Flow cytometry and live confocal analysis for the evaluation of the uptake and intracellular distribution of FITC-ODN into HaCaT cells

SPANosomes as delivery vehicles for small interfering RNA (siRNA)

Nonionic surfactant vesicles, or SPANosomes (SPs), comprised of cationic lipid and sorbitan monooleate (Span 80) were synthesized and evaluated as small interfering RNA (siRNA) vectors. The SPs had a mean diameter of less than 100 nm and exhibited excellent colloidal stability. The SP/siRNA complexes possessed a slightly positive zeta potential of 12 mV and demonstrated a high siRNA incorporation efficiency of greater than 80%. Cryogenic transmission electron microscopy (cryo-TEM) imaging of the SP/siRNA indicated a predominantly core-shell structure. The SP/siRNA complexes were shown to efficiently and specifically silence expression of both green fluorescent protein (GFP) (66% knockdown) and aromatase (77% knockdown) genes in breast cancer cell lines. In addition, the cellular trafficking pathway of the SP/siRNA was investigated by confocal microscopy using molecular beacons as probes for cytosolic delivery. The results showed efficient endosomal escape and cytosolic delivery of the siRNA cargo following internalization of the SP/siRNA complexes. In conclusion, Span 80 is a potent helper lipid, and the SPs are promising vehicles for siRNA delivery.

Immunoliposomal systems targeting primary effusion lymphoma: in vitro study

Aims: To develop an appropriate liposomal formulation for gene delivery against primary effusion lymphoma (PEL), a herpesvirus HHV8-associated B-cell lymphoma. Materials & methods: Cationic, cationic PEGylated and cationic PEGylated anti-CD138 liposomes (ILp) linking a monoclonal antibody expressed on PEL cells were prepared by a thin layer evaporation method, followed by extrusion technique. The formulations were mixed with a model oligonucleotide to form the lipoplexes and tested on a BCBL-1 cell (a PEL cell line). The transfection efficiency was evaluated by flow cytometry and confocal laser scanning microscopy analysis. Results: Based on antigen–antibody interaction, ILp mediated a specific gene delivery as shown by a significant increase in the transfection rate and a localized internalization of the oligonucleotide, in comparison with cationic liposomes and cationic PEGylated liposomes. Conclusion: ILp could be proposed as effective carriers for oligonucleotide transfer in BCBL-1 cells. In vitro experimental results encourage us to further test the in vivo therapeutic potential of ILp for specific delivery of antitumoral agents.