Water-Soluble, Meso-Substituted Cationic Porphyrins—a Family of Compounds for Cellular Delivery of Oligonucleotides

Abstract

The delivery of oligonucleotides to appropriate intracellular compartments is crucial to their development as tools in gene function studies and as therapeutics. Here, we report the characterization of meso-substituted cationic porphyrins as a large class of water-soluble reagents for oligonucleotide delivery. These porphyrins form non-covalent complexes with single-stranded oligonucleotides and deliver these molecules into the nuclei of cell lines in culture. The porphyrins protect oligonucleotides from nuclease degradation, and delivery is unaffected by the presence of serum. Delivery capacity is dependent on the charge ratio and concentration of the oligonucleotide and porphyrin used to form the complex, on the chemical substituents of the oligonucleotide and on the identity of the cationic porphyrin. This class of molecules provides a versatile set of water-soluble delivery reagents that could contribute to the development of oligonucleotide drugs.

Axial Imidazole Binding Strengths in Porphyrinoid Cobalt(III) Complexes as Studied by Tandem Mass Spectrometry

“…Generally in the form of their metal complexes, they function, for example, as prosthetic groups in oxidation catalysts [2], reversible oxygen transporters [3], catalysts in hydrocarbon biosynthesis [4], are believed to be involved in the cellular delivery of oligonucleotides [5] and oligoribonucleotides [6], or they function as antennas and reactive centers in light harvesting systems [7].…”

“…As judged by its optical properties, its coordination properties are expected to be much more similar to those of diolchlorin complex [4]Co than those of porpholactone [2]Co. We have also included two pyrrole-modified porphyrins, morpholinochlorin [3]Co, and indaphyrin [5]Co in our study [43,44,45]. While free base morpholinochlorin 3 incorporating a sixmembered ring in the macrocycle structure is nearly as planar as a porphyrin/chlorin and it possesses chlorin-like optical properties [43], its coordination properties may be significantly different than those of porphyrins or chlorins.…”

“…This is because this morpholinochlorin possesses a much increased conformational flexibility than the parent porphyrin or chlorin [46]. Indaphyrin [5]Co is a severely non-planar porphyrinoid with an optical spectrum unlike that of any other porphyrin or chlorin [44,45]. Nonetheless, there are structural similarities to dioxoporphyrin [7]Co as both contain carbonyl groups at the (former) pyrrole β-positions.…”

Cyclodextrins and Oligonucleotide Delivery to Solid Tumours

“…Chemical procedures such as the use of cationic lipid reagents (Zelphati and Szoka, 1996), streptolysin O-mediated plasma membrane permeabilisation (Spiller and Tidd, 1995), an amphiphilic anionic peptide (Pichon et al, 1997) or cationic porphyrin derivative (Flynn et al, 1999) also result in the ONs being introduced directly into the cytosol, from where they migrate within minutes to the nucleus. Zelphati and Szoka (1996) demonstrated that there was no effect by Brefeldin A on movement of PS-ONs from the cytoplasm to the nucleus.…”

Cellular uptake of modified oligonucleotides enhanced by porphyrins studied by time-resolved microspectrofluorimetry and fluorescence imaging techniques

“…They thus represent promising class of medical drugs for healing various viral, malignant and genetic diseases [1,2]. Since polyanionic and hydrophilic oligonucleotides cannot diffuse easily through membrane into the cells, various penetration enhancers have been realized and studied as delivery agents, including water-soluble cationic porphyrins [3][4][5]. Due to Coulombic compensation of the negative charge, hydrophilicity of the oligonucleotides can be considerably reduced without preventing them from stronger and more specific interaction with targets inside the cells.…”