Two generations of lipophilic pyrenyl functionalized poly(benzyl ether) dendrimers (P-1 and P-2) have been synthesized. The thermal properties of the two functionalized dendrimers have been investigated, and the pyrenyl group of the dendritic molecules encapsulated in the arene-ruthenium metalla-cage, [Ru-6(p-cymene)(6) (tpt)(2)(donq)(3)](6+) ([1](6+)) (tpt=2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq=5,8-dioxydo-1,4-naphthoquinonato). The host-guest properties of [P-1 subset of 1](6+) and [P-2 subset of 1](6+) were studied in solution by NMR and UV/Vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water-soluble host-guest systems was evaluated on human ovarian cancer cells.