Gene Delivery to Cancer Cells with Metafectene and Its Derivatives: Nanoparticle Tracking Analysis of Lipoplexes

Abstract

To identify optimal non-viral vectors for suicide gene therapy of cancer, we compared the transfection activities of Metafectene (M) and its derivatives in HSC-3 oral squamous cell carcinoma, and HeLa cervical carcinoma cells. We determined the size distribution of the vectors and their complexes with DNA (lipoplexes).The cells were used at 80% confluence. pCMV.Luc, expressing luciferase was complexed with different volumes of M, M-Pro (MP), M-Easy (ME) (Biontex) and Fugene HD (FHD) (Roche) and incubated with the cells for 4 h. 48 h after transfection, the cells were lysed and the transfection activity was assayed using the Luciferase Assay System (Promega). The size distribution of the reagents and their lipoplexes was determined using a NanoSight.The mean sizes of the reagents were 165 nm (M), 181 nm (MP), 155 nm (ME) and 230-306 nm (FHD). The mean sizes of lipoplexes prepared with 2 μl reagent and 1 μg DNA were 282±2 nm (M), 293±30 nm (MP), 264±8 nm (ME) and 311±7 nm (FHD). The transfection activity in both cell lines decreased in the order ME>MP>M>>FHD. In HeLa cells, luciferase activity achieved with ME was 680-fold higher than that with FHD, and with HSC-3 cells, it was 83-fold higher. The low activity of FHD was surprising, as previous experiments had produced much higher activities. Transfection activity of ME in HeLa cells was 40-fold higher than in HSC-3 cells. Lipoplexes prepared with 0.5, 1 and 1.5 μl ME and 1 μg DNA had multiple peaks in particle analysis, whereas lipoplexes made with 2 μl ME were homogeneous.The mechanisms of the resistance of HSC-3 cells to transfection are not known. A uniform size distribution of lipoplexes may contribute to higher transfection activity.