Development of a mertansine-specific DNA aptamer and novel high-throughput sandwich enzyme-linked oligonucleotide assay for quantification and characterization of trastuzumab emtansine.

We developed a novel DNA aptamer, D8#24S1, which specifically recognizes mertansine (DM1), the cytotoxic payload of the antibody-drug conjugate (ADC) trastuzumab emtansine (T-DM1), and applied it for T-DM1 analysis. D8#24S1 was obtained through SELEX and was shown to specifically recognize DM1 with high affinity (dissociation constant, K = 84.2 nM).

Simple and fast one-step FRET assay of therapeutic mAb bevacizumab using anti-idiotype DNA aptamer for process analytical technology.

We developed an aptamer-based fluorescence resonance energy transfer (FRET) assay capable of recognizing therapeutic monoclonal antibody bevacizumab and rapidly quantifying its concentration with just one mixing step. In this assay, two fluorescent dyes (fluorescein and tetramethylrhodamine) labeled aptamers bind to two Fab regions on bevacizumab, and FRET fluorescence is observed when both dyes come into close proximity. We optimized this assay in three different formats, catering to a wide range of analytical needs.

Development of an on-site therapeutic drug monitoring method using a portable spectrometer.

We report on the development of an on-site therapeutic drug monitoring (TDM) method for vancomycin (VCM) utilizing a portable spectrometer and commercially available immunoturbidimetric assay reagents designed for automated clinical chemistry analyzers. The method enables the quantification of VCM in plasma samples within 10 min, with a good correlation between the measured values and the theoretical values (r = 0.995).

Precolumn derivatization LC/MS method for observation of efficient hydrogen sulfide supply to the kidney via d-cysteine degradation pathway.

d-Cysteine (d-Cys) is metabolized to hydrogen sulfide (HS) by d-amino acid oxidase (DAO)/3-mercaptopyruvate sulfurtransferase pathway. The pathway is required for HS supplementation that ameliorates acute kidney injury after the oral administration of d-Cys in mice. However, whether the rate-limiting activity of DAO regulates the tissue-selectivity or the extent of d-Cys degradation and HS supplementation remains unclear.