Qi-Xuan Sun,Xing Wei,Shang-Qing Zhang,Ming-Li Chen,Ting Yang,Jian-Hua Wang
It is of great importance to elucidate the fate of drugs, e.g., their cellular uptake, transport and metabolism/excretion at single cell level. In the present work, cellular uptake and excretion of curcumin in HepG2 and MCF-7 cells were investigated by measuring 59 Co in a curcumin cobalt complex ([Co(tpa)(cur)](ClO 4 ) 2 ) with inductively coupled plasma mass spectrometry (ICPMS). The uptake and distribution pattern of the metal drug complex in single cells were thoroughly studied, demonstrating extremely large discrepancy of uptake behavior among individual cells. The complex concentration-dependent uptake and excretion behavior is observed for both HepG2 and MCF-7 cells. The uptake of ([Co(tpa)(cur)](ClO 4 ) 2 ) by HepG2 cells is firstly increased with the concentration of the complex followed by level-off at certain level. On the other hand, however, the uptake by MCF-7 cells increases exponentially with the complex concentration within a same concentration range. The present study provides important information on the transport process of the metal drug complex at single cell level, it may be promising for further applications in the elucidation of metal drug effectiveness in vivo.
Xun Liu,Shang-Qing Zhang,Zi-Han Cheng,Xing Wei,Ting Yang,Yong-Liang Yu,Ming-Li Chen,Jian-Hua Wang
A highly sensitive platform is developed for the determination of microRNA-21 (miRNA-21) with inductively coupled plasma mass spectrometry (ICPMS). It includes the following operations: Hairpin structures DNA H1 and H2 are designed, and DNA H1 is bound to ultrasmall lanthanide upconversion nanoparticles (UCNPs) to produce UCNPs@DNA conjugate probes. Target miRNA triggers a chain reaction for alternating hybridization between DNA H1 (bound on UCNPs@DNA probe) and DNA H2. This leads to UCNPs accumulation and serves as an efficient amplification strategy for UCNPs. The concentration of miRNA-21 is closely correlated to the number of UCNPs; thus, the detection of 89Y by ICPMS provides a promising approach for miRNA quantification. This protocol exhibits high sensitivity to miRNA-21 within 0.1–500 fM, along with a detection limit of 41 aM, which is among the hitherto reported most sensitive procedures. It is worth mentioning that rare earth elements are scarcely present in living systems, which minimizes the background for ICPMS detection and excludes potential interferences from the coexisting species, which is most suited for biological assay.