Category Archives: beauty and cosmetics

BSB Nanotechnology, silicon dioxide nanoparticles (SiO2), and Dow

Silicon dioxide (a form of silicon) is more commonly known as silica. There are problems with our use of *silica and so it was interesting to see this announcement (from a September 21, 2022 Dow news release on csiwire.com),

MIDLAND, Mich., September 21, 2022 /CSRwire/ – Dow (NYSE: Dow) announced a new engagement with BSB Nanotechnology Joint Stock Company, the world’s first producer of premium rice husk-based specialty silica. Rice husk, a renewable resource produced as a waste product of rice milling, is used for a plethora of diverse applications in the personal care market. This engagement helps accelerate Dow’s commitment towards a bio-based offering. The newly added ingredient – sold under the Dow trademark EcoSmooth™ Rice Husk Cosmetic Powder – delivers optical benefits and a unique sensorial experience for consumers in skin care, hair care and color cosmetic applications.

“Dow’s partnership with BSB Nanotechnology shines a light on how we continue to deliver on our commitment to transition towards a circular and low-carbon personal care offering while fostering valuable relationships with industry trailblazers,” said Isabel Almiro do Vale, global marketing and strategy director for Dow Personal Care. “This partnership is another significant milestone allowing Dow to expand its portfolio of products that enable eco-conscious claims, prioritizing solutions that deliver high-quality, benefits backed by science.”

The product of choice for the eco-conscious consumer, the EcoSmooth™ Rice Husk Cosmetic Powder is the exclusive ingredient to make its debut between the two parties. Compiled from non-GMO natural sources, this silica powder is upcycled from rice husk, a by-product from agriculture. It delivers a smooth feel combined with optical benefits like blurring imperfections and mattifying skin.

“This agreement signifies not only the first step towards a collaboration between Dow and BSB in the personal care sector but has also opened new pathways to other business sectors within Dow where BSB’s bio-based rice husk silica can offer sustainability and multifunctionality,” said Hung Nguyen, CEO of BSB. “BSB will continue to create more innovative and green solutions for the world and offer these additives through global partners like Dow.”

About Dow Personal Care Solutions

Dow Personal Care offers unique, innovative ingredients that empower customers around the world to create products with exceptional performance and exciting benefits that consumers can trust and believe in. Consumers that seek the confidence of a healthy appearance can see and feel the difference in our products through their lustrous hair or radiant and protected skin. We leverage our understanding of customer needs, deep market knowledge and technical expertise—combined with one of the broadest portfolios of technologies—to deliver personal care solutions with outstanding performance that are safe for people and the planet. We foster these innovations on global and local levels to meet the needs of diverse consumers through business centers, research and development (R&D), manufacturing plants and customer applications centers around the world. Please visit for more information.

About Dow

Dow (NYSE: DOW) combines global breadth; asset integration and scale; focused innovation and materials science expertise; leading business positions; and environmental, social and governance (ESG) leadership to achieve profitable growth and deliver a sustainable future. The Company’s ambition is to become the most innovative, customer centric, inclusive and sustainable materials science company in the world. Dow’s portfolio of plastics, industrial intermediates, coatings and silicones businesses delivers a broad range of differentiated, science-based products and solutions for its customers in high-growth market segments, such as packaging, infrastructure, mobility and consumer applications. Dow operates 104 manufacturing sites in 31 countries and employs approximately 35,700 people. Dow delivered sales of approximately $55 billion in 2021. References to Dow or the Company mean Dow Inc. and its subsidiaries. For more information, please visit www.dow.com or follow @DowNewsroom on Twitter.

About BSB Nanotechnology

BSB Nanotechnology Joint Stock Company, an established multi-faceted business, forayed into the rice world through the formulation of rice-based milk, a widely popular beverage in Vietnam. Strategically located in the Mekong Delta, the rice basket of Vietnam, BSB Nanotech taps into the country’s position as the 5th largest rice producer to access the main ingredient to its healthy beverage product. While feeding this nutritious gift of nature to the people of Vietnam, BSB Nanotech was presented with large amounts of rice husk, a waste product of rice milling. Building upon the business principle of reducing waste by reuse, BSB Nanotech has embarked on a journey to discover and create the value that rice husk could offer through its range of premium rice husk silica under the brand Biosilico. For more information, visit www.biosilico.vn .

I’m quite taken with BSB Nanotechnology’s Biosilico About page,

THE JOURNEY FROM ASH TO CASH

BSB Nanotechnology Joint Stock Company, an established multi-faceted business, forayed into the rice world through the formulation of rice-based milk, a widely popular beverage in Vietnam. Strategically located in the Mekong Delta, the rice basket of Vietnam, BSB Nanotech taps into the country’s  position as the 5th largest rice producer to access the main ingredient to its healthy beverage product. While feeding this nutritious gift of nature to the people of Vietnam, BSB Nanotech was presented with large amounts of rice husk, a waste product of rice milling. Building upon the business principle of reducing waste by reuse, BSB Nanotech has embarked on a journey to discover the value that rice husk could offer.

In the attempt to derive by-products from rice husk, BSB Nanotech learns that the most significant value held within rice husk ash is the high content of naturally present silica. Currently, sand and quartz are the only other naturally occurring silica sources. However, extracting silica from sand and quartz not only causes health hazards, but sand mining by itself presents a huge ecological and sociological problem. The utilization of rice husk ash to produce nanoporous silica is a positive step towards both a bio-based and circular economy, as ultrafine silica/nanosilica can be manufactured from this renewable resource and agricultural waste.

After 4 years of extensive research and development, a highly dedicated team of researchers of BSB Nanotech has successfully harnessed amorphous silica in its highest purity and quality from this waste material using a unique and patented technology. A new bio-based nanoporous silica under the BIOSILICO brand is now commercially available and can be customized to suit an array of applications.

OUR PROMISE TODAY FOR A BETTER TOMORROW

Today, BSB Nanotech is recognized as the world’s first producer of rice husk based nanoporous silica on a commercial scale. We are currently working with several global partners to expand the range of BIOSILICO’s applications from the Paints and Coatings to Rubber additives and Cosmetics industries.

To ensure that our products are delivered with its promised quality and committed schedule, BSB Nanotech undertook rigorous training and auditing to refine its operation, and production process and documentation to achieve the ISO [International Standards Organisation] QMS certification in 2020.

The company has embarked on a roadmap to become a global producer and developer of rice husk based nanoporous silica in both production volume and diverse applications.

Untitled.png

Maybe one of these days we’ll see BSB Nanotechnology at the annual Zero Waste Conference held here in Vancouver (Canada) during the autumn.

*See my July 10, 2014 posting scroll down [about 10%] to the University of California at Riverside news release for difficulties of working with silicon at the nanoscale, then scroll down about 40% to the discussion of Sand Wars, a documentary about how our appetite for silica (silicon dioxide) is depleting our beaches of sand.*

Tattoo yourself painlessly

This is all at the microscale (for those who don’t know what micro means in this context, it’s one-millionth; specifically, the needles are measured in miilionths of a meter).

Caption: A magnified view of a microneedle patch with green tattoo ink. Credit: Georgia Tech

From a September 14, 2022 Georgia Institute of Technology (Georgia Tech) news release (also on EurekAlert),

Instead of sitting in a tattoo chair for hours enduring painful punctures, imagine getting tattooed by a skin patch containing microscopic needles. Researchers at the Georgia Institute of Technology have developed low-cost, painless, and bloodless tattoos that can be self-administered and have many applications, from medical alerts to tracking neutered animals to cosmetics.

“We’ve miniaturized the needle so that it’s painless, but still effectively deposits tattoo ink in the skin,” said Mark Prausnitz, principal investigator on the paper. “This could be a way not only to make medical tattoos more accessible, but also to create new opportunities for cosmetic tattoos because of the ease of administration.”

Prausnitz, Regents’ Professor and J. Erskine Love Jr. Chair in the School of Chemical and Biomolecular Engineering, presented the research in the journal iScience, with former Georgia Tech postdoctoral fellow Song Li as co-author.

Tattoos are used in medicine to cover up scars, guide repeated cancer radiation treatments, or restore nipples after breast surgery. Tattoos also can be used instead of bracelets as medical alerts to communicate serious medical conditions such as diabetes, epilepsy, or allergies.

Various cosmetic products using microneedles are already on the market — mostly for anti-aging — but developing microneedle technology for tattoos is new. Prausnitz, a veteran in this area, has studied microneedle patches for years to painlessly administer drugs and vaccines to the skin without the need for hypodermic needles.

“We saw this as an opportunity to leverage our work on microneedle technology to make tattoos more accessible,” Prausnitz said. “While some people are willing to accept the pain and time required for a tattoo, we thought others might prefer a tattoo that is simply pressed onto the skin and does not hurt.” 

Transforming Tattooing

Tattoos typically use large needles to puncture repeatedly into the skin to get a good image, a time-consuming and painful process. The Georgia Tech team has developed microneedles that are smaller than a grain of sand and are made of tattoo ink encased in a dissolvable matrix.

“Because the microneedles are made of tattoo ink, they deposit the ink in the skin very efficiently,” said Li, the lead author of the study.

In this way, the microneedles can be pressed into the skin just once and then dissolve, leaving the ink in the skin after a few minutes without bleeding.  

Tattooing Technique

Although most microneedle patches for pharmaceuticals or cosmetics have dozens or hundreds of microneedles arranged in a square or circle, microneedle patch tattoos imprint a design that can include letters, numbers, symbols, and images. By arranging the microneedles in a specific pattern, each microneedle acts like a pixel to create a tattoo image in any shape or pattern.

The researchers start with a mold containing microneedles in a pattern that forms an image. They fill the microneedles in the mold with tattoo ink and add a patch backing for convenient handling. The resulting patch is then applied to the skin for a few minutes, during which time the microneedles dissolve and release the tattoo ink. Tattoo inks of various colors can be incorporated into the microneedles, including black-light ink that can only be seen when illuminated with ultraviolet light.

Prausnitz’s lab has been researching microneedles for vaccine delivery for years and realized they could be equally applicable to tattoos. With support from the Alliance for Contraception in Cats and Dogs, Prausnitz’s team started working on tattoos to identify spayed and neutered pets, but then realized the technology could be effective for people, too.

The tattoos were also designed with privacy in mind. The researchers even created patches sensitive to environmental factors such as light or temperature changes, where the tattoo will only appear with ultraviolet light or higher temperatures. This provides patients with privacy, revealing the tattoo only when desired.

The study showed that the tattoos could last for at least a year and are likely to be permanent, which also makes them viable cosmetic options for people who want an aesthetic tattoo without risk of infection or the pain associated with traditional tattoos. Microneedle tattoos could alternatively be loaded with temporary tattoo ink to address short-term needs in medicine and cosmetics.

Microneedle patch tattoos can also be used to encode information in the skin of animals. Rather than clipping the ear or applying an ear tag to animals to indicate sterilization status, a painless and discreet tattoo can be applied instead.

“The goal isn’t to replace all tattoos, which are often works of beauty created by tattoo artists,” Prausnitz said. “Our goal is to create new opportunities for patients, pets, and people who want a painless tattoo that can be easily administered.”

Prausnitz has co-founded a company called Micron Biomedical that is developing microneedle patch technology, bringing it further into clinical trials, commercializing it, and ultimately making it available to patients. 

Prausnitz and several other Georgia Tech researchers are inventors of the microneedle patch technology used in this study and have ownership interest in Micron Biomedical. They are entitled to royalties derived from Micron Biomedical’s future sales of products related to the research. These potential conflicts of interest have been disclosed and are overseen by Georgia Institute of Technology. 

You can see what they mean when they claim this is not competitive with the work you’ll see from a tattoo artist,

Heart tattoo: microneedle patch (above) and tattoo on skin (below).Credit: Song Li, Georgia Tech

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

Microneedle patch tattoos by Song Li, Youngeun Kim, Jeong Woo Lee, Mark R. Prausnitz. iScience DOI:https://doi.org/10.1016/j.isci.2022.105014 Published: September 14, 2022

This paper is open access.

The company mentioned in the news release, Micron Biomedical can be found here.

Extending a wig’s life with a nanocomposite

A June 13, 2022 American Chemical Society (ACS) news release (also on EurekAlert) announces a nanocomposite that could make wigs last longer,

For some people, wigs are a fun and colorful fashion accessory, but for those with hair loss from alopecia or other conditions, they can provide a real sense of normalcy and boost self-confidence. Whether made from human or synthetic strands, however, most hairpieces lose their luster after being worn day after day. Now, researchers in ACS Applied Materials & Interfaces report a new way to make wigs more durable and long lasting.

Wigs come in all colors of the rainbow and in every style imaginable. Some cover the whole head, while others are “extensions,” sections of hair that clip onto existing locks to make them look fuller or longer. Hairpieces can be made of real human strands or synthetic materials, but either way, washing, UV exposure from the sun and repeated styling can cause these products to become dry and brittle. To extend the wearable life of wigs, some researchers have spray-coated a layer of graphene oxide on them, whereas other teams have immersed wig hairs in a keratin/halloysite nanocomposite. Because it’s difficult to cover an entire hairpiece with these methods, Guang Yang, Huali Nie and colleagues wanted to see if a nanocomposite applied with a tried-and-true approach for coating surfaces with ultrathin films — known as the Langmuir-Blodgett (LB) technique — could improve coverage and increase durability.

The researchers first developed a keratin and graphene oxide nanocomposite as the coating material. To coat hairs with the LB method, they dipped a few human or synthetic hairs into water in a special apparatus with moveable side barriers. After the nanocomposite was spread on the water’s surface with an atomizer, the barriers were moved inward to compress the film— like the trash compactor that almost crushed the heroes in the movie Star Wars. After 30 minutes, the researchers lifted the hairs out of the water, and as they did so, the film coated the locks.

Compared to the immersion technique, the LB method provided more coverage. In addition, hairs treated with the LB approach sustained less UV damage, were less prone to breakage and could hold more moisture than those that were simply immersed in the nanocomposite. They also dissipated heat better and generated less static electricity when rubbed with a rubber sheet. The researchers say that the method can be scaled up for use by companies that manufacture wigs.

The authors acknowledge funding from the Fundamental Research Funds for the Central Universities, the Shanghai Natural Science Foundation, the Shanghai Pujiang Program, the Natural Science Foundation of Shandong Province, and the Shanghai International Cooperative Project of the Belt and Road.

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

High-Performance Wigs via the Langmuir–Blodgett Deposition of Keratin/Graphene Oxide Nanocomposite by Shan Du, Tiantian He, Huali Nie, and Guang Yang. ACS Appl. Mater. Interfaces 2022, 14, 23, 27233–27241 DOI: https://doi.org/10.1021/acsami.2c05965 Publication Date:June 3, 2022 Copyright © 2022 American Chemical Society

This paper is behind a paywall.

Oxygen-deficient nanotitania (titanium dioxide nanoparticles) for whiter teeth without the damage

A September 8, 2021 news item on phys.org announces research that could make the process of whitening teeth safer,

Most people would like to flash a smile of pearly whites, but over time teeth can become stained by foods, beverages and some medications. Unfortunately, the high levels of hydrogen peroxide in dentists’ bleaching treatments can damage enamel and cause tooth sensitivity and gum irritation. Now, researchers reporting in ACS Applied Materials & Interfaces have developed a gel that, when exposed to near infrared (NIR) light, safely whitens teeth without the burn.

Caption: A new bleaching gel whitened tooth samples by six shades, using a low level of hydrogen peroxide (12%). Credit: Adapted from ACS Applied Materials & Interfaces 2021, DOI: 10.1021/acsami.1c06774

A September 8, 2021Amercian Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, provides more detail,

The growing demand for selfie-ready smiles has made tooth whitening one of the most popular dental procedures. Treatments at a dentist’s office are effective, but they use high-concentration hydrogen peroxide (30–40%). Home bleaching products contain less peroxide (6–12%), but they usually require weeks of treatment and don’t work as well. When a bleaching gel is applied to teeth, hydrogen peroxide and peroxide-derived reactive oxygen species (mainly the hydroxyl radical) degrade pigments in stains. The hydroxyl radical is much better at doing this than hydrogen peroxide itself, so researchers have tried to improve the bleaching capacity of low-concentration hydrogen peroxide by boosting the generation of powerful hydroxyl radicals. Because previous approaches have had limitations, Xingyu Hu, Li Xie, Weidong Tian and colleagues wanted to develop a safe, effective whitening gel containing a catalyst that, when exposed to NIR light, would convert low levels of hydrogen peroxide into abundant hydroxyl radicals.

The researchers made oxygen-deficient titania nanoparticles that catalyzed hydroxyl radical production from hydrogen peroxide. Exposing the nanoparticles to NIR light increased their catalytic activity, allowing them to completely bleach tooth samples stained with orange dye, tea or red dye within 2 hours. Then, the researchers made a gel containing the nanoparticles, a carbomer gel and 12% hydrogen peroxide. They applied it to naturally stained tooth samples and treated them with NIR light for an hour. The gel bleached teeth just as well as a popular tooth whitening gel containing 40% hydrogen peroxide, with less damage to enamel. The nanoparticle system is highly promising for tooth bleaching and could also be extended to other biomedical applications, such as developing antibacterial materials, the researchers say.

The authors acknowledge funding from the National Natural Science Foundation of China, the National Key R&D Program of China and the Key Technologies R&D Program of Sichuan Province.

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

Photothermal-Enhanced Fenton-like Catalytic Activity of Oxygen-Deficient Nanotitania for Efficient and Safe Tooth Whitening by Xingyu Hu, Li Xie, Zhaoyu Xu, Suru Liu, Xinzhi Tan, Ruojing Qian, Ruitao Zhang, Mingyan Jiang, Wenjia Xie, and Weidong Tian. ACS Appl. Mater. Interfaces 2021, 13, 30, 35315–35327 Publication Date: July 22, 2021 DOI: https://doi.org/10.1021/acsami.1c06774 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Cerium-containing nanoparticles in microneedle patches for hair regrowth (a treatment for baldness?)

It’s still being tested but according to an August 11, 2021 news item on ScienceDaily, this is a promising treatment for baldness,

Although some people say that baldness is the “new sexy,” for those losing their hair, it can be distressing. An array of over-the-counter remedies are available, but most of them don’t focus on the primary causes: oxidative stress and insufficient circulation. Now, researchers reporting in ACS Nano have designed a preliminary microneedle patch containing cerium nanoparticles to combat both problems, regrowing hair in a mouse model faster than a leading treatment.

An August 11, 2021 American Chemical Society (ACS) news release (also on EurekAlert) provides more detail (Note: Links have been removed),

The most common hair loss condition is called androgenic alopecia, also known as male- or female- pattern baldness. Hair loss is permanent for people with the condition because there aren’t enough blood vessels surrounding the follicles to deliver nutrients, cytokines and other essential molecules. In addition, an accumulation of reactive oxygen species in the scalp can trigger the untimely death of the cells that form and grow new hair. Previously, Fangyuan Li, Jianqing Gao and colleagues determined that cerium-containing nanoparticles can mimic enzymes that remove excess reactive oxygen species, which reduced oxidative stress in liver injuries, wounds and Alzheimer’s disease. However, these nanoparticles cannot cross the outermost layer of skin. So, the researchers wanted to design a minimally invasive way to deliver cerium-containing nanoparticles near hair roots deep under the skin to promote hair regrowth.

As a first step, the researchers coated cerium nanoparticles with a biodegradable polyethylene glycol-lipid compound. Then they made the dissolvable microneedle patch by pouring a mixture of hyaluronic acid — a substance that is naturally abundant in human skin — and cerium-containing nanoparticles into a mold. The team tested control patches and the cerium-containing ones on male mice with bald spots formed by a hair removal cream. Both applications stimulated the formation of new blood vessels around the mice’s hair follicles. However, those treated with the nanoparticle patch showed faster signs of hair undergoing a transition in the root, such as earlier skin pigmentation and higher levels of a compound found only at the onset of new hair development. These mice also had fewer oxidative stress compounds in their skin. Finally, the researchers found that the cerium-containing microneedle patches resulted in faster mouse hair regrowth with similar coverage, density and diameter compared with a leading topical treatment and could be applied less frequently. Microneedle patches that introduce cerium nanoparticles into the skin are a promising strategy to reverse balding for androgenetic alopecia patients, the researchers say.

The authors acknowledge funding from the Ten-thousand Talents Program of Zhejiang Province, National Key R&D Program of China, National Natural Science Foundation of China, One Belt and One Road International Cooperation Project from the Key Research and Development Program of Zhejiang Province, Fundamental Research Funds for the Central Universities and Zhejiang Provincial Natural Science Foundation of China.

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

Ceria Nanozyme-Integrated Microneedles Reshape the Perifollicular Microenvironment for Androgenetic Alopecia Treatment by Anran Yuan, Fan Xia, Qiong Bian, Haibin Wu, Yueting Gu, Tao Wang, Ruxuan Wang, Lingling Huang, Qiaoling Huang, Yuefeng Rao, Daishun Ling, Fangyuan Li, and Jianqing Gao. ACS Nano 2021, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsnano.1c05272 Publication Date:July 19, 2021 © 2021 American Chemical Society

This paper is behind a paywall.

Precision skincare

An inkjet printer for your skin—it’s an idea I’m not sure I’m ready for. Still, I’m not the target market for the product being described in Rachel Kim Raczka’s June 2, 2021 article for Fast Company (Note: Links have been removed),

… I’ve had broken capillaries, patchy spots, and enlarged pores most of my adult life. And after I turned 30, I developed a glorious strip of melasma (a “sun mustache”) across my upper lip. The delicate balance of maintaining my “good” texture—skin that looks like skin—while disguising my “bad” texture is a constant push and pull. Still, I continue to fall victim to “no makeup” makeup, the frustratingly contradictory trend that will never die. A white whale that $599 high-tech beauty printer Opte hopes to fill.

Weirdly enough, “printer” is a fair representation of what Opte is. The size and shape of an electric razor, Opte’s Precision Wand’s tiny computer claims to detect and camouflage hyperpigmentation with a series of gentle swipes. The product deposits extremely small blends of white, yellow, and red pigments to hide discoloration using a blue LED and a hypersensitive camera that scans 200 photos per second. Opte then relies on an algorithm to apply color—housed in replaceable serum cartridges, delivered through 120 thermal inkjet nozzles—only onto contrasting patches of melanin via what CEO Matt Petersen calls “the world’s smallest inkjet printer.” 

Opte is a 15-year, 500,000-R&D-hour project developed under P&G Ventures, officially launched in 2020. While targeting hyperpigmentation was an end goal, the broader mission looked at focusing on “precision skincare.” …

… You start by dropping the included 11-ingredient serum cartridge into the pod; the $129 cartridges and refills come in three shades that the company says cover 98% of skin tones and last 90 days. The handheld device very loudly refills itself and displays instructions on a tiny screen on its handle. …

… While I can’t rely on the Opte to hide a blemish or dark circles—I’ll still need concealer to achieve that level of coverage—I can’t quite describe the “glowiness” using this gadget generates. With more use, I’ve come to retrain my brain to expect Opte to work more like an eraser than a crayon; it’s skincare, not makeup. My skin looks healthier and brighter but still, without a doubt, like my skin. 

There’s more discussion of how this product works in Raczka’s June 2, 2021 article and you can find the Opte website here. I have no idea if they ship this product outside the US or what that might cost.

Sunscreens 2020 and the Environmental Working Group (EWG)

There must be some sweet satisfaction or perhaps it’s better described as relief for the Environmental Working Group (EWG) now that sunscreens with metallic (zinc oxide and/or titanium dioxide) nanoparticles are gaining wide acceptance. (More about the history and politics EWG and metallic nanoparticles at the end of this posting.)

This acceptance has happened alongside growing concerns about oxybenzone, a sunscreen ingredient that EWG has long warned against. Oxybenzone has been banned from use in Hawaii due to environmental concerns (see my July 6, 2018 posting; scroll down about 40% of the way for specifics about Hawaii). Also, it is one of the common sunscreen ingredients for which the US Food and Drug Administration (FDA) is completing a safety review.

Today, zinc oxide and titanium dioxide metallic nanoparticles are being called minerals, as in, “mineral-based” sunscreens. They are categorized as physical sunscreens as opposed to chemical sunscreens.

I believe the most recent sunscreen posting here was my 2018 update (uly 6, 2018 posting) so the topic is overdue for some attention here. From a May 21, 2020 EWG news release (received via email),

As states reopen and Americans leave their homes to venture outside, it’s important for them to remember to protect their skin from the sun’s harmful rays. Today the Environmental Working Group released its 14th annual Guide to Sunscreens.  

This year researchers rated the safety and efficacy of more than 1,300 SPF products – including sunscreens, moisturizers and lip balms – and found that only 25 percent offer adequate protection and do not contain worrisome ingredients such as oxybenzone, a potential hormone-disrupting chemical that is readily absorbed by the body.

Despite a delay in finalizing rules that would make all sunscreens on U.S. store shelves safer, the Food and Drug Administration, the agency that governs sunscreen safety, is completing tests that highlight concerns with common sunscreen ingredients. Last year, the agency published two studies showing that, with just a single application, six commonly used chemical active ingredients, including oxybenzone, are readily absorbed through the skin and could be detected in our bodies at levels that could cause harm.

“It’s quite concerning,” said Nneka Leiba, EWG’s vice president of Healthy Living science. “Those studies don’t prove whether the sunscreens are unsafe, but they do highlight problems with how these products are regulated.”

“EWG has been advocating for the FDA to review these chemical ingredients for 14 years,” Leiba said. “We slather these ingredients on our skin, but these chemicals haven’t been adequately tested. This is just one example of the backward nature of product regulation in the U.S.”

Oxybenzone remains a commonly used active ingredient, found in more than 40 percent of the non-mineral sunscreens in this year’s guide. Oxybenzone is allergenic and a potential endocrine disruptor, and has been detected in human breast milk, amniotic fluid, urine and blood.

According to EWG’s assessment, fewer than half of the products in this year’s guide contain active ingredients that the FDA has proposed are safe and effective.

“Based on the best current science and toxicology data, we continue to recommend sunscreens with the mineral active ingredients zinc dioxide and titanium dioxide, because they are the only two ingredients the FDA recognized as safe or effective in their proposed draft rules,” said Carla Burns, an EWG research and database analyst who manages the updates to the sunscreen guide.

Most people select sunscreen products based on their SPF, or sunburn protection factor, and mistakenly assume that bigger numbers offer better protection. According to the FDA, higher SPF values have not been shown to provide additional clinical benefit and may give users a false sense of protection. This may lead to overexposure to UVA rays that increase the risk of long-term skin damage and cancer. The FDA has proposed limiting SPF claims to 60+.

EWG continues to hone our recommendations by strengthening the criteria for assessing sunscreens, which are based on the latest findings in the scientific literature and commissioned tests of sunscreen product efficacy. This year EWG made changes to our methodology in order to strengthen our requirement that products provide the highest level of UVA protection.

“Our understanding of the dangers associated with UVA exposure is increasing, and they are of great concern,” said Burns. “Sunburn during early life, especially childhood, is very dangerous and a risk factor for all skin cancers, but especially melanoma. Babies and young children are especially vulnerable to sun damage. Just a few blistering sunburns early in life can double a person’s risk of developing melanoma later in life.”

EWG researchers found 180 sunscreens that meet our criteria for safety and efficacy and would likely meet the proposed FDA standards. Even the biggest brands now provide mineral options for consumers.  

Even for Americans continuing to follow stay-at-home orders, wearing an SPF product may still be important. If you’re sitting by a window, UVA and UVB rays can penetrate the glass.  

It is important to remember that sunscreen is only one part of a sun safety routine. People should also protect their skin by covering up with clothing, hats and sunglasses. And sunscreen must be reapplied at least every two hours to stay effective.

EWG’s Guide to Sunscreens helps consumers find products that get high ratings for providing adequate broad-spectrum protection and that are made with ingredients that pose fewer health concerns.

The new guide also includes lists of:

Here are more quick tips for choosing better sunscreens:

  • Check your products in EWG’s sunscreen database and avoid those with harmful ingredients.
  • Avoid products with oxybenzone. This chemical penetrates the skin, gets into the bloodstream and can affect normal hormone activities.
  • Steer clear of products with SPF higher than 50+. High SPF values do not necessarily provide increased UVA protection and may fool you into thinking you are safe from sun damage.
  • Avoid sprays. These popular products pose inhalation concerns, and they may not provide a thick and uniform coating on the skin.
  • Stay away from retinyl palmitate. Government studies link the use of retinyl palmitate, a form of vitamin A, to the formation of skin tumors and lesions when it is applied to sun-exposed skin.
  • Avoid intense sun exposure during the peak hours of 10 a.m. to 4 p.m.

Shoppers on the go can download EWG’s Healthy Living app to get ratings and safety information on sunscreens and other personal care products. Also be sure to check out EWG’s sunscreen label decoder.

One caveat, these EWG-recommended products might not be found in Canadian stores or your favourite product may not have been reviewed for inclusion, as a product to be sought out or avoided, in their database. For example, I use a sunscreen that isn’t listed in the database, although at least a few other of the company’s sunscreen products are. On the plus side, my sunscreen doesn’t include oxybenzone or retinyl palmitate as ingredients.

To sum up the situation with sunscreens containing metallic nanoparticles (minerals), they are considered to be relatively safe but should new research emerge that designation could change. In effect, all we can do is our best with the information at hand.

History and politics of metallic nanoparticles in sunscreens

In 2009 it was a bit of a shock when the EWG released a report recommending the use of sunscreens with metallic nanoparticles in the list of ingredients. From my July 9, 2009 posting,

The EWG (Environmental Working Group) is, according to Maynard [as of 20202: Dr. Andrew Maynard is a scientist and author, Associate Director of Faculty in the ASU {Arizona State University} School for the Future of Innovation in Society, also the director of the ASU Risk Innovation Lab, and leader of the Risk Innovation Nexus], not usually friendly to industry and they had this to say about their own predisposition prior to reviewing the data (from EWG),

When we began our sunscreen investigation at the Environmental Working Group, our researchers thought we would ultimately recommend against micronized and nano-sized zinc oxide and titanium dioxide sunscreens. After all, no one has taken a more expansive and critical look than EWG at the use of nanoparticles in cosmetics and sunscreens, including the lack of definitive safety data and consumer information on these common new ingredients, and few substances more dramatically highlight gaps in our system of public health protections than the raw materials used in the burgeoning field of nanotechnology. But many months and nearly 400 peer-reviewed studies later, we find ourselves drawing a different conclusion, and recommending some sunscreens that may contain nano-sized ingredients.

My understanding is that after this report, the EWG was somewhat ostracized by collegial organizations. Friends of the Earth (FoE) and the ETC Group both of which issued reports that were published after the EWG report and were highly critical of ‘nano sunscreens’.

The ETC Group did not continue its anti nanosunscreen campaign for long (I saw only one report) but FoE (in particular the Australian arm of the organization) more than made up for that withdrawal and to sad effect. My February 9, 2012 post title was this: Unintended consequences: Australians not using sunscreens to avoid nanoparticles?

An Australian government survey found that 13% of Australians were not using any sunscreen due to fears about nanoparticles. In a country with the highest incidence of skin cancer in the world and, which spent untold millions over decades getting people to cover up in the sun, it was devastating news.

FoE immediately withdrew all their anti nanosunscreen materials in Australia from circulation while firing broadsides at the government. The organization’s focus on sunscreens with metallic nanoparticles has diminished since 2012.

Research

I have difficulty trusting materials from FoE and you can see why here in this July 26, 2011 posting (Misunderstanding the data or a failure to research? Georgia Straight article about nanoparticles). In it, I analyze Alex Roslin’s profoundly problematic article about metallic nanoparticles and other engineered nanoparticles. All of Roslin’s article was based on research and materials produced by FoE which misrepresented some of the research. Roslin would have realized that if he had bothered to do any research for himself.

EWG impressed me mightily with their refusal to set aside or dismiss the research disputing their initial assumption that metallic nanoparticles in sunscreens were hazardous. (BTW, there is one instance where metallic nanoparticles in sunscreens are of concern. My October 13, 2013 posting about anatase and rutile forms of titanium dioxide at the nanoscale features research on that issue.)

EWG’s Wikipedia entry

Whoever and however many are maintaining this page, they don’t like EWG at all,

The accuracy of EWG reports and statements have been criticized, as has its funding by the organic food industry[2][3][4][5] Its warnings have been labeled “alarmist”, “scaremongering” and “misleading”.[6][7][8] Despite the questionable status of its work, EWG has been influential.[9]

This is the third paragraph in the Introduction. At its very best, the information is neutral, otherwise, it’s much like that third paragraph.

Even John D. Rockeller’s entry is more flattering and he was known as the ‘most hated man in America’ as this show description on the Public Broadcasting Service (PBS) website makes clear,

American Experience

The Rockefellers Chapter One

Clip: Season 13 Episode 1 | 9m 37s

John D. Rockefeller was the world’s first billionaire and the most hated man in America. Watch the epic story of the man who monopolized oil.

Fun in the sun

Have fun in the sun this summer. There’s EWG’s sunscreen database, the tips listed in the news release, and EWG also has a webpage where they describe their methodology for how they assess sunscreens. It gets a little technical (for me anyway) but it should answer any further safety questions you might have after reading this post.

It may require a bit of ingenuity given the concerns over COVID-19 but I’m constantly amazed at the inventiveness with which so many people have met this pandemic. (This June 15, 2020 Canadian Broadcasting Corporation article by Sheena Goodyear features a family that created a machine that won the 2020 Rube Goldberg Bar of Soap Video challenge. The article includes an embedded video of the winning machine in action.)

Replacing human tissue with nanostructured rubber-like material?

The scientists started out with an idea for creating a bone-like material)and ended up with something completely different. A March 16, 2020 news item on ScienceDaily announces news about a new material that could be used to replace human tissue,

Researchers from Chalmers University of Technology, Sweden, have created a new, rubber-like material with a unique set of properties, which could act as a replacement for human tissue in medical procedures. The material has the potential to make a big difference to many people’s lives. The research was recently published in the highly regarded scientific journal ACS Nano.

In the development of medical technology products, there is a great demand for new naturalistic materials suitable for integration with the body. Introducing materials into the body comes with many risks, such as serious infections, among other things. Many of the substances used today, such as Botox, are very toxic. There is a need for new, more adaptable materials.

In the new study, the Chalmers researchers developed a material consisting solely of components that have already been shown to work well in the body.

A March 17, 2020 Chalmers University of Technology press release (also on EurekAlert but published on March 16, 2020), which originated the news item, describes the scientists’ surprising discovery and how they shifted their focus,

The foundation of the material is the same as plexiglass, a material which is common in medical technology applications. Through redesigning its makeup, and through a process called nanostructuring, they gave the newly patented material a unique combination of properties. The researchers’ initial intention was to produce a hard bone-like material, but they were met with surprising results.

“We were really surprised that the material turned to be very soft, flexible and extremely elastic. It would not work as a bone replacement material, we concluded. But the new and unexpected properties made our discovery just as exciting,” says Anand Kumar Rajasekharan, PhD in Materials Science and one of the researchers behind the study.

The results showed that the new rubber-like material may be appropriate for many applications which require an uncommon combination of properties – high elasticity, easy processability, and suitability for medical uses.

“The first application we are looking at now is urinary catheters. The material can be constructed in such a way that prevents bacteria from growing on the surface, meaning it is very well suited for medical uses,” says Martin Andersson, research leader for the study and Professor of Chemistry at Chalmers.

The structure of the new nano-rubber material allows its surface to be treated so that it becomes antibacterial, in a natural, non-toxic way. This is achieved by sticking antimicrobial peptides – small proteins which are part of our innate immune system – onto its surface. This can help reduce the need for antibiotics, an important contribution to the fight against growing antibiotic resistance.

Because the new material can be injected and inserted via keyhole surgery, it can also help reduce the need for drastic surgery and operations to rebuild parts of the body. The material can be injected via a standard cannula as a viscous fluid, so that it forms its own elastic structures within the body. Or, the material can also be 3D printed into specific structures as required.

“There are many diseases where the cartilage breaks down and friction results between bones, causing great pain for the affected person. This material could potentially act as a replacement in those cases,” Martin Andersson continues.

A further advantage of the material is that it contains three-dimensionally ordered nanopores. This means it can be loaded with medicine, for various therapeutic purposes such as improving healing and reducing inflammation. This allows for localised treatment, avoiding, for example, having to treat the entire body with drugs, something that could help reduce problems associated with side effects. Since it is non-toxic, it also works well as a filler – the researchers see plastic surgery therefore as another very interesting potential area of application for the new material.

“I am now working full time with our newly founded company, Amferia, to get the research out to industry. I have been pleased to see a lot of real interest in our material. It’s promising in terms of achieving our goal, which is to provide real societal benefit,” Anand concludes.

The path of the research to societal benefit and commercialisation, through start-up company Amferia and Chalmers Ventures

In order for the discovery of the new material to be useful and commercialised, the researchers patented their innovation before the study was published. The patent is owned by start-up company Amferia, which was founded by Martin Andersson and Anand Kumar Rajasekharan, two of the researchers behind the study, as well as researcher Saba Atefyekta who recently completed a PhD in Materials Science at Chalmers. Anand is now CEO of Amferia and will drive the application of the new material and development of the company.

Amferia has previously been noted for an antibacterial wound patch developed by the same team. Amferia now has the innovation of both the new nano-rubber and the antibacterial wound patch. The development of the company and the innovations’ path to making profit are now being carried out in collaboration with Chalmers Ventures, a subsidiary of Chalmers University of Technology.

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

Tough Ordered Mesoporous Elastomeric Biomaterials Formed at Ambient Conditions by Anand K. Rajasekharan, Christoffer Gyllensten, Edvin Blomstrand, Marianne Liebi, Martin Andersson. ACS Nano 2020, 14, 1, 241-254 DOI: https://doi.org/10.1021/acsnano.9b01924 Publication Date:December 17, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Get better protection from a sunscreen with a ‘flamenco dancing’ molecule?

Caption: illustrative image for the University of Warwick research on ‘Flamenco dancing’ molecule could lead to better-protecting sunscreen created by Dr. Michael Horbury. Credit:: created by Dr Michael Horbury

There are high hopes (more about why later) for a plant-based ‘flamenco dancing molecule’ and its inclusion in sunscreens as described in an October 18, 2019 University of Warwick press release (also on EurekAlert),

A molecule that protects plants from overexposure to harmful sunlight thanks to its flamenco-style twist could form the basis for a new longer-lasting sunscreen, chemists at the University of Warwick have found, in collaboration with colleagues in France and Spain. Research on the green molecule by the scientists has revealed that it absorbs ultraviolet light and then disperses it in a ‘flamenco-style’ dance, making it ideal for use as a UV filter in sunscreens.

The team of scientists report today, Friday 18th October 2019, in the journal Nature Communications that, as well as being plant-inspired, this molecule is also among a small number of suitable substances that are effective in absorbing light in the Ultraviolet A (UVA) region of wavelengths. It opens up the possibility of developing a naturally-derived and eco-friendly sunscreen that protects against the full range of harmful wavelengths of light from the sun.

The UV filters in a sunscreen are the ingredients that predominantly provide the protection from the sun’s rays. In addition to UV filters, sunscreens will typically also include:

Emollients, used for moisturising and lubricating the skin
Thickening agents
Emulsifiers to bind all the ingredients
Water
Other components that improve aesthetics, water resistance, etc.

The researchers tested a molecule called diethyl sinapate, a close mimic to a molecule that is commonly found in the leaves of plants, which is responsible for protecting them from overexposure to UV light while they absorb visible light for photosynthesis.

They first exposed the molecule to a number of different solvents to determine whether that had any impact on its (principally) light absorbing behaviour. They then deposited a sample of the molecule on an industry standard human skin mimic (VITRO-CORNEUM®) where it was irradiated with different wavelengths of UV light. They used the state-of-the-art laser facilities within the Warwick Centre for Ultrafast Spectroscopy to take images of the molecule at extremely high speeds, to observe what happens to the light’s energy when it’s absorbed in the molecule in the very early stages (millionths of millionths of a second). Other techniques were also used to establish longer term (many hours) properties of diethyl sinapate, such as endocrine disruption activity and antioxidant potential.

Professor Vasilios Stavros from the University of Warwick, Department of Chemistry, who was part of the research team, explains: “A really good sunscreen absorbs light and converts it to harmless heat. A bad sunscreen is one that absorbs light and then, for example, breaks down potentially inducing other chemistry that you don’t want. Diethyl sinapate generates lots of heat, and that’s really crucial.”

When irradiated the molecule absorbs light and goes into an excited state but that energy then has to be disposed of somehow. The team of researchers observed that it does a kind of molecular ‘dance’ a mere 10 picoseconds (ten millionths of a millionth of a second) long: a twist in a similar fashion to the filigranas and floreos hand movements of flamenco dancers. That causes it to come back to its original ground state and convert that energy into vibrational energy, or heat.

It is this ‘flamenco dance’ that gives the molecule its long-lasting qualities. When the scientists bombarded the molecule with UVA light they found that it degraded only 3% over two hours, compared to the industry requirement of 30%.

Dr Michael Horbury, who was a Postgraduate Research Fellow at The University Warwick when he undertook this research (and now at the University of Leeds) adds: “We have shown that by studying the molecular dance on such a short time-scale, the information that you gain can have tremendous repercussions on how you design future sunscreens.
Emily Holt, a PhD student in the Department of Chemistry at the University of Warwick who was part of the research team, said: “The next step would be to test it on human skin, then to mix it with other ingredients that you find in a sunscreen to see how those affect its characteristics.”

Professor Florent Allais and Dr Louis Mouterde, URD Agro-Biotechnologies Industrielles at AgroParisTech (Pomacle, France) commented: “What we have developed together is a molecule based upon a UV photoprotective molecule found in the surface of leaves on a plant and refunctionalised it using greener synthetic procedures. Indeed, this molecule has excellent long-term properties while exhibiting low endocrine disruption and valuable antioxidant properties.”

Professor Laurent Blasco, Global Technical Manager (Skin Essentials) at Lubrizol and Honorary Professor at the University of Warwick commented: “In sunscreen formulations at the moment there is a lack of broad-spectrum protection from a single UV filter. Our collaboration has gone some way towards developing a next generation broad-spectrum UV filter inspired by nature. Our collaboration has also highlighted the importance of academia and industry working together towards a common goal.”

Professor Vasilios Stavros added, “Amidst escalating concerns about their impact on human toxicity (e.g. endocrine disruption) and ecotoxicity (e.g. coral bleaching), developing new UV filters is essential. We have demonstrated that a highly attractive avenue is ‘nature-inspired’ UV filters, which provide a front-line defence against skin cancer and premature skin aging.”

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

Towards symmetry driven and nature inspired UV filter design by Michael D. Horbury, Emily L. Holt, Louis M. M. Mouterde, Patrick Balaguer, Juan Cebrián, Laurent Blasco, Florent Allais & Vasilios G. Stavros. Nature Communications volume 10, Article number: 4748 (2019) DOI: https://doi.org/10.1038/s41467-019-12719-z

This paper is open access.

Why the high hopes?

Briefly (the long story stretches over 10 years), the most recommended sunscreens today (2020) are ‘mineral-based’. This is painfully amusing because civil society groups (activists) such as Friends of the Earth (in particular the Australia chapter under Georgia Miller’s leadership) and Canada’s own ETC Group had campaigned against these same sunscreen when they were billed as being based on metal oxide nanoparticles such zinc oxide and/or titanium oxide. The ETC Group under Pat Roy Mooney’s leadership didn’t press the campaign after an initial push. As for Australia and Friend of the Earth, their anti-metallic oxide nanoparticle sunscreen campaign didn’t work out well as I noted in a February 9, 2012 posting and with a follow-up in an October 31, 2012 posting.

The only civil society group to give approval (very reluctantly) was the Environmental Working Group (EWG) as I noted in a July 9, 2009 posting. They had concerns about the fact that these ingredients are metallic but after a thorough of then available research, EWG gave the sunscreens a passing grade and noted, in their report, that they had more concerns about the use of oxybenzone in sunscreens. That latter concern has since been flagged by others (e.g., the state of Hawai’i) as noted in my July 6, 2018 posting.

So, rebranding metallic oxides as minerals has allowed the various civil society groups to support the very same sunscreens many of them were advocating against.

In the meantime, scientists continue work on developing plant-based sunscreens as an improvement to the ‘mineral-based’ sunscreens used now.

Needle-free tattoos, smart and otherwise

Before getting to the research news from the University of Twente (Netherlands), there’s this related event which took place on April 18, 2019 (from the Future Under Our Skin webpage (on the University of Twente website) Note: I have made some formatting changes,

Why this event?

Our skin can give information about our health, mood and surroundings. Medical and recreational tattoos have decorated humans for centuries. But we can inject other materials besides ink, such as sensing devices, nano- or bio-responsive materials. With the increased percentage of tattooed population in recent years new health challenges have emerged; but is also a unique possibility to “read from our own skin”, beyond an artistic design. 
 
We have invited scientists, innovators, entrepreneurs, dermatologists, cosmetic permanent make-up technicians, tattoo artists, philosophers, and other experts. They will share with us their vision of the current and future role our skin has for improving the quality of life.

Open Event

This event is open to students, citizens in general as well as societal and governmental organisations around the different uses of our skin. The presence of scientists, medical doctors, tattoo artists and industry representatives is guaranteed. Then, we will all explore together the potential for co-creation with healthy citizens, patients, entreprises and other stakeholders.


If you want to hear from experts and share your own ideas, feel free to come to this Open Event!
 
It is possible to take the dish of the day (‘goed gevulde noedels met kippendij en satésaus en kroepoek’) in restaurant The Gallery (same building as DesignLab) at own costs (€7,85). Of course it is also possible to eat à la carte in Grand Café 

Wanneer: : 18 april 2019
Tijd: :17:30 – 20:00
Organisator: University of Twente
Locatie: Design Lab University of Twente
Hengelosestraat 500
7521 AN Enschede

Just days before, the University of Twente announced this research in an April 16, 2019 news item on Naowerk (Note: A link has been removed),

A tattoo that is warning you for too many hours of sunlight exposure, or is alerting you for taking your medication? Next to their cosmetic role, tattoos could get new functionality using intelligent ink. That would require more precise and less invasive injection technique.

Researchers of the University of Twente now develop a micro-jet injection technology that doesn’t use needles at all. Instead, an ultrafast liquid jet with the thickness of a human hair penetrates the skin. It isn’t painful and there is less waste.

In their new publication in the American Journal of Physics (“High speed imaging of solid needle and liquid micro-jet injections”), the scientists compare both the needle and the fluid jet approach.

Here’s an image provided by the researchers which illustrates the technique they have developed,

Working principle of needle-free injection: laser heating the fluid.The growing bubble pushes out the fluid (medicine or ink) at very high speed. Courtesy: University of Twente

An April 15, 2019 University of Twente press release, which originated the news item, provides more detail about tattoos and the research leading to ‘need-free’ tattoos,

Ötzi the Iceman already had, over 5000 years ago, dozens of simple tattoos on his body, apparently for pain relief. Since the classic ‘anchor’ tattoo that sailors had on their arms, tattoos have become more and more common. About 44 million Europeans wear one or more of them. Despite its wider acceptance in society, the underlying technique didn’t change and still has health risks. One or more moving needles put ink underneath the skin surface. This is painful and can damage the skin. Apart from that, needles have to be disposed of in a responsible way, and quite some ink is wasted. The alternative that David Fernández Rivas and his colleagues are developing, doesn’t use any needles. In their new paper, they compare this new approach with classic needle technology, on an artificial skin material and using high speed images. Remarkably, according to Fernández Rivas, the classic needle technology has never been subject of research in such a thorough way, using high speed images.

Fast fluid jet

The new technique employs a laser for rapidly heating a fluid that is inside a microchannel on a glass chip. Heated above the boiling point, a vapour bubble forms and grows, pushing the liquid out at speeds up to 100 meter per second (360 km/h). The jet, about the diameter of a human hair, is capable of going through human skin. “You don’t feel much of it, no more than a mosquito bite”, say Fernandez Rivas.

The researchers did their experiments with a number of commercially available inks. Compared to a tattoo machine, the micro-jet consumes a small amount of energy. What’s more important, it minimizes skin damage and the injection efficiency is much higher, there is no loss of fluids. And there is no risk of contaminated needles. The current microjet is a single one, while tattooing is often done using multiple needles with different types or colours of ink. Also, the volume that can be ‘delivered’ by the microjet has to be increased. These are next steps in developing the needle-free technology.

Skin treatment

In today’s medical world, tattoo-resembling techniques are used for treatment of skin, masking scars, or treating hair diseases. These are other areas in which the new technique can be used, as well as in vaccination. A challenging idea is using tattoos for cosmetic purposes and as health sensors at the same time. What if ink is light-sensitive or responds to certain substances that are present in the skin or in sweat?

On this new approach, scientists, students, entrepreneurs and tattoo artists join a special event ‘The future under our skin’, organized by David Fernandez Rivas.

Research has been done in the Mesoscale Chemical Systems group, part of UT’s MESA+ Institute.

Here’s a link to an d a citation for the paper,

High speed imaging of solid needle and liquid micro-jet injections by Loreto Oyarte Gálveza, Maria Brió Pérez, and David Fernández Rivas. Journal of Applied Physics 125, 144504 (2019); Volume 125, Issue 14 DOI: 10.1063/1.5074176 https://doi.org/10.1063/1.5074176 Free Published Online: 09 April 2019

This paper appears to be open access.