New light-triggered microneedle patch could make IVF hormone delivery painless and automated: Study

A McGill University research team has developed a painless, automated way to deliver in vitro fertilization (IVF) hormones using a light-activated microneedle patch, an innovation that could ease one of the most stressful parts of fertility treatment and open new possibilities for other diseases that require frequent, time-sensitive injections.

IVF patients must inject themselves with hormones daily at specific times in the weeks leading up to egg retrieval, a process that can be physically and emotionally taxing.

The team’s new system uses a hydrogel microneedle patch filled with specially engineered nanoparticles that hold and release a key IVF hormone, leuprolide, when stimulated by near-infrared light. The light can be programmed to release the drug at the desired time.

Toward personalized, programmable dosing

Current light-triggered drug delivery systems often release foreign materials into the body, posing regulatory and safety challenges.

“This is the first time that we were able to show light-triggered drug release from a nanoparticle-microneedle composite without releasing any foreign substance into the body,” said Marta Cerruti, a materials engineering professor and senior author of the study in Small.

The researchers say this key advance could accelerate clinical translation, as the delivery system leaves no nanoparticles behind in the skin.

In building their system, the team first optimized how many hormone-bearing nanoparticles could be incorporated into each microneedle without weakening its ability to penetrate skin. They then tested whether the light trigger could release the hormone into a porcine skin model over two hours. Finally, they demonstrated that even a short five-minute pulse of light released measurable levels of leuprolide into the skin, bloodstream and organs of a live rat.

“The light can also be programmed to release the drug at the specific time the drug is needed, which could differ for each individual,” said Tam, the PhD student in Cerruti’s lab who was also the lead author on this study.

“IVF success rates are at best 30 per cent, even for the youngest women. The hope is that if you take out the human error with injecting yourself and deliver the drug at times optimized for each patient, you could potentially see this success rate go up,” she said.

Beyond IVF

For IVF patients, the technology could make treatment easier, less painful and potentially more effective, but the system could also help anyone who relies on daily injections, including people with diabetes or multiple sclerosis.

Because no nanoparticles enter the body, the researchers say the platform has a clearer pathway to clinical adoption than previous systems. More work is planned to refine dosing, explore hormone release profiles and investigate commercial possibilities.

Reference:

Vivienne Tam et al, Upconverting Nanoparticle‐Loaded Microneedles for Near‐Infrared Responsive Delivery of Gonadotropins to Increase Success of In Vitro Fertilization, Small (2025). DOI: 10.1002/smll.202513138