A nonviral carrier for targeted gene delivery to tumor cells.
ABSTRACT In this study, we developed a nonviral, cationic, targeted DNA-carrier system by coupling SAINT/DOPE lipids to monoclonal antibodies. The two monoclonal antibodies used were both tumor specific, that is, MOC31 recognizes the epithelial glycoprotein EGP-2 present in carcinomas and Herceptin recognizes the HER-2/neu protein in breast and ovarian cancers. Coupling was performed under nonreducing conditions by covalent attachment. The coupling procedure appeared to be reproducible and the binding capacity of the antibody was not affected by linking them to the cationic lipid. Binding and transfection efficiency was assayed with target cells and nontarget cells. SAINT/DOPE lipoplexes as such appeared to be an effective transfection reagent for various cell lines. After coupling SAINT/DOPE to the monoclonal antibodies or F(ab)2 fragments, it was shown that the targeted MoAb-SAINT/DOPE lipoplexes preferably bound to target cells, compared to binding to the nontarget cells, especially for the Herceptin-SAINT/DOPE lipoplexes. More importantly, transfection of the target cells could also be improved with these targeted lipoplexes. In conclusion, we have shown that by using monoclonal antibody-coupled SAINT/DOPE lipoplexes cells targeted gene delivery can be achieved, and also a higher number of transfected target cells was seen.
Article: Targeted transfection increases siRNA uptake and gene silencing of primary endothelial cells in vitro--a quantitative study.[show abstract] [hide abstract]
ABSTRACT: Applications of small-interfering RNA (siRNA) call for specific and efficient delivery of siRNA into particular cell types. We developed a novel, non-viral targeting system to deliver siRNA specifically into inflammation-activated endothelial cells. This was achieved by conjugating the cationic amphiphilic lipid SAINT to antibodies recognizing the inflammatory cell adhesion molecule E-selectin. These anti-E-selectin-SAINT lipoplexes (SAINTarg) maintained antigen recognition capacity of the parental antibody in vitro, and ex vivo in human kidney tissue slices subjected to inflammatory conditions. Regular SAINT mediated transfection resulted in efficient gene silencing in human microvascular endothelial cells (HMEC-1) and conditionally immortalized glomerular endothelial cells (ciGEnC). However, primary human umbilical vein endothelial cells (HUVEC) transfected poorly, a phenomenon that we could quantitatively correlate with a cell-type specific capacity to facilitate siRNA uptake. Importantly, SAINTarg increased siRNA uptake and transfection specificity for activated endothelial cells. Transfection with SAINTarg delivered significantly more siRNA into activated HUVEC, compared to transfection with non-targeted SAINT. The enhanced uptake of siRNA was corroborated by improved silencing of both gene- and protein expression of VE-cadherin in activated HUVEC, indicating that SAINTarg delivered functionally active siRNA into endothelial cells. The obtained results demonstrate a successful design of a small nucleotide carrier system with improved and specific siRNA delivery into otherwise difficult-to-transfect primary endothelial cells, which in addition reduced considerably the amount of siRNA needed for gene silencing.Journal of Controlled Release 09/2009; 141(2):241-51. · 5.73 Impact Factor
Article: Pyridinium lipids with the dodecaborate cluster as polar headgroup: synthesis, characterization of the physical-chemical behavior, and toxicity in cell culture.[show abstract] [hide abstract]
ABSTRACT: We have prepared nine new dodecaborate cluster lipids with potential use in boron neutron capture therapy of tumors. This new generation of boron lipids is only singly negatively charged and consists of a pyridinium core with C(12), C(14), and C(16) chains as lipid backbone, connected through the nitrogen atom via a butylene, pentylene, or ethyleneoxyethylene linker to the oxygen atom on the dodecaborate cluster as headgroup. The lipids were obtained by nucleophilic attack of 4-(bisalkylmethyl)pyridine on the tetrahydrofurane, the dioxane, and a newly prepared tetrahydropyrane derivative, respectively, of closo-dodecaborate. All of these boron lipids are able to form closed vesicles in addition to some bilayers in the pure state and in the presence of helper lipids. The thermotropic behavior was found to be increasingly complex and polymorphic with increasing alkyl chain length. Except for two lipids, all lipids have low in vitro toxicity, and longer alkyl chains lead to a significant decrease in toxicity. The choice of the linker plays no major role with respect to their ability to form liposomes and their thermotropic properties, but the toxicity is influenced by the linkers in the case of short alkyl chains.Bioconjugate Chemistry 10/2009; 20(11):2190-8. · 4.93 Impact Factor
Article: Targeted transfection increases siRNA uptake and gene silencing of primary endothelial cellsJournal of Controlled Release 01/2010; 141:241-251. · 5.73 Impact Factor