Light therapy has been gaining attention in skincare and dermatology for its ability to address various skin issues, from healing wounds to improving texture. But recent research is shedding new light on how we can make this treatment even more precise and effective. A 2025 study published in Advanced Healthcare Materials by Longobardi and colleagues introduces an exciting development: light-activatable hyaluronic acid derivatives that release nitric oxide, offering a fresh way to harness light therapy for skin health.
To understand this breakthrough, let’s start with the key players involved. First, hyaluronic acid (HA) is a substance naturally found in our skin. It’s like a moisture magnet, helping keep skin plump, hydrated, and flexible. Because our bodies already recognize HA, it’s a safe and well-tolerated material, often used in skincare products and medical treatments.
The second key player is nitric oxide (NO). You might not hear much about it, but this small molecule is crucial for skin health. It helps widen blood vessels, boosting blood flow to the skin—important for delivering nutrients and removing waste. It also has anti-inflammatory properties, which can calm irritated skin, and it supports the healing process, making it useful for everything from minor cuts to more complex skin issues.
The problem? Getting NO to where it’s needed in the skin, and releasing it at the right time, has been tricky. If released too early or in the wrong place, it might not work as well, or could even cause unwanted effects. That’s where light therapy comes in.
Longobardi and the research team came up with a smart solution: they modified hyaluronic acid to create a “carrier” that holds onto nitric oxide until it’s triggered by light. Think of it as a tiny, light-sensitive package. The HA derivative is designed to stay stable—keeping the NO locked inside—until exposed to a specific type of light. When the light hits the skin, it activates the HA derivative, causing it to release the NO exactly where it’s needed.
This approach has two big advantages. First, it’s targeted. By using light to trigger release, doctors or users can control where and when the NO is released. For example, if someone has a specific area of inflamed skin or a wound, they can apply the HA derivative and then use light only on that spot, ensuring the NO works right there. This reduces the risk of NO affecting other areas unnecessarily.
Second, using HA as the carrier is a smart choice. Since HA is naturally present in the skin, the body doesn’t see it as a foreign substance. This means the derivative is less likely to cause irritation or allergic reactions, making it safe for most people. Plus, HA can penetrate the skin’s layers effectively, carrying the NO with it to reach deeper areas where it can do the most good—something many topical treatments struggle with.
So, how does this combination of light, HA, and NO actually benefit the skin? The study focuses on several key effects.
First, improved blood flow. When NO is released, it relaxes the blood vessels in the skin, letting more blood flow through. This brings more oxygen and nutrients to skin cells, which helps them function better and repair themselves. For example, in aging skin, where blood flow can slow down, this boost might help restore a healthier, more vibrant look.
Second, reduced inflammation. Inflammation is the skin’s natural response to irritation, but when it’s chronic, it can lead to redness, swelling, or conditions like eczema. NO’s anti-inflammatory properties help calm this response, soothing the skin and reducing discomfort.
Third, enhanced healing. Whether it’s a small scrape or a more serious wound, the skin needs to repair itself by growing new cells and forming new tissue. NO supports this process by encouraging cell growth and helping form the structures needed for healing. By delivering NO directly to the wound site via the light-activated HA, the therapy could speed up recovery time.
The researchers also tested how well this system works in delivering NO to the skin. They found that the HA derivative effectively penetrates the outer layers of the skin, reaching the deeper dermis where many important skin processes happen. Once there, exposure to light triggers a steady release of NO—enough to have a meaningful effect, but not so much that it causes issues. This balance is key: too little NO won’t work, but too much could be harmful.
What’s most exciting is how this combines the benefits of light therapy with the natural properties of HA and NO. Traditional light therapy uses different wavelengths of light to treat skin issues, but it often relies on the skin’s own responses to light. This new approach adds a layer of control, using light to “switch on” a powerful, natural healing molecule exactly where it’s needed.
Looking ahead, this research could open doors for better treatments. Imagine a skincare product or medical cream that you apply to a problem area, then activate with a small light device at home or in a doctor’s office. It could be used for everything from treating acne (by reducing inflammation) to speeding up wound healing after surgery, or even improving the appearance of aging skin by boosting circulation.
Of course, more research is needed to fine-tune the system—like figuring out the best type of light, how long to apply it, and how to make the treatment work for different skin types. But the study by Longobardi and colleagues is a promising step forward, showing that by combining natural substances with light therapy, we can create more effective, targeted treatments for the skin.
In conclusion, this new discovery highlights how light therapy can be made more precise and powerful when paired with modified hyaluronic acid that releases nitric oxide. By controlling where and when nitric oxide is delivered, this approach offers exciting possibilities for improving skin health, from reducing inflammation to speeding up healing. As research continues, we may soon see this innovative method become a key part of skincare and dermatological treatments.
Reference:
Longobardi G, Parisi C, Sodano F, Catanzano O, Porzio AD, Randazzo A, Sortino S, Quaglia F. Light-Activatable Hyaluronic Acid-Derivatives Releasing Nitric Oxide and Their Delivery in the Skin. Adv Healthc Mater. 2025 Jun;14(15):e2500589. doi: 10.1002/adhm.202500589. Epub 2025 Apr 18. PMID: 40249115; PMCID: PMC12147995.
