Real-time analysis of uptake and bioactivatable cleavage of luciferin-transporter conjugates in transgenic reporter mice.
ABSTRACT Many therapeutic leads fail to advance clinically because of bioavailability, selectivity, and formulation problems. Molecular transporters can be used to address these problems. Molecular transporter conjugates of otherwise poorly soluble or poorly bioavailable drugs or probes exhibit excellent solubility in water and biological fluids and at the same time an enhanced ability to enter tissues and cells and with modification to do so selectively. For many conjugates, however, it is necessary to release the drug/probe cargo from the transporter after uptake to achieve activity. Here, we describe an imaging method that provides quantification of transporter conjugate uptake and cargo release in real-time in animal models. This method uses transgenic (luciferase) reporter mice and whole-body imaging, allowing noninvasive quantification of transporter conjugate uptake and probe (luciferin) release in real time. This process effectively emulates drug-conjugate delivery, drug release, and drug turnover by an intracellular target, providing a facile method to evaluate comparative uptake of new transporters and efficacy and selectivity of linker release as required for fundamental studies and therapeutic applications.
SourceAvailable from: Albert K. Beck[Show abstract] [Hide abstract]
ABSTRACT: β(3) -Octaarginine chains were attached to the functional groups NH and CO2 H of the antibacterial fluoroquinolones ciprofloxacin (→1) and enrofloxacin (→2), respectively, in order to find out whether the activity increases by attachment of the polycationic, cell-penetrating peptide (CPP) moiety. For comparison, simple amides, 3-5, of the two antimicrobial compounds and β(3) -octaarginine amide (βR8 ) were included in the antibacterial susceptibility tests to clarify the impact of chemical modification on the microbiological activity of either scaffold (Table). Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.Chemistry & Biodiversity 02/2015; 12(2):179-193. DOI:10.1002/cbdv.201400456 · 1.80 Impact Factor
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ABSTRACT: A highly versatile and step-economical route to a new class of guanidinium-rich molecular transporters and evaluation of their ability to complex, deliver and release siRNA are described. These new drug/probe delivery systems are prepared in only two steps, irrespective of length or composition, using an organocatalytic ring-opening co-oligomerization of glycerol-derived cyclic carbonate monomers incorporating either protected guanidine or lipid side chains. The resultant amphipathic co-oligomers are highly effective vehicles for siRNA delivery, providing an excellent level of target protein suppression (>85%). These new oligocarbonates are non-toxic at levels required for cell penetration and can be tuned for particle size. Relative to the previously reported methyl(trimethylene)carbonate (MTC) scaffold, the ether linkage at C2 in the new transporters markedly enhances the stability of the siRNA:co-oligomer complexes. Both hybrid co-oligomers, containing a mixture of glycerol- and MTC-derived monomers, and co-oligomers containing only glycerol monomers are found to provide tunable control over siRNA complex stability. Based on a glycerol and CO2 backbone, these new co-oligomers represent a rapidly tunable and biocompatible siRNA delivery system that is highly effective in suppressing target protein synthesis.Molecular Pharmaceutics 01/2015; 12(3). DOI:10.1021/mp500581r · 4.79 Impact Factor
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ABSTRACT: We report a simple, effective method to assess the cytosolic delivery efficiency and kinetics of cell-penetrating peptides using a pH-sensitive fluorescent probe, naphthofluorescein.Chemical Communications 12/2014; 51(11). DOI:10.1039/C4CC09441G · 6.72 Impact Factor