Interactions between CuO NPs and PS: The release of copper ions and oxidative damage

Copper oxide nanoparticles (CuO NPs) can adversely affect lung health possibly by inducing oxidative damage through the release of copper ions. However, the migration and transformation processes of CuO NPs in lung lining fluid is still unclear, and there are still conflicting reports of redox reactions involving copper ions. To address this, we examined the release of copper ions from CuO NPs in simulated lung fluid supplemented with pulmonary surfactant (PS), and further analyzed the mechanisms of PS-CuO NPs interactions and the health hazards. The results showed that the phospholipid of PS was adsorbed on the particle surface, which not only induced aggregation of the particles but also provided a reaction environment for the interaction of PS with CuO NPs. PS was able to promote the release of ions from CuO NPs, of which the protein was a key component. Lipid peroxidation, protein destabilization, and disruption of the interfacial chemistry also occurred in the PS-CuO NPs interactions, during which copper ions were present only as divalent cations. Meanwhile, the contribution of the particle surface cannot be neglected in the oxidative damage to the lung caused by CuO NPs. Through reacting with biomolecules, CuO NPs accomplished ion release and induced oxidative damage associated with PS. This research was the first to reveal the mechanism of CuO NPs releasing copper ions and inducing lipid oxidative damage in the presence of PS, which provides a new idea of transition metal-induced health risk in human body.

Determination of the critical pH for unfolding water-soluble cod protein and its effect on encapsulation capacities

Hydrophobic polyphenols, with a variety of physiological activities, are often practically limited due to their low water solubility and chemical instability, among which curcumin (Cur) is a representative hydrophobic polyphenol. To improve Cur, the cod protein (CP)-Cur composite particles (CP-Cur) were successfully prepared using the pH-shift method, but this pH-shift method (7-12-7) required a higher pH, which limited application and increased cost. The critical pH of CP structure unfolding during pH-shift and its encapsulation effect on Cur were investigated in this paper. During the pH-shift process, the critical pH of the structural unfolding of CP was pH 10, and the degree of protein structure unfolding was higher, which was attributed to the increasing electrostatic repulsion, and the weakened hydrogen bond and hydrophobic interaction. The encapsulation efficiency of CP-Cur formed after pH 10-shift was higher than that formed after pH 9.8-shift, which increased by 22.17 %. At pH 9.8, the binding sites in CP reached saturation at the molar ratio of 10, while at pH 10 and 10.2, the binding sites in CP both reached saturation at the molar ratio of 14, also indicating that the protein treated with critical pH could bind more Cur. The binding between Cur and CP was mostly hydrophobic interaction, accompanied by hydrogen bonding and electrostatic interactions. The above results verified the necessity of critical pH in the experiment, indicating that critical pH could indeed improve the encapsulation effect and obtain a higher encapsulation efficiency. This work will help improve the large-scale application of hydrophobic functional substances in production.

The Bright and Dark Sides of Reactive Oxygen Species Generated by Copper–Peptide Complexes

Copper ions bind to biomolecules (e.g., peptides and proteins) playing an essential role in many biological and physiological pathways in the human body. The resulting complexes may contribute to the initiation of neurodegenerative diseases, cancer, and bacterial and viral diseases, or act as therapeutics. Some compounds can chemically damage biological macromolecules and initiate the development of pathogenic states. Conversely, a number of these compounds may have antibacterial, antiviral, and even anticancer properties. One of the most significant current discussions in Cu biochemistry relates to the mechanisms of the positive and negative actions of Cu ions based on the generation of reactive oxygen species, including radicals that can interact with DNA molecules. This review aims to analyze various peptide–copper complexes and the mechanism of their action.

Potent and selective PTP1B inhibition by a platinum(ii) complex: possible implications for a new antitumor strategy

Showing anti-proliferation activity against MCF7 cells better than cisplatin, a platinum(ii) complex, [PtL(DMSO)Cl], was found to potently and selectively inhibit protein tyrosine phosphatase 1B (PTP1B), a putative target for anticancer agents, suggesting a new possible anticancer strategy based on platinum drugs.

Synthesis and Characterization of FITC Labelled Ruthenium Dendrimer as a Prospective Anticancer Drug

Metallodendrimers-dendrimers with included metals-are widely investigated as biocompatible equivalents to metal nanoparticles. Applications can be expected in the fields of catalysis, as chemical sensors in molecular recognition and as anticancer drugs. Metallodendrimers can also mimic certain biomolecules, for example, haemoprotein in the case of using a dendrimer with a porphyrin core. In previous papers, we showed the promising anticancer effects of carbosilane ruthenium dendrimers. The present paper is devoted to studying biocompatibility and the cytotoxic effect on normal and cancer cells of carbosilane ruthenium dendrimers labelled with fluorescent probe fluorescein isothiocyanate (FITC). The addition of fluorescent probe allowed tracking the metallodendrimer in both normal and cancer cells. It was found that carbosilane ruthenium dendrimer labelled with FITC in concentration up to 10 µmol/L was more cytotoxic for cancer cells than for normal cells. Thus, FITC labelled carbosilane ruthenium dendrimer is a good candidate for diagnostic imaging and studying anticancer effects of metallodendrimers in cancer therapy.

Copper(II) complexes of N3O tripodal ligands appended with pyrene and polyamine groups: Anti-proliferative and nuclease activities

A series of tripodal ligands based on the 2-tert-butyl-4-R-6-phenol was synthesized, where R=aldehyde (HL¹), R=putrescine-pyrene (HL²) and R=putrescine (HL³). A dinucleating ligand wherein a putrescine group connects two tripodal moieties was also prepared (H₂L⁴). The corresponding copper complexes (1, 2, 3, and 4, respectively) were prepared and characterized. We determined the phenol's pKas in the range 2.47-3.93. The DNA binding constants were determined at 6×10⁶, 5.5×10⁵ and 2.7×10⁶ for 2, 3 and 4, respectively. The complexes display a metal-centered reduction wave at E_p^c,red=-0.45 to -0.5V vs. saturated calomel electrode, as well as a ligand-centered oxidation wave above 0.57V at pH7. In the presence of ascorbate they promote an efficient cleavage of DNA, with for example a concentration required to cleave 50% of supercoiled DNA of 1.7μM for 2. The nuclease activity is affected by the nature of the R group: putrescine-pyrene≈bis-ligating>putrescine>aldehyde. The species responsible for strand scission is the hydroxyl radical. The cytotoxicity of the complexes was evaluated on bladder cancer cell lines sensitive or resistant to cis-platin. The IC₅₀ of complexes 2 and 4 span over a short range (1.3-2μM) for the two cell lines. They are lower than those of the other complexes (3.1-9.7μM) and cis-platin. The most active compounds block the cell cycle at the G0/1 phase and promote apoptosis.

Synthesis and anticancer properties of ruthenium (II) complexes as potent apoptosis inducers through mitochondrial disruption

A new ligand MHPIP (MHPIP = 2-(1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its three ruthenium (II) complexes [Ru(N-N)₂(MHPIP)](ClO₄)₂ (N-N = phen: 1,10-phenanthroline 1; dmp = 2,9-dimethyl-1,10-phenanthroline 2; ttbpy = 4,4'-ditertiarybutyl-2,2'-bipyridine 3) were synthesized and characterized. The cytotoxic activity in vitro was studied by MTT method. The complexes 1-3 show moderate cytotoxic effects on the cell growth in HepG2 cells with an IC₅₀ value of 25.5 ± 3.5, 35.6 ± 1.9 and 27.4 ± 2.3 μM, respectively. The apoptosis was investigated with AO/EB and Annex V/PI staining methods and comet assay. The reactive oxygen species, mitochondrial membrane potential were investigated under a fluorescent microscope. Autophagy assay shows that the complexes can cause autophagy and up-regulate the expression of Beclin-1 protein. Additionally, the complexes inhibit the cell growth in HepG2 cells at G0/G1 phase, and the complexes can regulate the expression of caspase 3 and Bcl-2 family proteins. The studies demonstrate that the complexes induce apoptosis in HepG2 cells through DNA damage and ROS-mediated mitochondrial dysfunction pathways.

Self-assembled nanoparticles based on a cationic conjugated polymer/hyaluronan–cisplatin complex as a multifunctional platform for simultaneous tumor-targeting cell imaging and drug delivery

A multifunctional nanoparticle system based on a cationic conjugated polymer/hyaluronan–cisplatin complex for tumor-targeting cell imaging and drug delivery.

Mitochondrial and nuclear DNA dual damage induced by 2-(2′-quinolyl)benzimidazole copper complexes with potential anticancer activity

Complex 2 can induce nuclear and mitochondrial dual damage in HCT116 cells and can also induce apoptosis.

Coumarin centered copper(ii) complex with appended-imidazole as cancer chemotherapeutic agents against lung cancer: molecular insight via DFT-based vibrational analysis

Synthesis and structural characterization of the novel copper complex, DFT based vibrational analysis, DNA binding studies. In vitro cytotoxicity against A549 cancer cell lines and estimation of GSH, ROS, LPO levels, have been reported.