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Liposomes loaded with the rhenium compound (bis-dimethylsulfoxido-cis-tetrachlorodi-μ-pivalatodirhenium(III) (cis-Re2((CH3)3CCOO)2Cl4.2DMSO, I) and cisplatin in the molar ratio of 4:1 as well as those loaded only with I were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, dynamic light scattering and electronic absorption spectroscopy. The relative stability of liposomes loaded with I is reflected by a minimal change in the electronic absorption spectra over a period of 8 days whereas the stability of those loaded with both drugs is lower, which we ascribe to the formation of new Re-Pt species inside the liposomes. Furthermore, the investigations of the co-encapsulation effects on the anticancer activity of the Re-Pt system were undertaken. Importantly, the co-encapsulated liposomes exhibit synergistic or additive anticancer activities in vivo, e.g. introduction of these liposomes into tumor-bearing rats demonstrated their antianemic, nephro- and hepato-protecting effects. These liposomes, which are active in cancer treatment, protect the dirhenium compounds from hydrolysis and preserve the biological properties of the Re-Pt hybrid. This study reveals the importance of combined therapy in nanotechnology and medicine.

effects of the different modes of administration of dichlorotetra-μ-isobutyratodirhenium(ІІІ) -І -(in

The aim of the study. The aim of the work was to investigate in vivo anticancer activity of cis- and trans-diadamanthylcarboxylates of dirhenium(III) alone and together with cisplatin in form of nanobins.Materials and methods. Model of tumor growth, Guerin’s carcinoma; intraperitoneal administration of cisplatin, dirhenium(III) compounds in liposomes and of binary liposomes, containing both cytostatics; volumes and final weights of tumors were measured.Results. In vivo antitumor properties of two dirhenium(III) dicarboxylates with 1-adamantanecarboxylic acid moieties as ligands with cis- (I) and trans- (II) orientation of the carboxylic groups around a cluster fragment alone and together with cisplatin were presented; an attempt to understand differences in a possible mechanism of anticancer activity of the substances were undertaken. Antiradical and DNA-binding properties of I and II were the matter of consideration.Conclusions. Cis- and trans- compounds of dirhenium I and II had close antitumor activity in vivo with a little bit superiority of the cis- analog. Mechanisms of anticancer activity of I and II are different and may also include monofunctional adduct formation and subsequent interstrand cross-linking for the II substance, formation of protein-DNA cross-links, etc.