Ruthenium carboranyl complexes with 2,2'-bipyridine derivatives for potential bimodal therapy application

Ruthenium complexes of carboranyl ligands offer the possibility of dual action (chemo + radiotherapy) that might result in significant clinical benefits. In that frame, we describe herein the development of ruthenium-carboranyl complexes bearing bipyridyl derivatives with the general formula [3-CO-3,3-{?2-4,4'-R2-2,2'-bipy}-closo-3,1,2-RuC2B9H11] (R = CH3RuCB1or R = CH2OH,RuCB2). Both compounds crystallized in the monoclinic system, showing the expected three-legged piano stool structure. The ruthenacarboranes are stable in cell culture media and were tested against two cell lines that have shown favorable clinical responses with BNCT, namely melanoma (A375) and glioblastoma (U87).RuCB1shows no cytotoxic activity up to 100 µM whileRuCB2showed moderate activity for both cell lines. Cell distribution assays showed thatRuCB2presents high boron internalization that is proportional to the concentration used indicating thatRuCB2presents features to be further studied as a potential anticancer bimodal agent (chemo + radiotherapy).