Microfluidic chip interfacing microdialysis and mass spectrometry for in vivo monitoring of nanomedicine pharmacokinetics in real time

Although liposomes have demonstrated significant clinical success as drug delivery vehicles, pharmacokinetic (PK) profiling of liposomal nanomedicines remains difficult due to technical challenges accurately measuring low concentrations of free drug in complex biological matrices. Microdialysis (MD) is well established as a powerful in vivo sampling tool for PK studies, but non-volatile salts present in the microdialysate are incompatible with mass spectrometry (MS) analysis without tedious sample pre-treatment. To address this issue, a µSPE-based microfluidic chip was fabricated to interface MD with MS. By incorporating PEG 20,000 as an effective anti-foulant, the µSPE-based microfluidic chip demonstrated excellent efficiencies in drug extraction and de-salting of the microdialysate, providing a promising approach to real-time monitoring of nanomedicine PK profiles.