Sequential enzymatic derivatization coupled with online microdialysis sampling for simultaneous profiling of mouse tumor extracellular hydrogen peroxide, lactate, and glucose.

Probing tumor extracellular metabolites is a vitally important issue in current cancer biology. In this study an analytical system was constructed for the in vivo monitoring of mouse tumor extracellular hydrogen peroxide (HO), lactate, and glucose by means of microdialysis (MD) sampling and fluorescence determination in conjunction with a smart sequential enzymatic derivatization scheme-involving a loading sequence of fluorogenic reagent/horseradish peroxidase, microdialysate, lactate oxidase, pyruvate, and glucose oxidase-for step-by-step determination of sampled HO, lactate, and glucose in mouse tumor microdialysate. After optimization of the overall experimental parameters, the system's detection limit reached as low as 0.

Online open-tubular fractionation scheme coupled with push-pull perfusion sampling for profiling extravasation of gold nanoparticles in a mouse tumor model.

The extravasation of administered nano-drug carriers is a critical process for determining their distributions in target and non-target organs, as well as their pharmaceutical efficacies and side effects. To evaluate the extravasation behavior of gold nanoparticles (AuNPs), currently the most popular drug delivery system, in a mouse tumor model, in this study we employed push-pull perfusion (PPP) as a means of continuously sampling tumor extracellular AuNPs. To facilitate quantification of the extravasated AuNPs through inductively coupled plasma mass spectrometry, we also developed a novel online open-tubular fractionation scheme to allow interference-free determination of the sampled extracellular AuNPs from the coexisting biological matrix.