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Publications (9) View all
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Article: Sequence Defined Disulfide-linked Shuttle for Strongly Enhanced Intracellular Protein Delivery.
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ABSTRACT: Intracellular protein transduction technology is opening the door for a promising alternative to gene therapy. Techniques have to address all critical steps, like efficient cell uptake, endo-lysosomal escape, low toxicity, while maintaining full functional activity of the delivered protein. Here we present the use of a chemically precise, structure defined three-arm cationic oligomer carrier molecule for protein delivery. This carrier of exact and low molecular weight is combining good cellular uptake with efficient endosomal escape and low toxicity. The protein cargo is covalently attached by a bioreversible disulfide linkage. Murine 3T3 fibroblasts could be transduced very efficiently with cargo nlsEGFP, which was tagged with a nuclear localization signal. We could show subcellular delivery of the nlsEGFP to the nucleus, confirming cytosolic delivery and expected subsequent subcellular trafficking. Transfection efficiency was concentration-dependent in a directly linear mode and 20-fold higher in comparison with HIV-TAT-nlsEGFP containing a functional TAT transduction domain. Furthermore, ß-galactosidase as a model enzyme cargo, modified with the carrier oligomer, was transduced into neuroblastoma cells in enzymatically active form.Molecular Pharmaceutics 11/2012; · 4.78 Impact Factor -
Article: Intracellular fate of peptide-mediated delivered cargoes.
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ABSTRACT: Cell-penetrating peptides (CPPs) are promising tools for intracellular delivery. However, no consensus regarding their internalization mechanism has been reached within the scientific community. Although endocytosis seems to be the preferred internalization mechanism for most CPP-cargo complexes, examples of direct translocation have also been identified. In this review we go through the several ways of studying CPP-mediated cargo delivery in cells and the possible factors affecting the internalization pathways followed by these complexes. In addition, we analyze the CPP-mediated delivery of two relevant cargoes, namely quantum dots and nucleic acids, focusing on the internalization mechanism that they follow.Current pharmaceutical design 11/2012; · 4.41 Impact Factor -
Article: Design, synthesis and characterization of a new anionic cell-penetrating peptide: SAP(E).
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ABSTRACT: Cell-penetrating peptides (CPPs) are powerful tools to transport cell-impermeable cargoes into the cytoplasm without damaging the cell membrane. The vast majority of these peptides described to date share several features, among others, they are positively charged at physiological pH. In several cases a clear correlation between an increasing number of positive charges and internalization properties has been reported. Here, we describe what, to the best of our knowledge, is the first anionic CPP. This new compound SAP(E) internalizes into a range of cell lines with good efficiency and it shows low toxicity. We also report on the internalization mechanism. The discovery of this new class of CPP opens the way to the intracellular delivery of new molecular cargoes.ChemBioChem 03/2011; 12(6):896-903. · 3.94 Impact Factor -
Article: Building Cell Selectivity into CPP-Mediated Strategies
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ABSTRACT: There is a pressing need for more effective and selective therapies for cancer and other diseases. Consequently, much effort is being devoted to the development of alternative experimental approaches based on selective systems, which are designed to be specifically directed against target cells. In addition, a large number of highly potent therapeutic molecules are being discovered. However, they do not reach clinical trials because of their low delivery, poor specificity or their incapacity to bypass the plasma membrane. Cell-penetrating peptides (CPPs) are an open door for cell-impermeable compounds to reach intracellular targets. Putting all these together, research is sailing in the direction of the design of systems with the capacity to transport new drugs into a target cell. Some CPPs show cell type specificity while others require modifications or form part of more sophisticated drug delivery systems. In this review article we summarize several strategies for directed drug delivery involving CPPs that have been reported in the literature.Pharmaceuticals. 01/2010; -
Article: Comparison of four different particle sizing methods for siRNA polyplex characterization.
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ABSTRACT: The ability to reliably determine the size of siRNA polyplexes is the key for the rational design of particles and their formulation, as well as, their safe application in vivo. At the moment, no standard technique for size measurements is available. Each method has different underlying principles and hence may give different results. Here, four different analytical methods were evaluated for their suitability to analyze the characteristics of homogeneous and heterogeneous siRNA polyplexes: dynamic light scattering (DLS), atomic force microscopy (AFM), nanoparticle trafficking analysis (NTA), and fluorescence correlation spectroscopy (FCS). Three different siRNA polyplex compositions generated with different, precise, and hydrophobically modified oligoaminoamides were used in this study. All of the evaluated methods were suitable for analysis of medium sized, homogeneous siRNA polyplexes (∼120nm). Small particles (<40nm) could not be tracked with NTA, but with the other three methods. Heterogeneous polyplexes were generally difficult to analyze. Only by visualization with AFM, the heterogeneity of those polyplexes was observable. FCS was the only method suitable for measuring polyplex stability in 90% fetal bovine serum. Physico-chemical characteristics of polyplexes are important quality criterions for successful in vivo application and future formulation development. Therefore, a comprehensive analysis by more than one method is of particular importance.European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 10/2012; · 3.15 Impact Factor
