Bioinorganic Chemistry and Applications最新文献

Background: Polydopamine (PDA) exhibits superior adhesion and notable bioactive characteristics, such as antimicrobial activity and favorable biocompatibility with host tissues, while zinc oxide (ZnO) nanoparticles (NPs) have proved to provide antibacterial and remineralizing properties. Combining these benefits, PDA with ZnO NP (PDA@ZnO NP) could offer superior antimicrobial activity, adhesion, and biocompatibility, possibly making it a promising alternative to conventional sealers like AH Plus (Dentsply Sirona, Germany) and zinc oxide eugenol (ZOE) (Prevest DenPro Limited, India).

Aim: An effort has been made in this study to assess and compare the physicochemical properties, sealing efficiency, antibacterial potential, and biocompatibility of PDA@ZnO NP-based root canal sealer with conventional AH Plus and ZOE sealers.

Materials and methods: The PDA@ZnO NP sealer was synthesized and characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and zeta potential analysis. Physicochemical properties, including setting time, flow, pH, radiopacity, sealing ability, and biological properties such as biocompatibility and antibacterial property against Prevotella intermedia, were assessed and compared with AH Plus and ZOE sealers. The sealer penetration was evaluated using confocal laser scanning microscopy (CLSM). A comparison among the 3 groups was conducted using ANOVA and then by Tukey's honestly significant difference (HSD) test for post hoc multiple comparisons.

Results: The PDA@ZnO NP sealer exhibited superior dentinal tubule penetration, enhanced adhesion, and strong antibacterial properties compared with AH Plus and ZOE; statistical tests showed significant differences among groups for sealing ability and antibacterial activity (p < 0.05). Cytotoxicity assays indicated that PDA@ZnO NP and AH Plus had comparable cytocompatibility (pairwise p > 0.05), while ZOE showed a transiently lower viability at 24 h (84.3%, p < 0.05 vs. control).

Conclusion: The outcomes of this study highlighted that the PDA@ZnO NP sealer demonstrated superior sealing ability, enhanced dentinal tubule penetration, and favorable cytocompatibility, comparable to AH Plus and more favorable than ZOE at early timepoints. It also showed strong antibacterial efficacy and improved physicochemical properties. These findings suggest that PDA@ZnO NP sealer may serve as a promising alternative for clinical endodontic applications, potentially contributing to improved treatment outcomes and long-term success in root canal therapy.

This study reports the synthesis and evaluation of novel nanohybrids comprising multi-walled carbon nanotubes (MWCNTs) coated with mesoporous silica CNTs (MSCNTs) to facilitate uniform silver nanoparticles (AgNPs) formation. The extract of Angelica gigas Nakai processed by hot-melt extrusion (HAE) was employed as a green stabilizing and reducing agent for AgNP synthesis. The resulting MSCNT formulations were comprehensively characterized by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) mapping, and X-ray diffraction (XRD). We investigated the influence of HAE concentration on AgNPs formation and distribution on MSCNTs and subsequently evaluated their synergistic effects against methicillin-resistant Staphylococcus aureus (MRSA). Antibacterial activity was assessed through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), alongside biofilm formation inhibition and disruption activities. Our findings revealed that higher concentrations of HAE significantly improved the uniform distribution of AgNPs on MSCNTs, leading to enhanced antimicrobial activity against MRSA. Furthermore, the MSCNT-HAE formulations effectively inhibited and disrupted MRSA biofilm formation, a key mechanism of antibiotic resistance. Beyond their antibacterial properties, the cytotoxicity of these nanohybrids was evaluated against both normal human keratinocytes (HaCaT) and triple-negative breast cancer (MDA-MB-231) cells. Further investigations into apoptosis, utilizing cell staining and flow cytometry (FACS), were conducted on MDA-MB-231 cells. The results demonstrated that the incorporation of HAE significantly enhanced the selective cytotoxic effects against cancer cells, promoting apoptosis. This research highlights the potential of green-synthesized AgNPs on MSCNTs as a promising dual-action therapeutic strategy for combating antibiotic-resistant bacterial infections and cancer.

Schiff bases are imine derivatives widely recognized for their structural versatility and ability to coordinate transition metals, giving rise to compounds with remarkable physicochemical and biological properties. Over the last decade, numerous studies have reported their diverse applications, ranging from antimicrobial, antioxidant, and anticancer activities to roles as catalysts, fluorescent sensors, and photovoltaic materials. While previous reviews have focused on specific aspects-such as biomedical activity, catalytic transformations, or luminescent sensing-there is still a lack of an integrative perspective that connects these different areas. In this review, we provide a comprehensive analysis of recent advances in Schiff bases and their metal complexes, emphasizing their multifunctionality at the interface of bioinorganic chemistry and materials science. We highlight how metal coordination enhances biological activity, how structural design expands the scope of asymmetric catalysis, how Schiff-based fluorophores are emerging as versatile luminescent sensors, and how aromatic and metal-Schiff derivatives contribute to the development of next-generation photovoltaic devices. By offering this transversal vision, the article aims to bridge fragmented knowledge and outline future research directions to fully exploit the potential of Schiff bases in medicine, catalysis, sensing, and sustainable energy.

The multifunctional properties of a new oxovanadium(V) complex [VO(L) (5-Cl-8-HQ)] containing a Schiff base derived from L-arginine and salicylaldehyde and 5-chloroquinolin-8-ol, were investigated in this study. The complex was characterized using elemental analysis, cyclic voltammetry, powder X-ray diffraction, as well as FTIR, UV-Vis, and ¹H NMR spectroscopies. The electrochemical function of the complex as a sensor for pyridoxine detection showed a quasireversible behavior with an electrochemical rate constant of k _e  = 0.133 s^-1 in the linear range of detection of 1.0 × 10^-8 to 1.0 × 10^-4 mol·L^-1, with a limit of detection of 4.24 × 10^-8 mol·L^-1. The complex also exhibited good activity as a potential anticancer agent in regard to the MDA-MB-231 breast cancer cell line, with IC₅₀ = 35.09 ± 0.03 μg/mL with a steep hill slope of 2.575 in the dose-response curve, suggesting a sensitive cellular response to the complex, indicating promising anticancer potential. UV-Vis spectroscopy remains the method of choice for stability studies conducted under physiological conditions. The results showed a progressive complex breakdown in the cell culture medium at 37°C over 96 h, implying that its biological activity could be a mixture of the degradation products of the complex. The complex also showed antimicrobial effects at concentrations of 10 and 20 ppm against Staphylococcus aureus, Enterococcus faecalis, and Aspergillus niger, with the diameter of the inhibition zone (IZ) increasing with increasing complex concentration. The combination of these electrochemical sensing properties with the dual therapeutic potential as an anticancer and antimicrobial agent places this class of vanadium complexes in a versatile position for further development in both analytical and medicinal fields.

Complexes [RuCp(PPh₃)₂(HdmoPTA)][PtCl₄] (1), [RuCp(PPh₃)₂-µ-dmoPTA-1κP:2κ²-N,N'-Pt(κ² C,O-CH₂N(CH₃)CHO)][PtCl₄] (2), [RuClCp(PPh₃) (HdmoPTA)]₂[PtCl₄] (3), and [RuClCp(PPh₃)-µ-dmoPTA-1κP:2κ²-N,N'-Pt(κ² C,O-CH₂N(CH₃)CHO)]₂[PtCl₄] (4) have been synthesized and characterized by NMR, IR, and crystal structure of 2 was obtained by single crystal X-Ray diffraction. Antiproliferative activity of 1 was assessed against six human solid tumor cell lines and compared to cisplatin as a standard, showing GI₅₀ values in the submicromolar range.

Human metapneumovirus (HMPV) is a respiratory pathogen of global concern, particularly affecting infants, the elderly, and immunocompromised individuals. Despite its prevalence, no targeted antiviral therapies are currently approved. In this study, we employed a structure-guided computational strategy to repurpose clinically approved metal-based drugs as potential HMPV inhibitors. A curated chemical library was screened against the HMPV fusion protein (PDB ID: 5WB0) using high-accuracy molecular docking, followed by molecular dynamics (MD) simulations (2000 ns), binding free energy calculations, and pharmacophore modeling. Top-ranked compounds-Auranofin, silver sulfadiazine, and gallium nitrate-exhibited superior binding affinities (ΔG_binding: -68.5 to -62.7 kcal/mol), stable protein-ligand complexes (RMSD: 2.1-2.4 Å), and consistent interaction profiles when benchmarked against known antivirals ribavirin and favipiravir. Quantum chemical descriptors derived from density functional theory (DFT) and molecular electrostatic potential (MESP) mapping confirmed their favorable electronic properties, including optimal HOMO-LUMO gaps and total energy stability. Furthermore, ADMET predictions revealed acceptable oral bioavailability, low predicted toxicity, and renal clearance profiles, though known risks such as gallium accumulation were acknowledged. This integrative study highlights the potential of repurposed metallodrugs as novel anti-HMPV agents, offering a rational and cost-effective path toward therapeutic advancement.

In this study, zirconium oxide nanoparticles (ZrO₂ NPs) were synthesized using astaxanthin (AST) rich extract (AZ) and subsequently conjugated with multiwalled carbon nanotubes (MWCNTs) (AZM) and functionalized with folic acid (FA) (FAZM) to develop a cancer-targeting nanocomposite with enhanced anticancer efficacy. The physicochemical properties of the synthesized materials were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), electrophoretic light scattering (ELS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). FAZM exhibited the highest antioxidant activity, with IC₅₀ values of 822.78 μg/mL against ABTS and 320.70 μg/mL against DPPH free radicals. Biocompatibility assessments revealed that FAZM exhibited little cytotoxicity in normal human skin cells and demonstrated improved hemocompatibility, as confirmed by a hemolysis assay. Furthermore, FAZM significantly inhibited the proliferation of MDA-MB-231 breast cancer cells, inducing apoptosis and exhibiting potent cytotoxic effects (IC₅₀: 115.84 μg/mL). These findings suggest that FA and MWCNTs enhance the cancer-targeting capability of AZ while maximizing its selective cytotoxicity against cancer cells. This study highlights that FA-functionalized MWCNT-conjugated ZrO₂ NPs are a promising nanoplatform as an AST delivery system for targeted cancer therapy.

Ten organometallic complexes of the general formula [M(p-cymene)thi_CΛNMeIm]NO₃ (M = Ru, Os; MeIm = 1-methylimidazole, thi = 4-phenylthiazole) differing in their substituents on the 4-phenylthiazole scaffold were prepared and characterized by standard analytical methods. The antiproliferative activity of the compounds was investigated in human lung adenocarcinoma (A549), colon adenocarcinoma (SW480), and human ovarian teratocarcinoma (CH1/PA-1) cell lines. IC₅₀ values were in the low micromolar range with two exceptions. Additionally, the cytotoxicity of selected compounds was determined in the HCT116 colon carcinoma cell line in both 2D (monolayer) and 3D (multicellular spheroid) cultures. For selected compounds, the capacity of ROS induction was investigated in SW480 cells. Cellular accumulation experiments, as well as studies regarding stability and reactivity in aqueous solution, were performed, providing conclusive explanations for the observed differences in cytotoxicity. Furthermore, amino acid and DNA interaction studies were performed to elucidate aspects of the mechanism of action. The obtained insight into the antiproliferative activity in multicellular spheroids compelled us to perform in vivo studies, revealing the unexpected therapeutic efficacy of an in vitro inactive complex.

[This retracts the article DOI: 10.1155/2022/1401995.].

This study investigates the green synthesis of zinc oxide nanoparticles (ZnO NPs) using the aqueous extract of the aquatic plant Spirodela polyrhiza (greater duckweed) and evaluates their multifunctional properties. The ZnO NPs were synthesized via a sustainable method and characterized using UV-visible spectroscopy, TEM, FESEM, EDX, FTIR, and XRD analyses. UV-visible spectroscopy confirmed the formation of ZnO NPs with a characteristic absorption peak at ∼349 nm. TEM and FESEM analyses revealed spherical and nonspherical particles ranging from 20 to 70 nm. The antimicrobial activity of ZnO NPs was assessed against three bacterial strains (Escherichia coli, Staphylococcus aureus, and Bacillus subtilis) and three fungal strains (Aspergillus niger, Penicillium chrysogenum, and Candida albicans). Notably, B. subtilis showed a maximum inhibition zone of 18 mm at 100 mg/mL, while A. niger exhibited the highest antifungal response with a zone of 22 mm and an activity index (AI) of 1.15, indicating comparable or superior activity to ketoconazole at higher concentrations. Molecular docking simulations using the crystal structure of B. subtilis YmaH (Hfq) protein (PDB ID: 3HSB) revealed strong noncovalent interactions with Zn atoms of the NPs, particularly involving HIS57 and LEU26 residues. Additionally, ZnO NPs demonstrated a noteworthy photocatalytic degradation (90.4%) of methylene blue dye under sunlight exposure. These results highlight the potential of S. polyrhiza-mediated ZnO NPs for use in antimicrobial therapies and environmental remediation applications.