diemler, Vaughn S. Cooper, Jill E. Millstone, Sarah-Jane Haig & Leanne M. Gilbertson. Nature Nanotechnology (2021) DOI: https://doi.org/10.1038/s41565-021-00929-w Published: 21 June 2021

This paper appears to be open access.

Reading (2 of 2): Is zinc-infused underwear healthier for women?

This first part of this Reading ‘series’, Reading (1 of 2): an artificial intelligence story in British Columbia (Canada) was mostly about how one type of story, in this case,based on a survey, is presented and placed in one or more media outlets. The desired outcome is for more funding by government and for more investors (they tucked in an ad for an upcoming artificial intelligence conference in British Columbia).

This story about zinc-infused underwear for women also uses science to prove its case and it, too, is about raising money. In this case, it’s a Kickstarter campaign to raise money.

If Huha’s (that’s the company name) claims for ‘zinc-infused mineral undies’ are to be believed, the answer is an unequivocal yes. The reality as per the current research on the topic is not quite as conclusive.

The semiotics (symbolism)

Huha features fruit alongside the pictures of their underwear. You’ll see an orange, papaya, and melon in the kickstarter campaign images and on the company website. It seems to be one of those attempts at subliminal communication. Fruit is good for you therefore our underwear is good for you. In fact, our underwear (just like the fruit) has health benefits.

For a deeper dive into the world of semiotics, there’s the ‘be fruitful and multiply’ stricture which is found in more than one religious or cultural orientation and is hard to dismiss once considered.

There is no reason to add fruit to the images other than to suggest benefits from nature and fertility (or fruitfulness). They’re not selling fruit and these ones are not particularly high in zinc. If all you’re looking for is colour, why not vegetables or puppies?

The claims

I don’t have time to review all of the claims but I’ll highlight a few. My biggest problem with the claims is that there are no citations or links to studies, i.e., the research. So, something like this becomes hard to assess,

Most women’s underwear are made with chemical-based, synthetic fibers that lead to yeast and UTI [urinary tract infection] infections, odor, and discomfort. They’ve also been proven to disrupt human hormones, have been linked to cancer, pollute the planet aggressively, and stay in landfills far too long.

There’s more than one path to a UTI and/or odor and/or discomfort but I can see where fabrics that don’t breathe can exacerbate or cause problems of that nature. I have a little more difficulty with the list that follows. I’d like to see the research on underpants disrupting human hormones. Is this strictly a problem for women or could men also be affected? (If you should know, please leave a comment.)

As for ‘linked to cancer’, I’m coming to the conclusion that everything is linked to cancer. Offhand, I’ve been told peanuts, charcoal broiled items (I think it’s the char), and my negative thoughts are all linked to cancer.

One of the last claims in the excerpted section, ‘pollute the planet aggressively’ raises this question.When did underpants become aggressive’?

The final claim seems unexceptional. Our detritus is staying too long in our landfills. Of course, the next question is: how much faster do the Huha underpants degrade in a landfill? That question is not addressed in Kickstarter campaign material.

Talking to someone with more expertise

I contacted Dr. Andrew Maynard, Associate Director at Arizona State University (ASU) School for the Future of Innovation in Society, He has a PhD in physics and longstanding experience in research and evaluation of emerging technologies (for many years he specialized in nanoparticle analysis and aerosol exposure in occupational settings),.

Professor Maynard is a widely recognized expert and public commentator on emerging technologies and their safe and responsible development and use, and has testified before [US] congressional committees on a number of occasions. 

None of this makes him infallible but I trust that he always works with integrity and bases his opinions on the best information at hand. I’ve always found him to be a reliable source of information.

Here’s what he had to say (from an October 25, 2019 email),

I suspect that their claims are pushing things too far – from what I can tell, professionals tend to advise against synthetic underwear because of the potential build up of moisture and bacteria and the lack of breathability, and tend to suggest natural materials – which indicating that natural fibers and good practices should be all most people need. I haven’t seen any evidence for an underwear crisis here, and one concern is that the company is manufacturing a problem which they then claim to solve. That said, I can’t see anything totally egregious in what they are doing. And the zinc presence makes sense in that it prevents bacterial growth/activity within the fabric, thus reducing the chances of odor and infection.

Pharmaceutical grade zinc and research into underwear

I was a little curious about ‘pharmaceutical grade’ zinc as my online searches for a description were unsuccessful. Andrew explained that the term likely means ‘high purity’ zinc suitable for use in medications rather than the zinc found in roofing panels.

After the reference to ‘pharmaceutical grade’ zinc there’s a reference to ‘smartcel sensitive Zinc’. Here’s more from the smartcel sensitive webpage,

smartcel™ sensitive is skin friendly thanks to zinc oxide’s soothing and anti-inflammatory capabilities. This is especially useful for people with sensitive skin or skin conditions such as eczema or neurodermitis. Since zinc is a component of skin building enzymes, it operates directly on the skin. An active exchange between the fiber and the skin occurs when the garment is worn.

Zinc oxide also acts as a shield against harmful UVA and UVB radiation [it’s used in sunscreens], which can damage our skin cells. Depending on the percentage of smartcel™ sensitive used in any garment, it can provide up to 50 SPF.

Further to this, zinc oxide possesses strong antibacterial properties, especially against odour causing bacteria, which helps to make garments stay fresh longer. *

I couldn’t see how zinc helps the pH balance in anyone’s vagina as claimed in the Kickstarter campaign and smartcel, on its ‘sensitive’ webpage, doesn’t make that claim but I found an answer in an April 4, 2017 Q&A (question and answer) interview by Jocelyn Cavallo for Medium,

What women need to know about their vaginal p

Q & A with Dr. Joanna Ellington

A woman’s vagina is a pretty amazing body part. Not only can it be a source of pleasure but it also can help create and bring new life into the world. On top of all that, it has the extraordinary ability to keep itself clean by secreting natural fluids and maintaining a healthy pH to encourage the growth of good bacteria and discourage harmful bacteria from moving in. Despite being so important, many women are never taught the vital role that pH plays in their vaginal health or how to keep it in balance.

We recently interviewed renowned Reproductive Physiologist and inventor of IsoFresh Balancing Vaginal Gel, Dr. Joanna Ellington, to give us the low down on what every woman needs to know about their vaginal pH and how to maintain a healthy level.

What is pH?

Dr. Ellington: PH is a scale of acidity and alkalinity. The measurements range from 0 to 14: a pH lower than 7 is acidic and a pH higher than 7 is considered alkaline.

What is the “perfect” pH level for a woman’s vagina?

Dr. E.: For most women of a reproductive age vaginal pH should be 4.5 or less. For post-menopausal women this can go up to about 5. The vagina will naturally be at a high pH right after sex, during your period, after you have a baby or during ovulation (your fertile time).

Are there diet and environmental factors that affect a women’s vaginal pH level?

Dr. E.: Yes, iron zinc and manganese have been found to be critical for lactobacillus (healthy bacteria) to function. Many women don’t eat well and should supplement these, especially if they are vegetarian. Additionally, many vegetarians have low estrogen because they do not eat the animal fats that help make our sex steroids. Without estrogen, vaginal pH and bacterial imbalance can occur. It is important that women on these diets ensure good fat intake from other sources, and have estrogen and testosterone and iron levels checked each year.

Do clothing and underwear affect vaginal pH?

Dr. E.: Yes, tight clothing and thong underwear [emphasis mine] have been shown in studies to decrease populations of healthy vaginal bacteria and cause pH changes in the vagina. Even if you wear these sometimes, it is important for your vaginal ecosystem that loose clothing or skirts be worn some too.

Yes, Dr. Ellington has the IsoFresh Balancing Vaginal Gel and whether that’s a good product should be researched but all of the information in the excerpt accords with what I’ve heard over the years and fits in nicely with what Andrew said, zinc in underwear could be useful for its antimicrobial properties. Also, note the reference to ‘thong underwear’ as a possible source of difficulty and note that Huha is offering thong and very high cut underwear.

Of course, your underwear may already have zinc in it as this research suggests (thank you, Andrew, for the reference),

Exposure of women to trace elements through the skin by direct contact with underwear clothing by Thao Nguyen & Mahmoud A. Saleh. Journal of Environmental Science and Health, Part A Toxic/Hazardous Substances and Environmental Engineering Volume 52, 2017 – Issue 1 Pages 1-6 DOI: https://doi.org/10.1080/10934529.2016.1221212 Published online: 09 Sep 2016

This paper is behind a paywall but I have access through a membership in the Canadian Academy of Independent Scholars. So, here’s the part I found interesting,

… The main chemical pollutants present in textiles are dyes containing carcinogenic amines, metals, pentachlorophenol, chlorine bleaching, halogen carriers, free formaldehyde, biocides, fire retardants and softeners.[1] Metals are also found in textile products and clothing are used for many purposes: Co [cobalt], Cu [copper], Cr [chromium] and Pb [lead] are used as metal complex dyes, Cr as pigments mordant, Sn as catalyst in synthetic fabrics and as synergists of flame retardants,Ag [silver] as antimicrobials and Ti [titanium] and Zn [zinc] as water repellents and odor preventive agents.[2–5] When present in textile materials, the toxic elements mentioned above represent not only a major environmental problem in the textile industry but also they may impose potential danger to human health by absorption through the skin.[6,7] [emphasis mine] Chronic exposure to low levels of toxic elements has been associated with a number of adverse human health effects.[8–11] Also exposure to high concentration of elements which are considered as essential for humans such as Cu, Co, Fe [iron], Mn [manganese] or Zn among others, can also be harmful.[12] [emphasis mine] Co, Cr, Cu and Ni [nitrogen] are skin sensitizers,[13,14] which may lead to contact dermatitis, also Cr can lead to liver damage, pulmonary congestion and cancer.[15] [emphasis mine] The purpose of the present study was to determine the concentrations of a number of elements in various skin-contact clothes. For risk estimations, the determination of the extractable amounts of heavy metals is of importance, since they reflect their possible impact on human health. [p. 2 PDF]

So, there’s the link to cancer. Maybe.

Are zinc-infused undies a good idea?

It could go either way. (For specifics about the conclusions reached in the study, scroll down to the Ooops! subheading.) I like the idea of using sustainable Eucalyptus-based material (TencelL) for the underwear as I have heard that cotton isn’t sustainably cultivated. As for claims regarding the product’s environmental friendliness, it’s based on wood, specifically, cellulose, which Canadian researchers have been experimenting with at the nanoscale* and they certainly have been touting nanocellulose as environmentally friendly. Tencel’s sustainability page lists a number of environmental certifications from the European Union, Belgium, and the US.

*Somewhere in the Kickstarter campaign material, there’s a reference to nanofibrils and I’m guessing those nanofibrils are Tencel’s wood fibers at the nanoscale. As well, I’m guessing that smartcel’s fabric contains zinc oxide nanoparticles.

Whether or not you need more zinc is something you need to determine for yourself. Finding out if the pH balance in your vagina is within a healthy range might be a good way to start. It would also be nice to know how much zinc is in the underwear and whether it’s being used antimicrobial properties and/or as a source for one of minerals necessary for your health.

How the Kickstarter campaign is going

At the time of this posting, they’ve reached a little over $24,000 with six days left. The goal was $10,000. Sadly, there are no questions in the FAQ (frequently asked questions).

Reading tips

It’s exhausting trying to track down authenticity. In this case, there were health and environmental claims but I do have a few suggestions.

  1. Look at the imagery critically and try to ignore the hyperbole.
  2. How specific are the claims? e.g., How much zinc is there in the underpants?
  3. Who are their experts and how trustworthy are the agencies/companies mentioned?
  4. If research is cited, are the publishers reputable and is the journal reputable?
  5. Does it make sense given your own experience?
  6. What are the consequences if you make a mistake?

Overblown claims and vague intimations of disease are not usually good signs. Conversely, someone with great credential may not be trustworthy which is why I usually try to find more than one source for confirmation. The person behind this campaign and the Huha company is Alexa Suter. She’s based in Vancouver, Canada and seems to have spent most of her time as a writer and social media and video producer with a few forays into sales and real estate. I wonder if she’s modeling herself and her current lifestyle entrepreneurial effort on Gwyneth Paltrow and her lifestyle company, Goop.

Huha underwear may fulfill its claims or it may be just another pair of underwear or it may be unhealthy. As for the environmentally friendly claims, let’s hope that the case. On a personal level, I’m more hopeful about that.

Regardless, the underwear is not cheap. The smallest pledge that will get your underwear (a three-pack) is $65 CAD.

Ooops! ETA: November 8, 2019:

I forgot to include the conclusion the researchers arrived at and some details on how they arrived at those conclusions. First, they tested 120 pairs of underpants in all sorts of colours and made in different parts of the world.

Second, some underpants showed excessive levels of metals. Cotton was the most likely material to show excess although nylon and polyester can also be problematic. To put this into proportion and with reference to zinc, “Zn exceeded the limit in 4% of the tested samples
and was found mostly in samples manufactured in China.” [p. 6 PDF] Finally, dark colours tested for higher levels of metals than light colours.

While it doesn’t mention underpants as such, there’s a November 8, 2019 article ‘Five things everyone with a vagina should know‘ by Paula McGrath for BBC news online. McGrath’s health expert is Dr. Jen Gunter, a physician whose specialties are obstetrics, gynaecology, and pain.