Researchers at Northwestern University have developed a synthetic melanin cream that protects and heals skin from sun and environmental damage by scavenging free radicals. Potential applications include sunscreen, wound healing, and protection against environmental toxins, and clinical trials are nearing. Above is inflamed skin with free radicals (green) visible within the skin. ROS are “reactive oxygen species,” or free radicals.Credit: Yu Chen, Northwestern University
Synthetic creams protect the skin from sun damage.
Imagine a skin cream that repairs the damage caused by daily exposure to sunlight and environmental toxins. Scientists at Northwestern University have developed a biomimetic melanin synthetic material that allows you to do just that.
This synthetic melanin is designed to mimic natural human skin melanin and has been shown to promote wound healing when applied topically to injured skin. These effects occur both on the skin itself and throughout the body.
Scientists say that when applied as a cream, synthetic melanin can protect skin from sunlight and heal skin damaged by sun damage or chemical burns. This technology works by removing free radicals produced by damaged skin such as sunburn. If left unchecked, free radicals can damage cells and eventually lead to skin aging and skin cancer.
This study was recently published in the journal npj regenerative medicine.
Melanin in humans and animals provides pigmentation to the skin, eyes, and hair. This substance increases pigmentation in response to sunlight, protecting cells from sun damage through a process commonly referred to as tanning. The same pigments in the skin also naturally scavenge free radicals in response to harmful environmental pollution from industrial sources and automobile exhaust.
“People don’t think of their daily lives as damaging to their skin,” said co-author Dr. Kurt Lu, Eugene Bauer and Gloria Bauer Professor of Dermatology. northwestern university Dermatologist at Feinberg School of Medicine and Northwestern Medicine. “Walking barefaced in the sun every day exposes you to low-intensity, continuous UV radiation. This is even worse during peak daytime hours and during the summer months. We know that skin that is protected by clothing ages less, whereas skin that is protected by clothing does not age as much.”
B-roll from study author Dr. Kurt Lu’s dermatology lab.Credit: Northwestern University
Skin also ages due to aging over time and external environmental factors such as environmental pollution.
“All these attacks on the skin generate free radicals that cause inflammation and destroy collagen,” Lu said. “That’s one reason why older skin looks so different than younger skin.”
When scientists created melanin-engineered synthetic nanoparticles, they changed the structure of melanin so that it had higher free radical scavenging ability.
Synthetic melanin is applied to inflamed skin. Just below the surface of the skin are green free radicals, also known as ROS or “reactive oxygen species.”Credit: Yu Chen, Northwestern University
“Synthetic melanin is able to scavenge more radicals per gram compared to human melanin,” said co-author, Department of Chemistry, Materials Science and Engineering, and Biomedical Engineering Department at Northwestern University. said Nathan Gianneschi, Jacob and Rosalyn Cohn Professor of Pharmacology. “It’s like supermelanin. It’s biocompatible, degradable, non-toxic, and transparent when applied to the skin. Our research shows that it acts as an effective sponge, drawing out harmful factors. remove it and protect your skin.”
When applied to the skin, melanin remains on the surface and is not absorbed by the underlying layers.
“Synthetic melanin stabilizes the skin and puts it on a healing path. This is seen both superficially and throughout the body,” Gianneschi said.
Turning to a new theory
Scientists who have been studying melanin for nearly a decade first tested synthetic melanin as a sunscreen.
“It protected the skin and skin cells from damage,” Gianneschi said. “We then thought that synthetic melanin, which primarily has the ability to absorb radicals, could be applied topically after a skin injury to have a healing effect on the skin. That’s exactly what it does. I understand that.”
Lu envisions synthetic melanin creams being used as sunscreen boosters for added protection and as moisturizer enhancers to promote skin repair.
Diagram of the layer of synthetic melanin on top of inflamed skin.Credit: Yu Chen, Northwestern University
“You can also wear it before you go out in the sun and after you get out of the sun,” Lu said. “In both cases, we saw a reduction in skin damage and inflammation. It protects and repairs the skin at the same time. It’s an ongoing repair.”
The cream could also be used for blisters and sores, Lu said.
Topical creams calm the immune system
Gianneschi and Lu found that synthetic melanin cream calms the immune system by absorbing free radicals after an injury. The outer layer of mature skin cells, the stratum corneum, communicates with the epidermis below. It is the surface layer and receives signals from the body and the outside world. By calming down that destructive inflammation on the surface, the body can begin to heal rather than become more inflamed.
“The epidermis and upper layers are connected to the rest of the body,” Lu says. “This means that stabilizing these upper layers may lead to an active healing process.”
How the experiment works
Scientists used chemicals to create a blistering reaction on human skin tissue samples in a dish. Blisters appeared when the upper layers of the skin separated from each other.
“It was very inflamed, like a poison ivy reaction,” Lu said.
Skin treated with synthetic melanin is now recovering. Inflamed skin.Credit: Yu Chen, Northwestern University
They waited several hours and then applied topical melanin cream to the damaged skin. Within the first few days, the cream boosted the immune response by first helping restore the skin’s own radical scavenging enzymes and then stopping the production of inflammatory proteins. This started a cascade of reactions that were observed to significantly increase cure rates. This includes preserving the healthy skin layer underneath. Blisters persisted in samples that did not undergo melanin cream treatment.
“This treatment has the effect of putting the skin through a cycle of healing and repair that is regulated by the immune system,” Lu said.
Melanin may protect people from toxins such as nerve agents
Gianneschi and Lu are members of the U.S. Department of Defense (DOD) and National Institutes of Health (NIH (National Institutes of Health). This includes considering melanin as a dye for clothing, which also acts as an absorbent for toxins in the environment, especially nerve agents. They made military uniforms with melanin. They showed that they could be dyed black and that melanin absorbed nerve gas.
Melanin also absorbs heavy metals and toxins. “While it may work this way naturally, we used a synthetic version and designed it to optimize absorption of these toxic molecules,” Gianneschi said.
B-roll from study author Nathan Gianneschi’s chemistry lab.Credit: Northwestern University
Scientists are conducting clinical trials to test the efficacy of synthetic melanin creams. As a first step, scientists recently completed tests showing that synthetic melanin does not irritate human skin.
Researchers speculate that this could be an effective treatment for skin burns caused by radiation exposure, based on observations that melanin protects living tissue from high-energy radiation.
This promising research may provide future treatment options for cancer patients receiving radiation therapy.
Reference: “Topical application of synthetic melanin promotes tissue repair” Dauren Biyashev, Zofia E. Siwicka, Ummiye V. Onay, Michael Demczuk, Dan Xu, Madison K. Ernst, Spencer T. Evans, Cuong V. Nguyen, Florencia A. Sons, Navjit K. Paul, Naneki C. McCallum, Omar K. Farha, Stephen D. Miller, Nathan C. Gianneschi, Kurt Q. Lu, November 2, 2023; npj regenerative medicine.
DOI: 10.1038/s41536-023-00331-1
Other Northwestern authors include Doren Byashev, Zofia Siwicka, Umie Onai, Michael Demchuk, Madison Ernst, Spencer Evans, Cuong Nguyen, Florencia Song, Navjit Paul, Naneki McCollum, and Omar – Includes Farha, Stephen Miller, and Dan Xu.
This research was supported by grant U54 AR079795 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the NIH and grant FA9550-18-1-0142 from the Department of Defense.
