Discovery of NMP22-Targeting Aptamers for Point-of-Need Test of Bladder Cancer

Bladder cancer is among the most prevalent urological malignancies worldwide and is associated with high mortality, yet accessible point-of-need testing and large-scale screening strategies remain limited. Nuclear matrix protein 22 (NMP22) is a well-established urinary biomarker for bladder cancer released during tumor development. However, current detection methods suffer from limitations such as inadequate sensitivity, high cost, and lengthy processing times. Herein, we employed SELEX to identify high-affinity aptamers targeting NMP22, aiming to enable broad and convenient screening for bladder cancer. A DNA aptamer, NT2a, with a dissociation constant (K_d) of 24.26 ± 10.47 nM, was identified and employed as the recognition element to develop both lateral-flow immunoassay (LFIA) and enzyme-linked immunosorbent assay (ELISA) platforms. Evaluation in a clinical cohort yielded positive detection rates of 89.47% and 93.75% for LFIA and ELISA, respectively, with both assays demonstrating high specificity, supporting their effectiveness for point-of-need detection of bladder cancer using urine samples. Although NMP22 immunoassays are widely used in clinical practice, aptamer-based technologies are emerging as powerful alternatives, offering enhanced sensitivity and potentially lower cost, particularly for point-of-care, noninvasive surveillance of bladder cancer recurrence.