Fluorescent immunochromatographic test strip for therapeutic drug monitoring of methotrexate with high sensitivity and wide dynamic range.

Abstract

As a front-line chemotherapeutic drug for maintenance and consolidation therapy, methotrexate (MTX) has widely been applied to treat various tumors and some inflammatory diseases. However, because of its severe toxicity ascribed to low selectivity, it is necessary to monitor therapeutic drugs in high-dose MTX therapeutic regimens to ensure treatment safety. In this work, we developed a fluorescent immunochromatographic test strip (FITS) for monitoring MTX by employing time-resolved fluorescent microspheres as signal probes. With a competitive immunoassay mode, the FITS for MTX shows a super-wide dynamic range of 10pM-10μM, covering the entire clinical therapeutic concentration range of MTX. Therapeutic drug monitoring of MTX can be achieved within 7min with high specificity, facilitating the timely rescue of drug poisoning led by high-dose MTX treatment. The methodwasemployedfor monitoring MTX in the spiked human serum, urine, and milk, showing acceptable recoveriesranging from 94.0 to 110.0%. The established FITS has been applied toMTX detection in serum obtained from high-dose MTX treatment. The results from FITS and enzyme multiplied immunoassay technique showed no significant difference, suggesting its reliability for usage in real biological samples. The device shows promise in point-of-caretherapeutic drug monitoring for resource-limited countries and institutes, which significantly facilitates overcoming the lag time between sampling and results.