Journal of Cluster Science最新文献

Hückel’s (4n + 2) rule plays a vital role in rationalizing and predicting the aromaticity of annulenes (C_nH_n) and cyclic systems with delocalized electrons. The π-electron behavior in annulenes can be described by a two-dimensional (2D) jellium model, where π molecular orbitals (MOs) are treated as superatomic 2D orbitals (S, P, D …). Herein, heteroatoms (B, N, O) were introduced to replace C atoms in annulenes to extend the aromatic rule of monocyclic species beyond Hückel’s (4n + 2) framework. Electronic structures and aromaticity of C_nH_n (n = 4, 6, 8) and their heteroatom counterparts, B_nN_nH_2n and B_nO_nH_n (n = 2, 3, 4), were compared. C₆H₆, B₃N₃H_6, and B₃O₃H₃ with 6π electrons are aromatic with a superatomic closed-shell configuration of |S²|P⁴|, consistent with Hückel’s rule. Intriguingly, despite being 4n system, B₄N₄H₈/B₄O₄H₄ (8π) exhibit aromaticity, different from antiaromatic C₈H₈. Additionally, antiaromaticity of B₂N₂H₄/B₂O₂H₂ (4π) are weakened, exhibiting a new type of aromaticity. This is attributed to the significant splitting of the doubly degenerate superatomic P or D orbitals induced by the electronegativity difference between heteroatoms, which stabilizes the occupied orbitals (P_x, D_xy) relative to their unoccupied counterparts (P_y, D_x2-y2). This work enriches the fundamental understanding of aromaticity by proposing the 2nπ (n ≥ 2) aromaticity in hetero-monocyclic molecules.

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Breast cancer remains one of the most challenging cancers to confront women, and is considered one of the most lethal cancers to this day. Since the cancer was first identified, the search for the most effective treatment continues to evolve. A novel treatment strategy, nanomedicine, has presented a variety of materials that can be adaptively used as drug delivery systems. Myristicin, a natural substance obtained from nutmeg, has been noted for its ability to inhibit cancer cell growth. The present study aimed to explore the concurrent delivery of hyaluronic acid targeted Myristicin-encapsulated PLGA-PEG nanoparticles against breast cancer cells. The PLGA-PEG/M/HA NPs were analysed for their structural, physicochemical, and biological characteristics. The nanoparticles’ morphology and size distribution, examined through dynamic Light scattering and scanning microscopy, indicated that they had a spherical shape and an appropriate size range at 236.6 ± 1.98 nm. The PLGA-PEG/M/HA exhibited a significant ζ potential of -25.8 ± 1.23 mV, along with impressive drug loading of 8.2 ± 0.879% and 75 ± 3.12% of encapsulation efficiencies. The PLGA-PEG/M/HA demonstrated effective internalization, cumulative myristicin release (70 ± 3.18%), and dose-dependent cytotoxicity against MCF-7 cells (IC₅₀ at 182.76 ± 1.16 µg/ml). Moreover, free myristicin and HA-targeted myristicin-loaded nanoparticles showed no toxic effects on healthy cells (WRL-68). The PLGA-PEG/M/HA significantly triggered cytotoxic effects through the induction of 47.1 ± 2.67% of the early apoptosis and cell cycle arrest at G2/M phase. In contrast, the HA-targeted drug-loaded nanoparticles were notably more effective against cancerous cells compared to the bare myristicin. Our results suggest that the modified PLGA-PEG/M/HA nanoparticles could be a valuable platform for employing phytotherapy with a nano drug delivery system for breast cancer.

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Tamoxifen (Tam) has been shown to reduce estrogen receptor (ER)-positive breast cancer incidence. Limited data also suggest Tam may inhibit ER-negative lung cancer, though resistance and inflammation remain significant challenges. This study investigated the co-delivery of Tam and Celecoxib (Celx) via nano-formulations to enhance efficacy and reduce inflammation in lung cancer cells. Nano-formulations of Tam and Celx were synthesized and characterized by dynamic light scattering and transmission electron microscopy, revealing particle sizes of 94.2 ± 5.6 nm and 68.1 ± 6.5 nm, with low polydispersity and positive surface charges. Entrapment efficiencies were 85.6 ± 5.4% (Tam) and 94.2 ± 6.7% (Celx), with controlled drug release profiles. Co-treatment with nano-Tam and nano-Celx significantly inhibited A549 lung cancer cell proliferation in a dose- and time-dependent manner while sparing normal WI38 lung cells. The combination induced apoptosis, caused G0/G1 cell cycle arrest, and showed high cellular uptake (binding affinity: 94.9% for Tam; 80.2% for Celx). Apoptosis was supported by upregulation of TRAIL, DR4, DR5, Bax, and Caspase-8 expression levels, and downregulation of c-FLIP, JAK3, STAT3, AKT1, Bcl-2, TNF-α, IL-1β, and COX-2 levels. Molecular docking revealed moderate binding affinities of both drugs to anti-apoptotic and inflammatory targets, with Celx favoring hydrogen bonds and Tam relying on hydrophobic interactions. These findings suggest that nano-formulated Tam and Celx co-therapy may offer a promising approach to treat ER-negative lung cancer by enhancing apoptosis and reducing inflammation with minimal toxicity to normal cells.

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This study focuses on the synthesis of poly(2-vinylpyridine)-stabilized silver nanoparticles (P2VP-AgNPs) to be employed as a nanocarrier for ceftriaxone (CEF) in order to enhance its therapeutic efficacy. P2VP-AgNPs were synthesized via the chemical reduction method using P2VP as a stabilizer, silver nitrate as a silver source, and sodium borohydride as a reducing agent. Characterization of P2VP-AgNPs before and after the loading of CEF was performed using advanced analytical techniques. The CEF loading capacity was evaluated via UV-Vis spectrophotometry, and antimicrobial efficacy was assessed against six bacterial strains using the agar-well diffusion method. The inhibition efficacy of P2VP-AgNPs/CEF has doubled compared to direct application of CEF against six different bacterial strains, including gram-negative as well as gram-positive bacterial strains, which highlights the synergistic impact of this nanocarrier system. The synthesized P2VP-AgNPs exhibited a stable average size of 60.0 ± 2 nm and a zeta potential of + 40.0 ± 0.3 mV, which increased to 72.0 ± 2 nm and + 45.0 ± 0.3 mV, respectively, upon CEF loading. Over 87% of CEF was successfully loaded and released in a sustained manner, reaching 86% within 100 h. FTIR and PXRD analyses confirmed strong drug–nanoparticle interactions and reduced crystallinity, respectively. Antibacterial tests showed a > 2.5-fold increase in efficacy for P2VP-AgNPs/CEF compared to CEF alone, highlighting the potential of this nanocarrier for enhanced antibiotic delivery.

CO₂ hydrogenation to formic acid is a promising strategy for CO₂ mitigation, but requires high temperatures, pressure, additives and catalysts. This study reports the synthesis of Pd/ZnO obtained through the calcination of a palladium-modified zeolitic imidazolate framework (ZIF-8), applied in the CO₂ hydrogenation to formate, under mild reaction conditions. The crystal structure, crystallite size, microstrain, and morphological properties were characterized using XRD and TEM. Crystallite size and microstrain were evaluated by Scherrer and Williamson-Hall methods. The Pd/ZnO catalyst exhibited a hexagonal wurtzite ZnO structure and Pd in the face-centered cubic (fcc) phase, with small crystallite size and few imperfections in ZnO. The catalytic activity was evaluated for CO₂ hydrogenation in the aqueous phase, yielding 52.42 µmol of formate. The results suggest that Pd species are responsible for H₂ activation, while ZnO facilitates CO₂ activation. The ZIF-derived Pd/ZnO material demonstrates potential as catalyst for CO₂ conversion, contributing to environmental mitigation and development of carbon-neutral chemical processes.

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Glioblastoma (GBM) is a form of brain tumor, and the line of treatment includes the administration of temozolomide (TMZ). Due to the short life of TMZ, high doses are recommended, which leads to drug-induced adverse reactions. In this study, TMZ and Quercetin (QUE) loaded nanoemulsion was developed using a Quality by Design (QbD) approach for the treatment of GBM. The efficacy of TMZ and QUE was assessed through in silico studies, which revealed a synergistic effect of the drugs. Afterward, cellular assays using U87 MG cell lines demonstrated that the optimal ratio of TMZ to QUE (1:8 μg/mL) yielded a synergistic therapeutic effect. Thus, the ratio of TMZ to QUE was considered to design the formulation. The nanoemulsion was optimized by using a central composite rotatable design (CCRD). The prepared nanoemulsion was characterized by a droplet size of 84.91 ± 2.17 nm with a polydispersity index (PDI) value of 0.20 ± 0.01, zeta potential -7.7 ± 0.34 mV, % transmittance of 94.16 ± 8.05 %, etc. In vitro drug release and ex vivo permeation studies demonstrated that a dual drug-loaded nanoemulsion significantly improved drug permeation compared to the drug suspension. Furthermore, the pharmacokinetic studies also showed significant improvement in drug plasma concentrations for improved therapeutic efficacy. The nanoemulsion-treated groups also showed a significantly lower IC₅₀ value, indicating greater potency. Hence, the findings suggest that dual drug-loaded nanoemulsion could serve as an effective approach for treating GBM.

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The synthesis of silver nanoparticles with honey (H-AgNPs) has advanced by avoiding toxic reagents and harmful by products. Unlike other natural products, honey stands out for its practicality, eliminating the need for complex extraction processes and preservation steps. H-AgNPs possess distinct physicochemical properties, including optical and functional characteristics that can be enhanced by the presence of honey, making them promising candidates for applications in the pharmaceutical, chemical, and materials industries. This review begins with an examination of the synthesis parameters of H-AgNPs and the direct impact of variations in conditions on nanoparticle size, absorption spectra, and the main physicochemical characterization techniques employed to study these nanometals. Subsequently, the main applications of H-AgNPs were demonstrated in terms of their functional evaluations in biomedical fields and their contributions to materials engineering, thus demonstrating their promising potential observed in various in vitro and in vivo studies. The discussion also covers integration and the main challen ges encountered in scaling up production and advancing to clinical methods. However, there are still advantages to their use over other biosyntheses. Although H-AgNPs possess remarkable properties that make them suitable for a variety of applications, their synthesis continues to be hampered by limitations that go beyond current knowledge.

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Metal-doped endohedral borospherenes M@B₄₀ have attracted considerable attention since the discovery of the first boroshphenes B₄₀^−/0 in 2014. Systematical density functional theory investigations performed herein unveil the ground-state structures and coordination bonding patterns of a series of lanthanide-doped endohedral borospherenes Ln@B₄₀^0/+, including the doublet C_2v Ce@B₄₀⁺ (1, ²B₁), triplet C_2v Ce@B₄₀ (2, ³A₂), quartet C_2v Pr@B₄₀ (3, ⁴B₁), quintet C_2v Nd@B₄₀ (4, ⁵A₁), sextet C₂ Pm@B₄₀ (5, ⁶A), septet C_2v Sm@B₄₀ (6, ⁷A₂), octet D_2d Eu@B₄₀ (7, ⁸B₁), and octet C_2v Gd@B₄₀⁺ (8, ⁸A₂). Detailed principal interaction spin orbital (PISO) and adaptive natural density partitioning (AdNDP) bonding pattern analyses indicate that, with the number of unpaired α-electrons changing from n_α = 1, 2, 3, 4, 5, 6, 7, to 7 in the series, their coordination bonding energies decrease monotonically from E_c = 7.22, 6.93, 5.67, 4.85, 4.67, 4.29, 4.02, to 2.07 eV, respectively, with the dominating percentage contributions of the Ln 5d-involved PISOs to the overall E_c increasing almost monotonically from 66 to 83%, while the minor contributions of the Ln 4f-involved PISOs varying between 0.3% and 12.1% and that of Ln 6s-involved PISO pairs remaining basically unchanged in a narrow range between 6% and 8%. In average, the dominating 5d-invloved PISOs in Ln@B₄₀ contribute about 72.8% to the overall E_c, 19.3% higher than that (53.4%) of the 6d-involved PISOs in the newly reported actinide-doped An@B₄₀^+/0/−, while the minor 4f-involved PISOs in Ln@B₄₀ contribute about 6.1% to E_c, 15.7% lower than that (21.8%) of the 5f-invloved PISOs in An@B₄₀^+/0/−, quantitatively unveiling the differences in coordination bonding patterns between Ln@B₄₀^+/0 and An@B₄₀^+/0/−.

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Two novel Cu(I) complexes, [Cu(tdt)] (1) and [Cu₆(mtt)₆] (2), were synthesized using the solvothermal method with CuI and 1,3,4-thiadiazole-2-thiol (Htdt) or 4-methylthiazole-2-thiol (Hmtt). In 1, Cu(I) coordinates with the tdt ligand to form a new two-dimensional copper-sulfur based coordination polymer; tdt links binuclear copper clusters into a graphite-like layered structure. In 2, Cu(I) coordinates with the mtt ligand to form a copper-sulfur cluster-based compound; six mtt surround six copper atoms to construct an inverted triangular prismatic [Cu₆S₆] cluster molecule. Sulfur-sulfur interactions were observed in the structures of both compounds. We also tested the luminescent properties of the compounds: complex 1 emits red light at 632 nm under excitation, while complex 2 emits near-infrared photoluminescence at 833 nm in its solid-state photoluminescence spectrum.