Journal of Nanoparticle Research最新文献

There is a growing need for multifunctional biomaterials to serve both structural stabilization and biological function in bone regeneration. In this work, we developed hydroxyapatite–gelatin composites that combine dual-drug delivery with bioactivity and cytocompatibility. Macroporous composites were fabricated using a foam-templated precipitation route, and dual drugs were loaded (rifampicin, an antimicrobial, and indomethacin, an anti-inflammatory). Release kinetics exhibited a triphasic release profile with ~ 65–70% release taking place in the first 96 h, followed by sustained release until 240 h. The initial release kinetics showed the drug was released according to the Higuchi model; the profile shifted towards diffusion–swelling as confirmed by the Korsmeyer–Peppas fitting. When immersed in simulated body fluid in vitro, apatite was uniformly deposited within 7 days, indicating mineralization capacity was preserved. Cytocompatibility studies using MG-63 osteoblast-like cells showed 90% viability or greater for all extract concentrations, exceeding ISO 10993–5 criteria. These results demonstrate the composites as a multifunctional bone filler platform, enabling localized delivery of antimicrobial and anti-inflammatory drugs, bioactivity, and cytocompatibility.

The adsorption behavior of 2-(4-oxo-2-thioxothiazolidin-3-yl)-N-(p-tolyl)acetamide (OTA) on silver nanoparticles was studied using surface enhanced Raman scattering (SERS) and density functional theory (DFT). The presence of various inactive Raman modes in SERS is due to polarizability variations in the presence of metal. Negative adsorption energy shows strong bonding between silver and OTA. Structural characteristics represent charge transfer of the metal cluster that underwent bonding with OTA. The hardness and chemical potential of OTA are 1.6527 and −4.4407 eV, while these in OTA1 (C=O near to Ag₆) are 1.1789 and −3.7449 eV, and the reduction in these values shows a strong shared interaction with OTA and Ag. The υC=O are observed in SERS at all concentrations and show up and down changes in frequencies, giving interaction with Ag and orientation changes with concentration changes. Since OTA is an acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitor, docking with 1GQR and 6ASM gives binding affinities of −8.5 and −7.8 kcal mol⁻¹. Molecular dynamics (MD) simulations indicate that docked OTA remained stable, maintained by H-bonds. When OTA was near Ag₆, changes were observed in electron density at several places.

This study conducts a comprehensive first-principles density functional theory analysis on pristine PtS₂ monolayers and those doped with O, Se, Te, Si, P, and Cl atoms. Geometry optimization reveals that different doping induces ordered changes in bond lengths and lattice parameters. Electronic structure calculations indicate that doping effectively tunes the bandgap from semiconducting to near-metallic states, inducing pronounced orbital hybridization at the Fermi level. Optical property analysis (real and imaginary dielectric functions, absorption coefficients, and reflectivity) reveals the differences in the response of doped systems in the UV, VIS, and NIR wavelength bands. Furthermore, the O- and P-doped systems were investigated systematically. The bandgap and main absorption/reflection peaks undergo reversible redshift and blueshift when bi-directional strain is applied to the O- and P-doped systems. The study provides a comprehensive and compact theoretical basis for the applications of tunable photovoltaic devices, IR detectors, and flexible strain sensors based on PtS₂.

Superparamagnetic iron oxide nanoparticles (SPIONs) are promising in cancer nanomedicine due to their magnetic responsiveness and biocompatibility, yet their clinical use is hindered by instability, oxidation, and lack of active targeting. Here, we report a multi-stimuli-responsive nanocarrier that integrates magnetic responsiveness from the SPION core, folic acid–mediated active targeting, and pH-sensitive release. Oleic acid (OA)–stabilized SPIONs (OCION) were coated with a Brij–folic acid (BF) conjugate, and quercetin (QCT), a poorly soluble anticancer drug, was encapsulated in the hybrid lipid bilayer (HLB). The BF to OCION ratio was optimized, and the 6:1 formulation yielded uniform, monodisperse nanoparticles OCION@BF with excellent colloidal stability for 30 days and preserved superparamagnetic properties. The optimized OCION@BF achieved 95% encapsulation efficiency and enabled sustained, pH-responsive QCT release, with faster liberation under acidic conditions. Biological assays confirmed that blank OCION@BF was non-toxic, while QCT@OCION@BF significantly improved anticancer efficacy against MCF-7 cells, showing a ~ 2.4-fold lower IC₅₀ than free QCT. Collectively, OCION@BF combines exogenous (magnetic), endogenous (folate-targeting), and microenvironmental (pH-responsive) stimuli responsiveness, representing a versatile platform for efficient delivery of poorly soluble drugs and a promising candidate for targeted cancer therapy.

Graphical Abstract

Ballistic aggregates (BAs) have long been used in astrophysics to model interstellar dust, particularly for analyzing their light scattering and absorption characteristics. In this work, we extend the application of BA structures into the plasmonic domain by investigating their optical response at the nanoscale. Using the discrete dipole approximation (DDA), we numerically simulate the extinction and absorption behavior of 50 nm radius metal nanoparticles (Al, Ag, Au) arranged in BA, BAM1, and BAM2 configurations. Our results confirm that the optical properties of these clusters are strongly influenced by porosity, number of monomers, and the refractive index of the embedding medium. Notably, we identify a transition wavelength, below which extinction increases with porosity, while above it, the trend reverses. We also observe a redshift in surface plasmon resonance (SPR) with decreasing porosity and increasing cluster size, offering broad tunability of the extinction spectrum. The near-field analysis further reveals significant field enhancement due to interparticle coupling. These findings suggest that nanoscale BA-type clusters could serve as viable candidates for plasmon-enhanced light absorption in photovoltaic applications.

The rapid control of opportunistic pathogens—through both their detection and elimination—is crucial to mitigate health risks, especially for immunocompromised individuals. In this study, silver nanoparticles (AgNPs) were synthesized via a simple and environmentally friendly approach, using ascorbic acid reduction under medical steam sterilizer conditions, and evaluated as a dual-function colloidal platform that integrates antimicrobial activity and surface-enhanced Raman scattering (SERS)-based pathogen identification. Structural characterization using scanning electron microscopy, zeta potential, UV–Vis spectroscopy, and X-ray diffraction confirmed uniform morphology, high colloidal stability, and crystallinity. The AgNP substrates provided robust and reproducible SERS signals, achieving an analytical enhancement factor of approximately 10⁶ at concentrations down to 1 nM, with sample-to-sample variability below 5%. The antimicrobial assays demonstrated rapid biocidal activity, with > 99% (R > 2) of Escherichia coli, Staphylococcus aureus, and Candida albicans eliminated within 1 h, and significant bactericidal efficacy (R > 6) maintained over 48 h. Importantly, the controlled antimicrobial interaction facilitated the release of intracellular components, yielding more consistent and distinctive spectral profiles that enhanced species-level discrimination. Principal component analysis (PCA) revealed clear separation among pathogen-specific spectral clusters, while a linear support vector machine (SVM) classifier achieved 95.7% accuracy, confirming strong discriminative capability. Overall, this study serves as a proof of concept for a dual-function colloidal AgNP platform, synthesized via an accessible autoclave-assisted green approach, that combines antimicrobial action with SERS-based pathogen identification in a simple and reproducible format.

Alzheimer’s disease (AD) therapies remain limited by poor blood–brain barrier (BBB) penetration and modest cognitive recovery. This study aimed to develop and evaluate transferrin-conjugated S-adenosylmethionine-loaded citric acid-stabilized superparamagnetic iron oxide nanoparticles (Tf-SAMe-CA-SPIONs) as a targeted nanoplatform for brain delivery. SPIONs were synthesised by co-precipitation and optimised using a design of experiments approach. The formulation was characterised for physicochemical, magnetic, and structural attributes, and its BBB permeability and neuroprotective efficacy were assessed using in vitro and zebrafish AD models. The optimised SPIONs displayed hydrodynamic diameters of 58–71 nm (PDI < 0.33). Following citric acid stabilisation, the particle size increased to 111.3 nm (PDI 0.347, zeta potential –20.08 mV), while transferrin–SAMe conjugation further enlarged the particles to around 196.4 nm with a zeta potential of –28.28 mV. XRD confirmed the magnetite spinel crystalline structure, and VSM analysis verified their superparamagnetic behaviour with a saturation magnetisation (Ms) of 52 emu/g. The formulation demonstrated a high drug-loading efficiency of 72% and exhibited transferrin receptor–mediated cellular uptake in vitro. In vivo, treatment with the formulation led to significant cognitive enhancement in zebrafish, as evidenced by increased correct entries, reduced latency, and prolonged reward chamber occupancy, outperforming currently available formulations. Tf–SAMe–CA–SPIONs demonstrated excellent stability, efficient brain-targeted delivery, and marked improvement in cognitive function. By integrating targeted delivery, magnetic responsiveness, and neuroprotective effects, this multifunctional nanoplatform offers a promising theranostic strategy for the treatment and management of Alzheimer’s disease.

Graphical Abstract

The development of high-capacity and easily separable adsorbents is crucial for efficient dye wastewater treatment. Herein, a magnetic Fe₃O₄@ZIF-67 nanocomposite was synthesized via a facile in situ method to enhance its separation and recovery capabilities. The characterization results confirmed the successful synthesis of this nanocomposite. The batch adsorption experiments demonstrated that its adsorption capacity reached as high as 949.5 mg·g⁻¹. This process can be well described by the Langmuir and pseudo-second-order models, indicating it is a single-layer chemical adsorption. The thermodynamic studies revealed the adsorption to be spontaneous and endothermic. This work not only presents Fe₃O₄@ZIF-67 as a highly efficient and recyclable adsorbent for malachite green (MG) but also validates the strategy of constructing magnetic MOF-based composites for practical environmental remediation.

The development of safer treatment alternatives for cancer and other chronic illnesses still calls for innovation. Chemopreventive agents (e.g., quercetin, QR) are often sought after for therapeutic and palliative care. However, poor aqueous solubility, chemical instability, and low bioavailability limit their use. With this in mind, we evaluated the potential for synergistic effects among cholesterol, surfactants, and non-covalent polymer coatings (polyethylene glycol and chitosan) in transferosomes. Dispersions of L-α-phosphatidylcholine and cholesterol were prepared by the thin-film hydration method and ultrasonication. Non-ionic, anionic, and cationic surfactants: poloxamer-407, sodium deoxycholate (SDC), and cetyltrimethylammonium bromide (CTAB), respectively, were added to regulate the deformability of the cholesterol-containing lipid bilayers. CTAB-QR-transferosomes released the highest amount of QR, 86.50 ± 0.54%, in 24 h, with a particle size of 284.54 ± 28.4 nm, zeta potential of 20.2 ± 10.6 mV, viscosity of 11.19 ± 4.96 cP, entrapment efficiency of 99.1 ± 0.1%, and drug loading capacity of 13.56 ± 0.01%. The QR-loaded lipid-based nanocarriers with the cholesterol/CTAB intra-membrane modulators were then separately coated with polyethylene glycol (PEG) and chitosan to test for a potential synergistic effect of the polymers on membrane interactions with HepG2, A594, and U937 cell lines. The polymer-coated cholesterol/surfactant-regulated lipid vesicles did not make a statistically significant contribution to cytotoxicity against HepG2 cells compared with free quercetin. However, the synergy between CTAB and PEG resulted in a greater increase in cytotoxicity against A594 cells than the CTAB/Chitosan combination. None of the polymeric coatings provided an additional increase in efficacy against U937 cells compared with uncoated transferosomes containing cholesterol and CTAB. To our knowledge, this is the first exploration of possible synergistic contributions between antagonistic intra-membrane modulators and polymer coatings on transferosomes to evaluate potential benefits of enhanced cytotoxicity against cancerous cells in vitro.

Graphical abstract