Engineering ingestible nanosensors for breath-based detection of colorectal cancer - Project Summary/Abstract Colorectal cancer is the second leading cause of cancer death in the United States, and early detection is key to reducing the 53,000 deaths per year. Current screening relies on tests for fecal biomarkers, which have good sensitivity for advanced-stage CRC but poor sensitivity for early- stage CRC. For this reason, direct visualization of the colon via colonoscopy remains the gold standard for early detection. However, the invasiveness of colonoscopy deters individuals from completing regular recommended testing, and nearly 25% of cases are diagnosed when the cancer has spread to distant sites resulting in a greater than 70% drop in 5-year survival rate. Thus, there remains an outstanding need for non-invasive and sensitive diagnostic tests to improve adherence to screening guidelines and, ultimately, improve the rate of early detection. This proposal aims to develop ingestible nanosensors that are engineered to sense disease activity in the intestine and produce amplified reporter signals in breath (i.e. synthetic breath biomarkers) for early-stage CRC detection. More specifically, nanosensors will be designed to sense the activity of particular enzymes in the intestinal mucosa that play significant roles in tumor development. These include host enzymes that regulate growth and angiogenic factors and remodel the extracellular matrix for tumor invasion as well as enzymes from the microbiome that promote tumorigenesis through activation of genotoxic compounds. To harness intestinal enzyme activities for breath-based CRC detection, a panel of nanosensors engineered to sense orthogonal enzyme targets will be barcoded with volatile reporters of distinct mass for multiplexed analysis. Nanosensors will be formulated for oral delivery, and after reaching the intestine, will release reporters upon degradation by their enzyme targets. Liberated reporters will be exhaled in a matter of minutes due to rapid volatile clearance mechanisms. Altogether, this will culminate in a breath biomarker signature for CRC that is detectable by mass spectrometry. Ingestible nanosensors will be tested in animal models of CRC, where enzyme-amplified breath signals may drive sensitive tumor detection, and multiplexed breath signals are expected to facilitate highly specific disease detection. Success of this platform technology would provide a path to noninvasive, breath-based detection for a broad range of GI diseases and, thus, eliminate the logistical barriers to early disease detection.
