RSC Publishing


Publishing

 

Cover image for Dalton Transactions, select for current issue

Dalton Transactions

The international journal for inorganic, organometallic and bioinorganic chemistry




Paper

Article citation: Jonathan F. Arambula, Dalton Trans., 2009, DOI: 10.1039/b912089k


Gadolinium texaphyrin (Gd-Tex)-malonato-platinum conjugates: Synthesis and comparison with carboplatin in normal and Pt-resistant cell lines

Jonathan F. Arambula, Jonathan L. Sessler, Mark E. Fountain, Wen-hao Wei, Darren Magda and Zahid H. Siddik


The synthesis of a new PEG-solubilized gadolinium texaphyrin (Gd-Tex) conjugate containing a malonate-Pt(NH3)2 moiety is described. The effect of the tumor localizing Gd-Tex macrocycle on platinum activity was evaluated in cell culture. The malonate moiety, analogous to that present in carboplatin, is expected to release an aquated Pt(NH3)2 species under physiological conditions. The half-life in phosphate-buffered saline was found to be ca. 3 days at room temperature, and the hydrolytic product released from the conjugate was collected and confirmed as Pt-based by flameless atomic absorption spectrophotometry. Anti-proliferative activity was tested using A549 human lung cancer and A2780 human ovarian cancer cell lines. In both cell lines, the activity of the Gd-Tex conjugate was found to be similar to that of carboplatin. Efficacy against a Pt-resistant ovarian cell line greater than that displayed by carboplatin was also observed.

Graphical abstract image for this article  (ID: b912089k)