Heart-cut 2DSEC-RP-LC-ICP-MS as a screening tool in metal-based anticancer research

Abstract

In this work, we introduce a new screening tool for metal-based anticancer drugs, enabled by on-line heart-cut two-dimensional liquid chromatography combined with inductively coupled plasma mass spectrometry (2DLC-ICP-MS). This method employs ultrahigh performance size-exclusion chromatography (UHPLC SEC) in the first dimension and reversed phase liquid chromatography (RP-LC) in the second dimension. In this way, the quantification of free and intact metal-based anticancer drugs was addressed in biologically relevant matrices without otherwise necessary sample preparation steps such as protein removal and extraction of the drug. In a proof of principle study the half-life of oxaliplatin upon ex vivo incubation in serum and cellular extracts was assessed by repeated analysis every 25 min over several hours. This method showed good column recoveries for intact oxaliplatin (80% assessed by on-line isotope dilution) and limits of detection <3 nM. Oxaliplatin exhibited a half-life of 1.6 ± 0.1 h (N = 3) in serum. In the cellular extract prepared from the colorectal cancer cell line HCT116 oxaliplatin showed a prolonged half-life of 3.5 ± 0.3 h and 4.2 ± 0.4 h, assuming zero order or first order kinetics, respectively.