Anticancer, Antioxidant, and Catalytic Activities of Green Synthesized Gold Nanoparticles Using Avocado Seed Aqueous Extract.

Disposal of agricultural waste has a negative impact on the environment and human health and may contribute to the greenhouse effect. The field of nanotechnology could provide alternative solutions to upcycle agricultural wastes in a safer manner into high-end value products. Organic waste from plants contain biomaterials that could serve as reducing and capping agents in the synthesis of nanomaterials with enhanced activities for use in biomedical and environmental applications. Persea americana (avocado) is a fruit with a high nutritional value; however, despite its rich phytochemical profile, its seed is often discarded as waste. Therefore, this study aimed to upcycle avocado seeds through the synthesis of gold nanoparticles (AuNPs) and evaluate their anticancer, antioxidant, and catalytic activities. The biosynthesis of avocado seed extract (AvoSE)-mediated AuNPs (AvoSE-AuNPs) was achieved following the optimization of various reaction parameters, including pH, temperature, extract, and gold salt concentrations. The AvoSE-AuNPs were poly-dispersed and anisotropic, with average core and hydrodynamic sizes of 14 ± 3.7 and 101.39 ± 1.4 nm, respectively. The AvoSE-AuNPs showed excellent antioxidant potential in terms of ferric reducing antioxidant power (343.88 ± 0.001 µmolAAE/L), 2,2-diphenyl-1-picrylhydrazyl (128.80 ± 0.0159 µmolTE/L), and oxygen radical absorbance capacity (1822.02 ± 12.6338 µmolTE/L); significantly reduced the viability of Caco-2 and PC-3 cells in a dose-dependent manner; and efficiently reduced 4-nitrophenol (4-NP) to 4-aminophenol. This study demonstrated how avocado seeds, an agricultural waste, can be used as sources of new bioactive materials for the synthesis of AuNPs, which have excellent antioxidant, anticancer, and catalytic activities, showing AvoSE-AuNPs' versatility in various applications. In addition, the AvoSE-AuNPs exhibited good stability and recyclability during the catalytic activity, which is significant because some of the primary issues with the use of metallic NPs as catalysts are around the cost-effectiveness, recovery, and reusability of the catalyst.

Addressing the gaps in homeostatic mechanisms of copper and copper dithiocarbamate complexes in cancer therapy: a shift from classical platinum-drug mechanisms.

The platinum drug, cisplatin, is considered as among the most successful medications in cancer treatment. However, due to its inherent toxicity and resistance limitations, research into other metal-based non-platinum anticancer medications with diverse mechanisms of action remains an active field. In this regard, copper complexes feature among non-platinum compounds which have shown promising potential as effective anticancer drugs. Moreover, the interesting discovery that cancer cells can alter their copper homeostatic processes to develop resistance to platinum-based treatments leads to suggestions that some copper compounds can indeed re-sensitize cancer cells to these drugs. In this work, we review copper and copper complexes bearing dithiocarbamate ligands which have shown promising results as anticancer agents. Dithiocarbamate ligands act as effective ionophores to convey the complexes of interest into cells thereby influencing the metal homeostatic balance and inducing apoptosis through various mechanisms. We focus on copper homeostasis in mammalian cells and on our current understanding of copper dysregulation in cancer and recent therapeutic breakthroughs using copper coordination complexes as anticancer drugs. We also discuss the molecular foundation of the mechanisms underlying their anticancer action. The opportunities that exist in research for these compounds and their potential as anticancer agents, especially when coupled with ligands such as dithiocarbamates, are also reviewed.

Advances in Nanotechnology towards Development of Silver Nanoparticle-Based Wound-Healing Agents.

Since antiquity, silver-based therapies have been used in wound healing, wound care and management of infections to provide adequate healing. These therapies are associated with certain limitations, such as toxicity, skin discolouration and bacterial resistance, which have limited their use. As a result, new and innovative wound therapies, or strategies to improve the existing therapies, are sought after. Silver nanoparticles (AgNPs) have shown the potential to circumvent the limitations associated with conventional silver-based therapies as described above. AgNPs are effective against a broad spectrum of microorganisms and are less toxic, effective at lower concentrations and produce no skin discolouration. Furthermore, AgNPs can be decorated or coupled with other healing-promoting materials to provide optimum healing. This review details the history and impact of silver-based therapies leading up to AgNPs and AgNP-based nanoformulations in wound healing. It also highlights the properties of AgNPs that aid in wound healing and that make them superior to conventional silver-based wound treatment therapies.

Beyond DNA-targeting in Cancer Chemotherapy. Emerging Frontiers - A Review.

Modern anti-cancer drugs target DNA specifically for rapid division of malignant cells. One downside of this approach is that they also target other rapidly dividing healthy cells, such as those involved in hair growth leading to serious toxic side effects and hair loss. Therefore, it would be better to develop novel agents that address cellular signaling mechanisms unique to cancerous cells, and new research is now focussing on such approaches. Although the classical chemotherapy area involving DNA as the set target continues to produce important findings, nevertheless, a distinctly discernible emerging trend is the divergence from the cisplatin operation model that uses the metal as the primary active center of the drug. Many successful anti-cancer drugs present are associated with elevated toxicity levels. Cancers also develop immunity against most therapies and the area of cancer research can, therefore, be seen as an area with a high unaddressed need. Hence, ongoing work into cancer pathogenesis is important to create accurate preclinical tests that can contribute to the development of innovative drugs to manage and treat cancer. Some of the emergent frontiers utilizing different approaches include nanoparticles delivery, use of quantum dots, metal complexes, tumor ablation, magnetic hypothermia and hyperthermia by use of Superparamagnetic Iron oxide Nanostructures, pathomics and radiomics, laser surgery and exosomes. This review summarizes these new approaches in good detail, giving critical views with necessary comparisons. It also delves into what they carry for the future, including their advantages and disadvantages.

New Palladium(II) and Platinum(II) Complexes Based on Pyrrole Schiff Bases: Synthesis, Characterization, X-ray Structure, and Anticancer Activity.

New palladium (Pd)II and platinum (Pt)II complexes (C1-C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan-2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) are herein reported. The complexes (C1-C5) were characterized by FTIR, 1H and 13C NMR, UV-vis, and microanalyses. Single-crystal X-ray crystallographic analysis was performed for the two ligands (L1-L2) and a Pt complex. Both L1 and L2 belong to P21/n monoclinic and P-1 triclinic space systems, respectively. The complex C5 belongs to the P21/c monoclinic space group. The investigated molar conductivity of the complexes in DMSO gave the range 4.0-8.8 µS/cm, suggesting neutrality, with log P values ≥ 1.2692 ± 0.004, suggesting lipophilicity. The anticancer activity and mechanism of the complexes were investigated against various human cancerous (Caco-2, HeLa, HepG2, MCF-7, and PC-3) and noncancerous (MCF-12A) cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Apopercentage assays, respectively. C5 demonstrated strong DNA-binding affinity for calf thymus DNA (CT-DNA) with a binding constant of 8.049 × 104 M-1. C3 reduced cell viability of all the six cell lines, which included five cancerous cell lines, by more than 80%. The C5 complex also demonstrated remarkably high selectivity with no cytotoxic activity toward the noncancerous breast cell line but reduced the viability of the five cancerous cell lines, which included one breast cancer cell line, by more than 60%. Further studies are required to evaluate the selective toxicity of these two complexes and to fully understand their mechanism of action.

Peptide-functionalized nanoparticles for the selective induction of apoptosis in target cells.

AIM: The study developed a prohibitin (PHB) targeted nanotherapy for selective induction of apoptosis in target cells. METHODS: Gold nanoparticles (AuNPs) were bifunctionalized with adipose homing and proapoptotic peptides. The efficacy and mode of cell death induced by the AuNPs were investigated in vitro on three cancer cell lines. RESULTS: The antiproliferative activity of PHB-targeted bifunctionalized AuNPs was more pronounced on cells that express the PHB receptor, and demonstrated receptor-mediated targeting and selectivity. The bifunctionalized AuNPs induced cell death by apoptosis. CONCLUSION: The PHB-targeted nanotherapy under study could potentially be used for treatment of diseases that are characterized by overexpression of PHB. As such, further investigations will be conducted in vivo.

Antitumor activity of phenylene bridged binuclear bis(imino-quinolyl)palladium(II) and platinum(II) complexes.

Antitumor effects of a known bis(imino-quinolyl)palladium(II) complex 1 and its newly synthesized platinum(II) analogue 2 were evaluated against human breast (MCF-7) and human colon (HT-29) cancer cell lines. The complexes gave cytotoxicity profiles that were better than the reference drug cisplatin. The highest cytotoxic activities were pronounced in complex 2 across the two examined cancer cell lines. Both compounds represent potential active drugs based on bimetallic complexes.

Imino-phosphine palladium(II) and platinum(II) complexes: synthesis, molecular structures and evaluation as antitumor agents.

The imino-phosphine ligands L1 and L2 were prepared via condensation reaction of 2-(diphenylphosphino)benzaldehyde with substituted anilines and obtained in very good yields. An equimolar reaction of L1 and L2 with either PdCl2(cod) or PtCl2(cod) gave new palladium(II) and platinum(II) complexes 1-4. The compounds were characterized by elemental analysis, IR, (1)H and (31)P NMR spectroscopy. The molecular structures of 2, 3 and 4 were confirmed by X-ray crystallography. All the three molecular structures crystallized in monoclinic C2/c space system. The coordination geometry around the palladium and platinum atoms in respective structures exhibited distorted square planar geometry at the metal centers. The complexes were evaluated in vitro for their cytotoxic activity against human breast (MCF-7) and human colon (HT-29) cancer cells, and they exhibited growth inhibitory activities and selectivity that were superior to the standard compound cisplatin.

Dichlorido{N-[2-(diphenylphosphanyl)benzylidene]-2-methylaniline}palladium(II) acetonitrile monosolvate.

The title imino-phosphine compound, [PdCl2(C26H22NP)]·CH3CN, was prepared by reaction of N-[2-(diphenylphosphanyl)benzylidene]-2-methylaniline with dichlorido(cycloocta-1,5-diene)palladium(II) in dry CH2Cl2. The Pd(II) cation is coordinated by the P and N atoms of the bidentate chelating ligand and by two chloride anions, generating a distorted square-planar coordination geometry. There is a detectable trans influence for the chloride ligands. The methyl group present in this structure has an influence on the crystal packing.

Dichlorido{N-[(5-methyl-thio-phen-2-yl)methyl-idene]-2-(pyridin-2-yl)ethanamine-κ(2) N,N'}palladium(II).

In the title compound, [PdCl2(C13H14N2S)], the Pd(II) ion is coordinated by two N atoms of the chelating bidentate ligand and two chloride anions, giving rise to a distorted square-planar geometry. The methyl-substituted thio-phene arm and the pyridine ring are connected to the metal cation through N atoms to form a six-membered chelate ring with a boat conformation, making the complex stable.

Dichlorido{2-[(2,6-diethylphenyl)iminomethyl]quinoline-κ2N,N'}palladium(II) acetonitrile monosolvate.

The title complex, [PdCl(2)(C(20)H(20)N(2))]·CH(3)CN, was synthesized by the reaction of 2-[(2,6-diethylphenyl)iminomethyl]quinoline with dichlorido(cycloocta-1,5-diene)palladium(II) in dry CH(2)Cl(2). The Pd(II) ion is coordinated by two N atoms of the bidentate quinoline ligand and by two chloride anions, generating a distorted square-planar coordination geometry around the metal centre. There is a detectable trans influence for the chloride ligands. The crystal packing is characterized by π-π stacking between the quinoline rings. The use of acetonitrile as the crystallization solvent was essential for obtaining good-quality crystals.

Tricarbonyl-chlorido(η(5)-cyclo-penta-dien-yl)molybdenum(II).

The structure of the title compound, [Mo(C(5)H(5))Cl(CO)(3)], reveals a pseudo-square-pyramidal piano-stool coordination around the Mo(II) ion, which is surrounded by a cyclo-penta-dienyl ring, three carbonyl groups and a chloride ligand.

Dichlorido[2-(phenyl-imino-meth-yl)quinoline-N,N']palladium(II).

In the title complex, [PdCl(2)(C(16)H(12)N(2))], the Pd(II) ion is coordinated by two N atoms [Pd-N 2.039 (2), 2.073 (2) Å] from a bidentate ligand and two chloride anions [Pd-Cl 2.2655 (7), 2.2991 (7) Å] in a distorted square-planar geometry. In the crystal, π-π inter-actions between the six-membered rings of the quinoline fragments [centroid-centroid distances = 3.815 (5), 3.824 (5) Å] link two mol-ecules into centrosymmetric dimers.

Dichloridobis[(ferrocenyl-methyl-idene)(furan-2-ylmeth-yl)amine-κN]palladium(II).

The title compound, [Fe(2)Pd(C(5)H(5))(2)(C(11)H(10)NO)(2)Cl(2)], exhibits a square-planar geometry at the Pd(II) atom, which is determined by inversion-related chlorine and ferrocenyl-imine mol-ecules across a center of symmetry. The ferrocenyl-imine moieties are trans to each other.

Chlorido[2-({[2-(diphenyl-phosphan-yl)-benzyl-idene]amino}-meth-yl)thio-phene-κN,P]methyl-palladium(II).

In the title compound, [Pd(CH(3))Cl(C(24)H(20)NPS)], the Pd(II) ion is coordinated in a distorted square-planar environment which includes the P and N atoms of the bis-chelating ligand. The thio-phene ring is rotationally ordered, unlike in the majority of crystal structures containing this group.

Dichlorido{2-[(thio-phen-2-ylmeth-yl)imino-meth-yl]pyridine-κN,N'}palladium(II).

In the title compound, [PdCl(2)(C(11)H(10)N(2)S)], the Pd(II) ion is four-coordinated in a distorted square-planar environment by two N atoms of the chelating 2-[(thio-phen-2-ylmeth-yl)imino-meth-yl]pyridine ligand and two chloride anions. The thio-phene ring is rotationally disordered over two orientations in a 1:1 ratio. The crystal packing exhibits weak inter-molecular C-H⋯Cl and C-H⋯S hydrogen bonds.

Quinoline-2-carbaldehyde.

The title compound, C(10)H(7)NO, crystallizes with two almost planar mol-ecules (A and B) in the asymmetric unit (r.m.s. deviations = 0.018 and 0.020 Å). In the crystal, the A mol-ecules are linked by weak C-H⋯O inter-actions, thereby generating C(9) [001] chains. The B mol-ecules do not exhibit any directional bonding inter-actions.

Chlorido{N-[2-(diphenylphosphanyl)benz-ylidene]-2-(2-thienyl)ethanamine-κN,P}methylpalladium(II) dichloromethane hemisolvate.

In the title compound, [Pd(CH(3))Cl(C(25)H(22)NPS)]·0.5C(2)H(2)Cl(2), the Pd(II) atom is coordinated by the N,P-bidentate ligand, a methyl group and a chloride ion, generating a distorted square-planar PdCClNS coordination geometry, with the N and Cl atoms trans. The thio-phene ring is equally disordered over two orientations and the dichloro-methane solvent mol-ecule is disordered about an inversion centre.

Penta-carbon-yl{3-[(2S)-1-methyl-pyrrolidin-2-yl]pyridine}tungsten(0).

The title compound, [W(C(10)H(14)N(2))(CO)(5)], contains five carbonyl ligands and a nicotine ligand in an octa-hedral arrangement around the tungsten atom. The metal atom shows cis angles in the range 87.30 (16)-94.2 (2)°, and trans angles between 175.2 (2) and 178.1 (4)°. The W-CO bond trans to the pyridine N atom [1.987 (6) Å] is noticeably shorter than the others, which range between 2.036 (3) and 2.064 (3) Å, possibly due to the well-known trans effect. The distance between the W atom and the pyridine N atom is 2.278 (4) Å.

Bromido-1κBr-tricarbonyl-2κC-(2η-cyclo-penta-dien-yl)molybdenum(I)tungsten(I)(W-Mo).

The title compound, [WMoBr(C(5)H(5))(CO)(3)], is built up from a pseudo-square-pyramidal piano-stool coordination around the Mo atom, the important geometry being Mo-W = 2.6872 (7) Å, W-Br = 2.5591 (9) Šand Mo-W-Br = 158.35 (3)°.