Since malignancies have long been the second most common cause of death, it is important to explore new approaches to the treatment of cancer patients. In this context, we focused on a novel dual nanoparticle-based drug delivery platform. Specifically, we combined a fluorescently labelled carbosilane-ruthenium dendrimer FITC-CRD₁₃ possessing anticancer properties [1] with liposomes and investigated its cytotoxic effect on adhesive breast (MCF-7) and colon (HT-29) cancer cells with expected minimal effect on the viability of healthy human fibroblasts (BJ). Liposomes were prepared by a hydration method using zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC; 15mM). FITC-CRD₁₃ dendimer (0.15mM) was added during the hydration step of the lipid film. In order to reduce the size of liposomes and remove unencapsulated dendrimers, prepared samples were extruded through a 400 nm polycarbonate membrane and centrifuged thereafter.

Subsequently, the effect of DMPC+FITC-CRD₁₃ liposomes (0.5; 1; 2.5; 5; 10 µM; presumed dendrimer concentration) on the viability of selected cell lines was investigated using MTT assay [2]. Non-treated cells as 100% viability reference (negative control) and methanol (10µM, positive control) were used.

Treatment of the cells with DMPC+FITC-CRD₁₃ liposomes along the whole tested concentration range caused a viability drop to or below 80% for HT-29 and MCF-7 cancer cell lines. On the other hand, in BJ cell line, the viability was maintained at 80% or more. This suggests a selective effect of DMPC+FITC-CRD₁₃ liposomes on the cell viability, with a desirable toxicity towards cancer cells. For all three tested cell lines, a larger decrease in cell viability upon the 3h incubation time in comparison to 24h, was observed. Concentration dependent relation between the applied DMPC+FITC-CRD₁₃ and viability of cells was not significant, probably as a result of narrow concentration range chosen.

Obtained preliminary results will be used for further protocol optimization. Stability of DMPC+FITC-CRD₁₃ liposomes as well as the effect of lipid composition should be tested.