Self-Assembled Novel BODIPY-Based Palladium Supramolecules and Their Cellular Localization

Abstract

Four new palladium metal supramolecules with triangular/square architectures derived from boron dipyrromethane (BODIPY) ligands were synthesized by self-assembly and fully characterized by H andP NMR, electrospray ionization mass spectrometry, and single-crystal X-ray diffraction. These supramolecules were more cytotoxic to brain cancer (glioblastoma) cells than to normal lung fibroblasts. Their cytotoxicity to the glioblastoma cells was higher than that of a benchmark metal-based chemotherapy drug, cisplatin. The characteristic green fluorescence of the BODIPY ligands in these supramolecules permitted their intracellular visualization using confocal microscopy, and the compounds were localized in the cytoplasm and on the plasma membrane.

Self-Assembly of Bodipy-Derived Extended π-Systems

“…Supramolecules based on palladium complex, 51 and Bodipy ligands 54 and 55 (Figure 19d) have been used for intracellular visualization with the help of confocal microscopy. 109 The triangular/square-shaped supramolecules (54/55¢51) exhibited higher cytotoxicity towards brain cancer cells than the normal cells. The supramolecules (54/55¢51) were found to be stable in phosphate-buffer saline, NaCl, KCl solutions and also in physiological conditions.…”

Antitumor Activity of a Unique Polymer That Incorporates a Fluorescent Self-Assembled Metallacycle

“…Guanosine triphosphate (GTP) was utilized as a competitive ligand to study the disassembly of the metallacycle M via fluorescence spectroscopy. 4a A significant fluorescence quenching was observed after incubating an aqueous solution of M with GTP (Figure S18), suggesting that GTP is a suitable donor for PhenPt and can disassemble the metallacycle. Next, the metallacycle M was gradually added to a solution containing calf-thymus DNA (ctDNA) and the relative viscosity ( η/η o ) of the resulting solution was increased, indicating the formation of ctDNA/Pt coordination complex (Figure S19).…”

“…This subsequently helps to trace the delivery and release of the organometallic drug in vitro and in vivo . 4 Nevertheless, for biomedical applications the stability of the SCCs in a physiological environment needs to be improved, because the metals ( e.g . Fe, Cu and Zn) and amino acids present in blood can potentially dissociate the SCCs and, thereby, causing side effects as well as erroneous imaging results.…”

Metal-based BODIPY derivatives as multimodal tools for life sciences

“…Up to now, many established pharmacophores have been coupled to BODIPY derivatives in order to study their uptake and intracellular localization (Figure 4). Self-assemblies of metal-based BODIPY derivatives have also been recently reported as potential theranostics [43][44][45]. The neutral analogue of cisplatin 2.1-2 was demonstrated to induce DNA damages in ovarian carcinoma cells, associated with a 100-times reduced activity with respect to cisplatin [46].…”