Painless Microneedle Skin Patch Monitors Immune Health

Many critical immune cells reside in tissues such as the skin, making them difficult to access without surgical procedures. This limitation is especially challenging for older adults, children, and patients with visible skin conditions. Researchers have now developed a bandage-like microneedle patch that painlessly samples immune cells and inflammatory signals directly from the skin.

The patch, developed by researchers at The Jackson Laboratory (JAX, Bar Harbor, ME, USA), in collaboration with the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA), contains hundreds of microscopic needles made from an FDA-approved polymer and coated with a seaweed-derived hydrogel. These microneedles penetrate only the upper layers of the skin without reaching nerves or blood vessels. By briefly reactivating resident memory T cells with a small amount of antigen, the patch triggers a natural immune response that attracts additional immune cells, which are then absorbed into the hydrogel for analysis.

In mouse vaccination models, the patch significantly increased recovery of antigen-specific T cells, many of which were recruited from the bloodstream. In an initial human study conducted at UMass Chan, the patch successfully collected a diverse mix of immune cells and signaling proteins, including resident memory T cells. The study, published in Nature Biomedical Engineering, represents the first demonstration of live human immune cell sampling using a microneedle patch. The device detected inflammatory signals within minutes and captured specialized immune cells within hours.

The microneedle platform may complement traditional blood tests and biopsies by offering a less invasive method for monitoring immune responses to vaccines, infections, autoimmune diseases, and cancer therapies. It could be particularly valuable for skin disorders such as psoriasis and vitiligo, where immune activity is localized in tissue. Future research will explore broader clinical applications and potential adaptations for at-home use or sampling in oral and nasal tissues. Additional studies are underway to evaluate performance across diverse diseases and patient populations.

“This study marks the first demonstration of live human immune cell sampling using a microneedle patch. This opens the door to a new way of monitoring immune responses that’s practical, painless, and clinically feasible,” said Sasan Jalili, lead author of the study. “People wouldn’t need hours of sampling. Even 15 to 30 minutes can be enough to detect inflammatory signals and get a sense of what’s happening in the tissue.”

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