Development of a Method for the Quantification of the Molar Gold Concentration in Tumour Cells Exposed to Gold‐Containing Drugs

Abstract

The knowledge of the cellular molar concentration of a drug is an extremely important parameter for the discussion and interpretation of its efficacy and bioavailability. Concerning metal complexes, electrothermal atomic absorption spectroscopy (ETAAS) offers a valuable analytical tool. However, matrix effects often hamper proper quantification of the metal concentration in biological tissues. This paper describes the development of an ETAAS method for the quantification of the molar gold concentration in HT-29 colon carcinoma cells. ETAAS analytical conditions were optimised and a factor was developed which allows the calculation of the molar cellular gold concentration from the measured gold per cellular biomass value. The method was used to quantify the gold content in HT-29 cells after exposure to the gold drug auranofin. Results indicated a strong cellular uptake of auranofin (compared to other metal anticancer drugs), which significantly correlated with the antiproliferative effects triggered by this agent.

Specific labeling with potent radiolabels alters the uptake of cell‐penetrating peptides

“…This technique makes use of the fact that vaporized metals can be detected with high selectivity and sensitivity in biological matrix and consequently plays an important role in bioanalytical studies on metallodrugs. 15,20,21 In contrast to the above described results compound 6 showed only marginal cellular uptake values (see, Figure 2). The NBD analogue of this peptide (3) had shown the highest uptake efficiency among the NBD-labeled derivatives (see Figure 1).…”

Quantifizierung der Zellaufnahme metallierter Peptide und Peptidnucleinsäuren durch Atomabsorptionsspektroskopie

“…[10] Die molare Zellkonzentration wurde wie in der Literatur beschrieben berechnet. [25] Zur Quantifizierung der Aufnahme in die Zellkerne wurden die Pellets ebenfalls wie beschrieben bearbeitet. [11] Cytotoxizitätsexperimente: Die Effekte der Zellwachstumshemmung wurden wie bereits beschrieben untersucht und ausgewertet.…”

“…[11] Cytotoxizitätsexperimente: Die Effekte der Zellwachstumshemmung wurden wie bereits beschrieben untersucht und ausgewertet. [25] Eingegangen am …”

“…Aus bekannten Zellparametern wie dem mittleren Proteingehalt der Zellen und dem mittleren Zellvolumen kann die intrazelluläre molare Konzentration der Testverbindungen aus dem bestimmten Metallgehalt (pmol Metall pro mg Protein) berechnet werden. [25] Für die Verbindungen mit den höchsten Aufnahmeraten (5 Co und 6 Co nach 24 h) werden intrazelluläre Konzentrationen von > 70 mm gefunden, wohingegen nur ca. 6 mm bei den Verbindungen mit der niedrigsten Zellaufnahme nach 6 h erreicht werden (2 Co nach 6 h).…”

Substitution of Metallocenes with [2.2]Paracyclophane to Enable Confocal Microscopy Imaging in Living Cells

“…Cytotoxicity assay: The antiproliferative effects were determined according to a recently used method with minor modifications. [29] In short: HT-29 cells (100 μL, 2565 cells/mL) or MDA-MB-231 (100 μL, 4120 cells/mL) were transferred into 96-well plates and incubated at 37°C and 5 % CO 2 for 72 h. Stock solutions of the compounds in DMF were freshly prepared and diluted with the respective cell culture medium to graded concentrations in the range 0.2-100 μM (final DMF 0.1 % v/v). After 72 h of exposure, the cell biomass was determined by crystal violet staining, and the IC 50 value was determined as the concentration that caused 50 % inhibi-…”