Highly Emissive Self-Assembled BODIPY-Platinum Supramolecular Triangles

Abstract

Light-emitting supramolecular coordination complexes (SCCs) have been widely studied for applications in the chemical and biological sciences. Herein, we report the coordination-driven self-assembly of two highly emissive platinum(II) supramolecular triangles (1 and 2) containing BODIPY-based bridging ligands. The metallacycles exhibit favorable anticancer activities against HeLa cells (IC of 6.41 and 2.11 μM). The characteristic ∼570 nm fluorescence of the boron dipyrromethene (BODIPY) moieties in the metallacycles permits their intracellular visualization using confocal microscopy. Additionally, the BODIPY fluorophore is an excellent photodynamic agent, making the metallacycles as ideal therapeutics for photodynamic therapy (PDT) and chemotherapy. In vitro studies demonstrate that the combination indexes against HeLa cells are 0.56 and 0.48 for 1 and 2, respectively, confirming their synergistic anticancer effect. More importantly, these SCCs also exhibit superior anticancer efficacy toward cisplatin-resistant A2780cis cell line by combining PDT and chemotherapy, showing promise in overcoming drug resistance. This study exploits a multicomponent approach to self-assembled metallacages that enables design of effective theranostic agents wherein the platinum acceptors are toxic chemotherapeutics and the BODIPY donors are imaging probes and photosensitizers. Since each piece may be independently tuned, i.e., Pt(II) polypyridyl fragment swapped for Pt(II) phosphine, the activity may be optimized without a total redesign of the system.

Coordination‐Driven Self‐Assembly of Functionalized Supramolecular Metallacycles: Highlighted Research during 2010–2018

“…Recently, Yu, Huang, and Cook et al . constructed two highly emissive platinum(II) supramolecular triangles 56 and 57 containing BODIPY‐based bridging ligands through the coordination‐driven self‐assembly of a BODIPY ligand 53 with Pt(II) acceptors 54 or 55 in a 1 : 1 ratio in CH 2 Cl 2 /DMA at 60 °C for 24 h (Scheme ) . Confocal laser scanning microscopic (CLSM) investigation confirmed that the NPs containing the metallacycles 56 or 57 were internalized by human cervical cancer cells (HeLa) as witnessed by the observation that the HeLa cells exhibited strong intracellular fluorescence after incubation with the nanoparticles (NPs) containing the metallacycles 56 or 57 for 8 h (Figure ).…”

Boron Dipyrromethene Nano‐Photosensitizers for Anticancer Phototherapies

“…Zhou et al designed supramolecular triangles with vertices comprising novel Pt(II) complexes and edges comprising pyridyl‐functionalized BODIPY . In this design, the BODIPY cores within the triangles were used as PDT PSs, while the presence of Pt(II) complexes were for chemotherapy ( Figure a).…”

“…The concentration of the formulations was 1.00 × 10 −6 m . All panels reproduced with permission . Copyright 2018, American Chemical Society.…”

Harnessing the Photocatalytic Potential of Polypyrroles in Water through Nanointervension: Synthesis and Photophysical Evaluation of Biodegradable Polypyrrolic Nanoencapsulates

“…Moreover, the polypyrrolic photosensitizers have the capability of producing reactive oxygen species via the type two photosensitization process . In addition to that, they are insensitive to solvent, pH, and temperature finding their use in sensing, energy harvesting, water purification, theranostics, and photocatalysis …”

“…[9] In addition to that, they are insensitive to solvent, pH, and temperature finding their use in sensing, energy harvesting, water purification, theranostics, and photocatalysis. [10][11][12][13][14][15][16] The major drawback of these polypyrroles is that they are mostly hydrophobic in nature, which restricts their practical applicability. Multiple attempts have been made to improve the solubility of BODIPY and porphyrins through their conjugation/ adsorption on metal or metal oxide nanoparticles, [10,17,18] by preparing self-aggregated nanoparticles, [18] through encapsulation into polymers, etc.…”