Dissolvable, microscopic needles light the way for cancer treatments

Light travels at roughly 186,000 miles per second. Yet the moment it encounters human skin, it stumbles, scatters and fades, a natural defense that protects the human body from harmful radiation. But that can also shield diseased tissue from modern light-based therapies designed to treat medical conditions like skin cancer.

For decades, light-based treatments have hit this hard physical wall: light cannot easily penetrate beneath the skin, while conventional drug delivery cannot always precisely reach diseased tissue — or deliver a drug where it can be activated by light.

Now, biomedical researchers at the Texas A&M University College of Engineering and the University of São Paulo have engineered a microscopic breakthrough with the potential to solve both problems at once.

The breakthrough? Hundreds of dissolvable, biocompatible needles, each only a few times wider than a human hair, that can deliver therapeutic drugs and redistribute light beneath the skin.

The team’s dissolving microneedles offer a practically painless, scar-free alternative to surgery and a new path to treating skin cancer and other light-responsive conditions.

The study, published in the Journal of Biomedical Optics and supported by the Cancer Prevention and Research Institute of Texas, Governor’s University Research Initiative, Chancellor’s Research Initiative and the Air Force Office of Scientific Research, was led by Dr. Michelle Requena, a postdoctoral researcher of biomedical engineering, and Dr. Vanderlei Bagnato, distinguished professor of biomedical engineering.

“Skin cancer is a leading health concern in the U.S. and globally,” Bagnato said. “Our approach introduces a local, selective technology designed to reach deeper into skin lesions, deliver therapeutic drugs and guide light to combat skin cancer and diseased tissue.”

The roots beneath the surface

What makes this technology significant is not just the size of the needles, but the scale of the problem they are designed to address.

“Skin cancer is the most frequently diagnosed and most common form of cancer in the United States, and one of the most common across the world,” Bagnato said.

In the U.S. alone, estimates suggest that about 1 in 5 Americans will develop skin cancer in their lifetime. Worldwide, reports show that almost 60,000 people died in 2024 from melanoma.

“It signals the need for policies and interventions that can minimize the severity of skin cancer and improve health and patient outcomes,” Requena said

The high stakes surrounding skin cancer drove the research group to develop an innovative solution: microneedles, though they also hint at broad applicability beyond cancer.

“Across different skin conditions, the microneedles could operate on the same fundamental principle: deliver a pharmaceutical drug deeper into the skin while guiding the light that activates the delivered drug, to treat affected areas,” Requena said.

That principle could shift how clinicians and patients approach light-based therapies — not as general treatments but as precise, localized interventions.

Put simply, instead of flooding the body with a drug or surgically excising a broad area of tissue, the microneedles could equip clinicians with a tool designed to deliver a specific drug, along with the light needed to activate it, directly into diseased tissue and yet preserve the healthy tissue surrounding it.

“Imagine going to the doctor for a skin-related treatment,” Bagnato said. “Tiny, minimally painful needles are briefly inserted into a lesion. They will dissolve, and medicine will penetrate, then light is shined through them. That’s our goal, a compact tool designed to support clinicians and the well-being of patients.”

A needle with two jobs

The heart of this innovation is hidden in plain sight: hundreds of microscopic pyramids, packed together into a dissolvable needle patch.

 Though tiny, their job is anything but small.

“Sometimes patients have multiple lesions and would have to undergo multiple surgical operations. In our approach, the microneedles associated with the light therapy are a biocompatible alternative to surgery and are minimally invasive. Also, the cosmetic effects after treatment are much better than traditional surgery,” Requena said.

In other words, the microneedles are designed to break down and dissolve, offering a scar-free alternative to invasive surgery.

Before dissolving, the pyramid-shaped needles turn the skin from a barrier into a pathway for both medicine and light.

“Their geometry optimizes light distribution and drug delivery beneath the skin, uniformly targeting a tumorous area,” Bagnato said.

Microscopic in size and multifunctional by design, the microneedles open potentially transformative applications for light-based medicine, particularly photodynamic therapy.

Turning light into a treatment

Photodynamic therapy, or PDT for short, turns light into a tool for targeting diseased cells.

“PDT combines a photosensitive drug and a light source, to produce reactive oxygen, which then locally and selectively destroys diseased cells,” Bagnato said.

It relies on three key ingredients: a light-sensitive drug, light and oxygen. The light acts like an on switch for a therapeutic drug, and under the right conditions, can be used to treat conditions such as skin cancer, acne and other skin disorders.

But getting those three ingredients to the same place is easier said than done.

“Light loses intensity as it travels through tissue, which causes the photosensitizing drug to either not fully activate or distribute evenly throughout a lesion,” Requena said.

Previous work by the research group had already shown that the dissolving microneedles produced significantly deeper and more uniform drug distribution throughout an entire tumor section, compared to traditional topical creams.

So, the researchers turned their attention to the next ingredient of PDT, light.

“Could the microneedles also improve light penetration and distribution?” Bagnato said.

Threading the needle, with light

To find out, Requena and Bagnato turned the needles into a light experiment.

They shined a green laser toward an array of microneedles and placed a camera behind the array to capture how the laser emerged. By capturing images from several angles and positions, the researchers could see how the microneedles changed the way light traveled through the array.

“We found that the microneedles helped introduce the light, and distribute it, too,” Bagnato said. “That’s important for real-world practice, as we want to make sure the light is distributed uniformly and that we wouldn’t miss a spot in, for example, a tumor.”

This finding provides compelling evidence that the microneedles could carry out two functions simultaneously within the same treatment: delivering a therapeutic drug and redistributing the light needed to activate it.

While further research and testing is still needed, the team is already preparing to advance their innovation toward clinical trials.

“We expect to conduct our first clinical trial next year, and it will test for non-melanoma skin cancer,” Requena said.

As the team prepares for the next phase of research, the microneedles stand as more than a proof-of-concept. It points toward a new class of integrated biomedical technologies, whereby the delivery system itself becomes part of the treatment.

Where discovery meets impact

The innovation may be microscopic but the research behind it spans continents, disciplines and decades of expertise.

“Our partnerships are very important,” Bagnato said. “It takes bold collaborations and a common vision to learn together and make the right decisions.”

For Requena and Bagnato, translating elegant theories into practical solutions isn’t an exercise in academic curiosity; it’s an ethos of purpose-driven research, aimed at humanity’s betterment.

“Medical and health conditions, like skin cancer, aren’t confined to a single ZIP code,” Bagnato said. “They can affect people across the world. So, our goal is to develop solutions that can advance health, for all of humanity.”

That mission-driven spirit reflects Texas A&M’s broader research enterprise: diverse, multidisciplinary and forward-looking, where discoveries are transitioned into world-class, world-relevant technologies.

“Texas A&M is like a home,” Requena said. “Our ideas are supported, and we have the structure to evolve our projects into impactful applications.”

Ultimately, light may travel at 186,000 miles per second, but its journey to healing isn’t about speed; it’s about direction. These tiny needles could help light find its way to where it is needed the most, and perhaps one day, toward the cure of skin conditions like cancer. 

More Information

Composing drug delivery with light distribution improvement: the use of dissolving microneedles in skin cancer with photodynamic therapy

DOI: https://doi.org/10.1117/1.JBO.31.5.058001, May 9, 2026

By Zaid Elayyan, Texas A&M University Division of Marketing and Communications