Liposomes Containing Zinc-Based Chemotherapeutic Drug Block Proliferation and Trigger Apoptosis in Breast Cancer Cells

Platinum-based chemotherapeutic drugs are effective in killing malignant cells but often trigger drug resistance or off-target side effects. Unlike platinum, zinc is used as an endogenous cofactor for several cellular enzymes and may, thus, display increased biocompatibility. In this present study, we have rationally designed and synthesized two substituted phenanthro[9,10-d]imidazole-based ligands L1 and L2 with pyridine and quinoline substitution at the 2 position and their corresponding Zn(II) complexes; (L1)2Zn and (L2)2Zn, which are characterized by standard analytical and spectroscopic methods. (L2)2Zn, but not (L1)2Zn has intrinsic fluorescence, indicating its potential utility in imaging applications. To facilitate cellular uptake, we generated liposomal formations with a phospholipid DMPC (1,2-Dimyristoyl-sn-glycero-3-phosphocholine) through molecular self-assembly. These liposomal formulations Lip-(L1)2Zn and Lip-(L2)2Zn were able to enter breast cancer cells, induce DNA fragmentation, arrest the cell cycle at the G0/G1 phase, decrease proliferation, and promote apoptosis by activating the DNA damage response. Importantly, both Lip-(L1)2Zn and Lip-(L2)2Zn decreased the size of breast cancer cell-based spheroids, indicating they may be capable of suppressing tumor growth. Our work represents an important proof-of-concept exercise demonstrating that successful liposomal formation of phenanthro[9,10-d]imidazole-based Zn(II) complexes with inherent optical properties have great promise for the development of imaging probes and efficient anticancer drugs.

Aggregation-Induced Emission Active Donor-Acceptor Fluorophore as a Dual Sensor for Volatile Acids and Aromatic Amines

In the present work, a novel donor (D)-acceptor (A) fluorophore based on indeno-pyrrole derivative (PYROMe) has been utilized as a dual sensor for volatile acids and aromatic amines, where sensory responses were regulated by the aggregation-induced emission (AIE) property. The twisted structural framework of PYROMe, confirmed by crystal study, avoids closed cofacial encounter upon aggregation and aided with augmented rigidity via different noncovalent interactions that ultimately ensued restricted intramolecular rotation (RIR). Consequently, PYROMe exhibited AIE in THF/H₂O mixture along with bright solid-state emission. The accessibility of protonation at carbonyl site and feasible HOMO energy to accept electrons from aromatic amines during photoexcitation enabled PYROMe as a potential dual sensor. A thin film of PYROMe was utilized for the quantitative detection of volatile acids and aromatic amines, and the detection limit (DL) was found to be as low as 0.77 ppm and 6.04 ppb for trifluoroacetic acid (TFA) and aniline vapors, respectively. Beyond the established scopes of substituted indeno-pyrroles, the present study paves the way, for the first time, toward an AIE-driven dual-stimuli response in indeno-pyrrole based D-A fluorophores.

Gelation-driven selection in dynamic covalent C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C/CN exchange

Gelation-driven amplification of an optimal gel-forming constituent is demonstrated for dynamic covalent libraries based on CC/CN exchange, through selection of the components leading to the most stable gel.

Knoevenagel barbiturate derivatives bearing long alkyl chains were proven to form organogels in suitable solvents based on supramolecular interactions. Their reaction with imines allows for component exchange through CC/CN recombination. The effect of various parameters (solvents, chain length, and temperature) on the CC/CN exchange reaction has been studied. Mixing Knoevenagel compound K and imine I-16 in a 1 : 1 ratio generated a constitutional dynamic library containing the four constituents K, I-16, K′-16, and I′. The reversible exchange reaction was monitored by ¹H-NMR, showing marked changes in the fractions of the four constituents on sol–gel interconversion as a function of temperature. The library composition changed from statistical distribution of the four constituents in the sol state to selective amplification of the gel forming K′-16 constituent together with that of its agonist I′. The process amounts to self-organization driven component selection in a constitutional dynamic organogel system undergoing gelation. This process displays up-regulation of the gel-forming constituent by component redistribution through reversible covalent connections.

Microwave-Assisted Synthesis of Imidazo[4,5-f][1,10]phenanthroline Derivatives as Apoptosis Inducers in Chemotherapy by Stabilizing Bcl-2 G-quadruplex DNA

Herein, a series of imidazo[4,5-f][1,10] phenanthroline derivatives RPIP (PIP = imidazo [4,5-f][1,10] phenanthroline, R = NO₂, 1; CF₃, 2; Cl, 3; OH, 4) have been synthesized in yields of 82.3–94.7% at 100 °C under the irradiation of microwave. MTT assay has been utilized to evaluate the inhibitory activity (IC₅₀) of these compounds against the growth of various tumor cells, and the results revealed that these compounds, especially 1, exhibited excellent inhibitory activity against the growth of A549 cells with IC₅₀ of 15.03 μM. Moreover, it’s also confirmed that 1 can penetrate into the membrane of tumor cells and distribute in mitochondria when observed under microscopy, resulting apoptosis of tumor cells. The further studies showed that 1 can bind to bcl-2 G-quadruplex DNA, which demonstrated by the increase of melting point of bcl-2 G4 DNA in the presence of 1, as well as electronic titration and emission spectra. In a word, this kind of compound may develop as a potential apoptosis inducer in cancer chemotherapy via binding and stabilizing to the bcl-2 G-quadruplex DNA.

Carbazole modified salicylaldimines and their difluoroboron complexes: effect of the tert-butyl and trifluoromethyl terminal groups on organogelation and piezofluorochromism

Luminescent nanofibers were generated from nontraditional π-gelators based on salicylaldimines and their difluoroboron complex bearing tert-butyl carbazole and trifluoromethylbenzene.

Organogelation of cyanovinylcarbazole with terminal benzimidazole: AIE and response for gaseous acid

The intense emission of carbazole-modified benzimidazole in xerogel-based film can be quenched rapidly by gaseous acid due to protonation.

Electroluminescence and fluorescence response towards acid vapors depending on the structures of indole-fused phospholes

New isomers of phosphole heteroacenes 2-DIPO and 3-DIPO, in which indoles were fused with phospholes in different manners, have been synthesized.