Inflammatory bowel disease (IBD), affecting approximately 1.6 million people in the United States, necessitates continuous monitoring due to its unpredictable pattern of remission and relapse. Conventional imaging techniques like colonoscopy and endoscopy are invasive and costly, prompting exploration of noninvasive biomarker-based methods using fecal and blood samples. However, traditional biomarkers such as calprotectin and MPO lack specificity and are influenced by various factors, limiting their accuracy in assessing inflammation severity and location.
To overcome these limitations, a smart ingestible capsule is proposed. This capsule integrates a paper-based myeloperoxidase (MPO) sensor, a miniaturized photodetector, and embedded electronics for wireless data transmission. The capsule features a pH-responsive coating to delay MPO measurements until reaching the proximal small intestine or large intestine, where inflammation is typically present. Upon contact with GI fluid, the MPO sensor triggers a chemiluminescent reaction, emitting blue light proportional to MPO concentration.
The sensor demonstrates linear sensitivity within the physiological MPO concentration range, effectively identifying inflammation risk in GI fluid. The emitted luminescence is converted into an electrical signal by the photodetector, producing a quantifiable energy output with a sensitivity of 6.14 µJ/U.ml-1. Tested with GI fluids from pig models simulating various inflammation states, the capsule consistently activated in the intended region and accurately detected MPO levels with less than a 5% variation between readings in GI fluid and a PBS solution.
This innovative capsule presents a promising solution for personalized IBD management by enabling frequent and targeted inflammation analysis within the GI tract. With its capability to assess medication efficacy and detect early relapse, this technology represents a significant advancement in IBD care, potentially transforming therapeutic strategies and enhancing patient outcomes.