Microneedle Skin Patch Measures Cancer Biomarkers

Researchers at the Harvard Wyss Institute have developed a technique that lets clinicians to characterize and monitor melanoma. The system involves using a microneedle patch that can draw deep interstitial fluid into itself through a series of penetrating hyaluronic acid needles. The needles can later be dissolved to release the biomarkers into a test tube before analysis, using a highly sensitive technique called Simoa, to detect individual biomarker protein molecules. The Simoa method involves capturing these molecules using an antibody attached to a magnetic bead, which allows the researchers to use magnets to separate and isolate the molecules for ultimate detection. The approach could permit clinicians to easily identify which melanoma patients are more likely to respond favorably to treatments such as immunotherapies, and also monitor how treatment is progressing.     

Melanoma is a highly aggressive cancer, but has one clinical advantage of being easily accessible on the skin. This means that largely skin-specific technologies, such as microneedle patches, could be useful here. This latest research leverages this to create a microneedle patch that can assist in measuring levels of important biomarkers within melanoma lesions.

While some melanoma patients respond well to certain immunotherapies, approximately 50% do not, and even amongst those that do, treatment resistance can later emerge. Assessing which patients are likely to respond, and determining if treatment is going as planned, may require the analysis of tumor biomarkers. However, it can be difficult to extract such biomarkers from deeper layers of the skin and repeated invasive biopsies to monitor treatment progress is not desirable.

Hence, this latest microneedle patch, which can sample interstitial fluid from within a superficial tumor minimally invasively. “Rapid readout of the responses to melanoma therapy using microneedles may enable effective drug screening and patient stratification to maximize therapeutic benefits,” said Natalie Artzi, a researcher involved in the study.

So far, the researchers have tested the patch in a mouse model of melanoma, and treated the tumors using focused ultrasound and a nanoparticle-based immunotherapy. They were able to detect the rise and fall of biomarkers involved in inflammation that correlated with mouse survival.

“Merely a few microliters of interstitial fluid obtained with microneedles provide a wealth of biomarker information as normal skin cells, local immune cells, and cancer cells constantly secrete diverse signaling molecules and metabolites,” said Daniel Dahis, another researcher involved in the study. “After the microneedles are retrieved, their tips can be simply dissolved to release the captured molecules into a test tube for us to start the biomarker analysis.”

Study in journal Advanced Functional Materials: Monitoring Melanoma Responses to STING Agonism and Focused Ultrasound Thermal Ablation Using Microneedles and Ultrasensitive Single Molecule Arrays

Via: Wyss Institute