A microneedle patch for breast cancer screening via minimally invasive interstitial fluid sampling

Early diagnosis and treatment are crucial for breast cancer patients. Interstitial fluid (ISF) shows promise for early disease screening, but its extraction for biomarker detection is challenging. To address this, we designed a microneedle (MN) patch for minimally invasive and rapid ISF extraction through materials engineering, which could improve cancer detection, ease the burden on medical resources, and increase patient compliance. Via UV crosslinking, the water absorbing moiety, acrylic acid (AA), can be polymerized and crosslinked with gelatin methacrylate (GelMA). The resulting GelMA-AA MN (G-A MN) can rapidly extract different analytes. One piece of G-A MN patch can aspirate about 1.29 mg (≈ 1.29 µL) of ISF from mice within 60 s. We further applied G-A MN for breast cancer screening in the 4T1 orthotopic mice breast cancer model and genetically engineered breast cancer model. By measuring the tumor markers carcinoembryonic antigen (CEA) and glycoantigen CA15-3, G-A MN could detect the cancer occurrence earlier than other standard screening methods, including blood tests, ultrasound, or Micro-CT. Furthermore, earlier diagnosis led to timely chemotherapy treatment and resulted in prolonged survival in the mice 4T1 breast cancer model. In conclusion, G-A MN enabled rapid ISF extraction for biomarker analysis in a minimally invasive manner. G-A MN facilitated detection outperformed other common diagnostic methods, representing a promising alternative breast cancer screening strategy.