Search Results (104)

Nanotechnology has emerged as a promising strategy in restorative dentistry and endodontics due to the physicochemical and biological properties of nanomaterials. This narrative review aimed to critically analyze the current applications of nanomaterials in restorative dentistry and endodontics, highlighting their mechanisms of action, biological properties, and translational potential. A literature search was performed in the PubMed/MEDLINE database using combinations of MeSH terms and free keywords related to nanomaterials and dental applications. Studies published in English within the last twenty years and addressing restorative or endodontic applications were considered. After screening and eligibility assessment, 69 studies were included in the descriptive analysis. The findings indicate that nanomaterials have been investigated in preventive strategies, adhesive systems, restorative materials, intracanal medicaments, endodontic sealers, vital pulp therapy, and regenerative formulations. In restorative dentistry, nanoparticles such as silver nanoparticles, nano-hydroxyapatite, amorphous calcium phosphate, bioactive glass nanoparticles, and chitosan-based systems showed favorable antimicrobial, remineralizing, and material-enhancing properties. In endodontics, silver and chitosan nanoparticles showed potential for intracanal disinfection and biofilm disruption, while chlorhexidine, zinc, and bioactive glass nanoparticles enhanced the antimicrobial activity and sealing ability of endodontic sealers. In addition, magnetic nanoparticles, mesoporous silica nanoparticles, and hydroxyapatite nanoparticles presented promising applications in regenerative endodontics and vital pulp therapy. However, most of the available evidence is still based on in vitro studies, with limited long-term clinical validation. Overall, nanotechnology offers potential experimental advantages for improving preventive, restorative, and endodontic therapies; however, its successful clinical translation remains strictly dependent on overcoming critical biosafety barriers and addressing long-term toxicity concerns. Full article

Magnetic polymeric microspheres are pivotal solid-phase carriers in chemiluminescence enzyme immunoassays (CLEIA). However, their practical clinical application is frequently hindered by non-specific adsorption, irreversible aggregation, and the intrinsic susceptibility of exposed outermost Fe₃O₄ nanoparticles to oxidation. To overcome these critical bottlenecks, we rationally engineered highly original monodisperse P(St-MMA)@Fe₃O₄@P(St-MMA) sandwich-structured microspheres. The bespoke amphiphilic outer shell acts as an impenetrable shield against hydration and oxidation, while maintaining a topologically size-matched mesoporous network (average pore size of 13.11 nm) for optimal antibody anchoring. Strikingly, this architecture ensures exceptional long-term colloidal stability, completely preventing macroscopic agglomeration for over six months in buffer solutions. When evaluated in a carcinoembryonic antigen (CEA), CLEIA, our microspheres achieved an ultra-low limit of detection (LOD) of 0.055 ng·mL⁻¹ and high analytical recovery (93.37–108.25%). In a head-to-head comparison with industry-standard commercial magnetic beads, the engineered microspheres delivered stronger chemiluminescent signals and lower background noise, demonstrating excellent intra-assay (CV < 4.37%) and inter-assay (CV < 10%) precision. This work establishes a scalable, highly stable materials platform that effectively resolves the persistent oxidation limitations, holding immense practical importance for next-generation ultrasensitive clinical in vitro diagnostics. Full article

Micro- and nano-container-based self-healing coatings have emerged as a promising strategy for the long-term conservation of cultural heritage artifacts, including metals, stone, organic matter, and construction materials. These coatings incorporate microcapsules or nanocapsules with tailored shell and core materials, enabling autonomous release of healing agents or corrosion inhibitors in response to damage. For metallic artifacts, benzotriazole@mesoporous silica nanoparticles (BTA@MSN) microcapsules achieve selective pH-responsive release, reaching 77% at pH 9.0 and 42% at pH 5.0, effectively mitigating localized corrosion. Temperature-adaptive poly(methyl methacrylate-co-methacrylic acid) (PMMA-MA)/MgO microcapsules exhibit controlled rupture rates, with a 75% reduction at elevated temperatures, enhancing crack repair efficiency by approximately 5%. Organic artifacts, such as wooden or paper manuscripts, benefit from clove oil nanocapsules, which increase tensile strength by 43.5% and fracture toughness by 101.9%, with only 2.91% weight loss over 7 days compared to 33.1% for unencapsulated oil. Advanced fabrication methods—including microfluidics, Pickering emulsions, and multi-core systems—enable high encapsulation efficiency (up to 73.5%), uniform particle size, and repeatable healing. Multi-stimuli responsiveness (pH, temperature, light, magnetic fields) and biobased, environmentally friendly materials further enhance adaptability and sustainability. In this review, “self-healing” is defined broadly to include both physical crack repair and autonomous restoration of protective functions. Overall, self-healing micro/nanocapsule coatings provide a highly controllable, efficient, and durable solution for active heritage protection, representing a shift from passive to intelligent conservation strategies. Furthermore, a systematic comparison of different capsule systems is provided to clarify their respective advantages and limitations. Overall, hybrid systems exhibit the most balanced performance, while inorganic nanocontainers offer superior stability and controlled release, and polymeric capsules enable rapid healing but limited reusability. Full article

Nanoparticle-catalysed microwave-aided multicomponent reactions (MCRs) have been demonstrated to be competent and environmentally benign tools for the quick synthesis of a wide spectrum of fused heterocyclic systems. The distinctive physicochemical properties of nanoparticles, including a substantial surface area, readily modifiable surface functionality, and heightened catalytic activities, when coupled with microwave irradiation, have enabled a marked improvement in reaction rates, product yields, and selectivity compared to conventional heating methods. This review highlights recent advancements in microwave-assisted MCRs facilitated by diverse nanomaterials, such as magnetic nanocatalysts, metal and metal oxide nanoparticles, mesoporous silica systems, and nanohybrids. It emphasises catalyst design, catalytic efficacy, scope, recyclability, and alignment with green chemistry principles in both solvent-free and aqueous environments, as well as the utilisation of recyclable catalysts. In summary, microwave-assisted multi-component reactions catalysed by nanoparticles are ecofriendly and versatile methods for the sustainable synthesis of such fused heterocycles containing bioactive pyridine, pyrazole, phenazine, pyrimidine, pyran, imidazole, and relevant pyridine derivatives, possessing potential in medicinal and material chemistry. Full article

Magnetic nanoparticles, with their excellent biocompatibility and biodegradability, serve as ideal materials for constructing targeted drug delivery systems. Iron oxide (Fe₃O₄) nanoparticles, controllably prepared via methods such as solvothermal synthesis, can be combined with mesoporous silica to construct magnetically steerable nanorobots. Such robots enable efficient drug loading and precise delivery. To address challenges in the treatment of Inflammatory Bowel Disease (IBD), including the significant side effects of systemic drugs and the low oral bioavailability and poor colonic targeting of novel food-derived drugs (e.g., capsaicin with anti-inflammatory activity), this study designed capsaicin-loaded iron oxide-mesoporous silica composite nanorobots (Cap-M@mSbots). Driven by a rotating gradient magnetic field of up to 80 mT, Cap-M@mSbots achieve large-scale emergent collective locomotion, with a maximum collective locomotion velocity reaching 180.7 μm/s, and are capable of long-distance movement overcoming millimeter-scale obstacles. This system can be actively propelled to colonic lesion sites under magnetic guidance, achieving targeted drug enrichment and sustained release, thereby offering a novel strategy for the targeted therapy of IBD. Full article

Oxaliplatin (OXA) is a chemotherapeutic agent that suffers from poor pharmacokinetics and off-target toxicity. To enable controlled OXA release, we engineered a multi-functional iron oxide nanoparticle (IONPs) drug delivery system, based on pH-responsive mesoporous Fe₃O₄ (Fe₃O₄@MSN-NH₂) nanoparticles (NPs), conjugated with folic acid (FA) for receptor-mediated targeting and guided by a magnetic robot platform (MRP) under simulated physiologically relevant dynamic circulation/flow system. For FA-conjugated NPs (Fe₃O₄@MSN-NH₂/FA), ~29.73% OXA loading was achieved compared to ~10.3% in controls (Fe₃O₄@MSN-NH₂/OXA), quantified by ICP-OES. Under dynamic circulation flow over 48 h, MRP enhanced pH-responsive OXA release (quantified by HPLC-UV), reaching ~92% and 88% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) at pH 5, versus 47% and 40% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) without MRP, demonstrating precise control in acidic tumor-mimicking conditions. MRI relaxometry exhibited strong T2-weighted contrast (T2 = 0.015 s at 50 μg/mL for Fe₃O₄@MSN-NH₂/FA/OXA), confirming theranostic potential. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) studies revealed variable Folate receptor alpha (FOLR1) expression among colorectal cancer cell lines (Caco2, SW620, SW48, and T84), with Caco2 demonstrating high levels. MTT assays indicated selective targeting of FOLR1-positive cells by FA-functionalized NPs (Fe₃O₄@MSN-NH₂/FA). This multi-functional drug delivery system integrates targeted delivery, MRP release, and real-time imaging, offering a promising technique for precision oncology. Full article

Background: Chemodynamic therapy (CDT) and photothermal therapy (PTT) based on nanomaterials have garnered widespread attention in cancer treatment. However, most single-modal nanotherapeutics suffer from limited therapeutic efficacy. Methods: Herein, a magnetic mesoporous composite nanoparticle, Fe₃O₄@MSN@PDA-HA-FA, is successfully fabricated, with Fe₃O₄ nanoparticles as the magnetic core; mesoporous silica nanoparticles (MSNs) as the mesoporous shell; and dopamine hydrochloride (DA·HCl), hyaluronic acid (HA), and folic acid (FA) as the functional ligands. Results: Notably, this composite serves as both an efficient photothermal converter and a chemodynamic promoter, enhancing hydroxyl radical (·OH) generation and improving PTT efficacy. Under near-infrared (NIR) light irradiation, Fe₃O₄@MSN@PDA-HA-FA exhibits high photothermal conversion and heat transfer efficiencies. The Fe²⁺ ions in Fe₃O₄ enable a Fenton reaction-mediated conversion of endogenous hydrogen peroxide (H₂O₂) into ·OH for CDT. Additionally, the MSNs provide a substantial drug-loading capacity, while the HA and FA provide additional surface functionalities that can modulate the nano-bio interactions and improve colloidal stability. Conclusions: In vitro experiments validate the synergistic therapeutic efficacy of PTT, CDT, and chemotherapy. This study demonstrates that Fe₃O₄@MSN@PDA-HA-FA exhibits antitumor efficacy, laying a promising foundation for its potential clinical translation in cancer treatment. Full article

Alkaline treatment in 0.2 and 0.4 M NaOH solutions successfully generated controlled mesoporosity into ZSM-5 (Zeolite Socony Mobil-5) zeolite, resulting in average mesopore diameters of approximately 15 and 25 nm, respectively, while preserving the crystalline structure of the zeolite framework. Parent ZSM-5 and its mesoporous derivatives obtained by desilication were used to prepare (Fe species)@(zeolite matrix) composites. The synthesis was carried out by co-precipitating Fe²⁺/Fe³⁺ ions onto both parent and desilicated ZSM-5 matrices under oxygen-free conditions. Comprehensive characterization by X-ray diffraction, scanning electron microscopy, N₂ adsorption, vibrating-sample magnetometry, ⁵⁷Fe Mössbauer spectroscopy, and diffuse reflectance UV–Vis spectroscopy revealed that the degree of introduced mesoporosity dramatically influences the size, dispersion, phase composition, and oxidation state of the iron-containing nanospecies. On purely microporous ZSM-5, relatively large (~15 nm) partially oxidized magnetite nanoparticles are formed predominantly on the external surface, exhibiting superparamagnetism at room temperature (Mₛ = 11 emu/g) and a band gap of 2.12 eV. Increasing mesoporosity leads to progressively smaller and more highly dispersed iron(III) oxo/hydroxo clusters with significantly lower blocking temperatures and reduced magnetization (down to 0.7 emu/g for Fe@ZSM-5_0.4). All composites display strong visible-light absorption confirming their potential as magnetically separable visible-light-driven photocatalysts for environmental remediation. Full article

Magnetite (Fe₃O₄) nanoparticles are biocompatible, non-toxic, and easily functionalized. Coating them with mesoporous silica (mSiO₂) offers high surface area, pore volume, and tunable surface chemistry for drug loading. In this study, Fe₃O₄ magnetic nanoparticles were synthesized and coated with mSiO₂ shells enriched with calcium ions (Ca²⁺), aiming to enhance bioactivity for bone regeneration and tissue engineering. Different synthesis routes were tested to optimize shell formation Their characterization confirmed the presence of a crystalline Fe₃O₄ core with partial conversion to maghemite (Fe₂O₃) post-coating. The silica shell was mostly amorphous and the optimized samples exhibited mesoporous structure (type IVb). Calcium incorporation slightly altered the magnetic properties without significantly affecting core crystallinity or particle size (11.68–13.56 nm). VSM analysis displayed symmetric hysteresis loops and decreased saturation magnetization after coating and Ca²⁺ addition. TEM showed spherical morphology with some agglomeration. MTT assays confirmed overall non-toxicity, except for mild cytotoxicity at high concentrations in the Ca²⁺-enriched sample synthesized by a modified Stöber method. Their capacity to induce human periodontal ligament cell osteogenic differentiation, further supports the potential of Fe₃O₄/mSiO₂/Ca²⁺ core–shell nanoparticles as promising candidates for bone-related biomedical applications due to their favorable magnetic, structural, and biological properties. Full article

Cancer remains a severe global health threat, with traditional therapies often plagued by limited efficacy and significant side effects. The emergence of nanotechnology, particularly metal-doped nanomaterials, offers a promising avenue for integrating diagnostic and therapeutic functions into a single platform, enabling a theranostic approach to oncology. This article explores the design and application of various metal-doped nanosystems, including gadolinium-doped selenium molybdenum nanosheets for magnetic resonance/photoacoustic dual-mode imaging and photothermal therapy, and metal-doped hollow mesoporous silica nanoparticles that leverage the tumor’s acidic microenvironment to release ions for catalytic generation of reactive oxygen species. Despite their promise, the limited enzyme-like activity of some nanozymes, insufficient endogenous hydrogen peroxide in tumors, and the tumor microenvironment’s defensive mechanisms, such as high glutathione levels, can restrict therapeutic efficacy. Looking forward, the outlook for the field is contingent upon advancing material engineering strategies. Future research should prioritize the development of intelligent, multifunctional nanoplatforms that can dynamically respond to and remodel the tumor microenvironment. Innovations in surface modification for enhanced targeting, alongside rigorous preclinical studies focused on safety and standardized manufacturing, are crucial for bridging the gap between laboratory research and clinical application, ultimately paving the way for personalized cancer medicine. Full article

Easy and rapid preparations of magnetic Co- and Pd-containing mesoporous carbons (IM1, IM2 and DM) from green phenolic resins, amphiphilic templates and metallic salts via two synthetic routes are reported. Catalysts IM1 and IM2 are prepared via an indirect method involving two steps, i.e., the preparation of Co-containing mesoporous carbons with different Co contents (2.5 and 12.5%) and the further introduction of Pd (2.3%) via impregnation using a solution of a Pd salt and a process of thermal reduction. The mesoporous carbon obtained contains two distinct crystalline metallic phases, i.e., Co particles of 5.0 nm (IM1) and Pd nanoparticles of ~1.3 nm (IM1), while the increase in Co content triggers higher Co particle sizes of 23 nm and Pd particle sizes of 1.3 and 6.8 nm (IM2). Differently, the catalyst DM is prepared via direct synthesis, in one step, including all precursors and both metal salts. This results in Pd₅₀-Co₅₀ nanoalloys of 6.5 nm uniformly dispersed in the carbon matrix. The reactivity and reusability of catalysts IM1, IM2 and DM were then ascertained in organic synthesis for hydrogenations of nitroarenes and enones. It turned out that no reactions were observed in the presence of the catalyst DM due to the presence of Co in Pd₅₀-Co₅₀, which deactivates the catalytic activity of Pd. Gratifyingly, catalysts IM1 and IM2 were very efficient for mild hydrogenations of both nitroarenes and enones using only 5 mequiv. of supported Pd in EtOH at room temperature. The smaller Pd particle sizes (1.3 nm) and the high surface-to-volume area are probably responsible for the high reactivity observed. Catalysts IM1 and IM2 can be recovered by application of an external magnetic field. However, a more efficient magnetic recovery of catalyst IM2 compared to IM1 was observed due to its higher Co content. Catalyst IM2 can be successfully reused at least seven times without a loss of efficiency. Finally, almost-Pd-free products can be obtained directly after reaction without any purification step, since the Pd leaching is very low (<0.1% of the initial amount), thus decreasing waste and increasing the reaction’s efficiency. Full article

A method combining magnetic solid-phase extraction (MSPE) with ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of diazepam residues in aquatic products. A novel magnetic nanoparticle material, Fe₃O₄@SiO₂@DVB-NVP, was synthesized and applied as an adsorbent for sample cleanup. The sample preparation procedure involved extraction with 1% ammonia–acetonitrile, followed by purification using the MSPE technique to efficiently remove matrix interferents. Chromatographic separation was achieved on an ACQUITY UPLC BEH C₁₈ column with a gradient elution program using a mobile phase composed of 0.1% formic acid–2 mM ammonium acetate solution and methanol. Detection was performed under multiple-reaction monitoring (MRM) mode with positive electrospray ionization (ESI⁺). Quantification was carried out using the external standard method. The synthesized magnetic material was characterized using SEM, TEM, FTIR, XRD, BET, and VSM, confirming its mesoporous structure, strong adsorption capacity, and excellent magnetic responsiveness. The method demonstrated good linearity over the concentration range of 0.25–50 μg/L (r² = 0.997). The limits of detection and quantification were 0.20 μg/kg and 0.50 μg/kg, respectively. Average recoveries from spiked blank matrices at three levels (0.5, 2.5, and 5.0 μg/kg) ranged from 89.3% to 119.7%, with relative standard deviations (RSDs) between 0.8% and 10.2%. The proposed method is highly selective, exhibits minimal matrix interference, and provides reliable quantitative performance, making it suitable for the qualitative and quantitative analysis of diazepam residues in aquatic products. Full article

Among the many nanomaterials studied for biomedical uses, silica and gold nanoparticles have gained significant attention because of their unique physical and chemical properties and their compatibility with living tissues. Mesoporous silica nanoparticles (MSNs) have great stability and a large surface area, while gold nanoparticles (AuNPs) display remarkable optical features. Both types of nanoparticles have been widely researched for their individual roles in drug delivery, imaging, biosensing, and therapy. When combined with gadolinium (Gd), a common contrast agent, these nanostructures provide improved imaging due to gadolinium’s strong paramagnetic properties. This study focuses on incorporating gold nanoparticles and gadolinium into a silica matrix to develop a theranostic system. Various analytical techniques were used to characterize the nanocomposites, including infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), nitrogen adsorption, scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray fluorescence (XRF), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and neutron activation analysis (NAA). Techniques like XRF mapping, XANES, nitrogen adsorption, SEM, and VSM were crucial in confirming the presence of gadolinium and gold within the silica network. VSM and EPR analyses confirmed the attenuation of the saturation magnetization for all nanocomposites. This validates their potential for biomedical applications in diagnostics. Moreover, activating gold nanoparticles in a nuclear reactor generated a promising radioisotope for cancer treatment. These results indicate the potential of using a theranostic nanoplatform that employs mesoporous silica as a carrier, gold nanoparticles for radioisotopes, and gadolinium for imaging purposes. Full article

Lanthanide rare earth elements possess significant promise for material applications owing to their distinctive optical and magnetic characteristics, as well as their versatile coordination capabilities. This study introduced a lanthanide-functionalized magnetic nanocellulose composite (NNC@Fe₃O₄@La(OH)₃) for effective phosphorus/nitrogen (P/N) ligand separation. The hybrid material employs the adaptable coordination geometry and strong affinity for oxygen of La³⁺ ions to show enhanced DNA-binding capacity via multi-site coordination with phosphate backbones and bases. This study utilized cellulose as a carrier, which was modified through carboxylation and amination processes employing deep eutectic solvents (DES) and polyethyleneimine. Magnetic nanoparticles and La(OH)₃ were subsequently incorporated into the cellulose via in situ growth. NNC@Fe₃O₄@La(OH)₃ showed a specific surface area of 36.2 m²·g⁻¹ and a magnetic saturation intensity of 37 emu/g, facilitating the formation of ligands with accessible La³⁺ active sites, hence creating mesoporous interfaces that allow for fast separation. NNC@Fe₃O₄@La(OH)₃ showed a significant affinity for DNA, with adsorption capacities reaching 243 mg/g, mostly due to the multistage coordination binding of La³⁺ to the phosphate groups and bases of DNA. Simultaneously, kinetic experiments indicated that the binding process adhered to a pseudo-secondary kinetic model, predominantly dependent on chemisorption. This study developed a unique rare-earth coordination-driven functional hybrid material, which is highly significant for constructing selective separation platforms for P/N-containing ligands. Full article

A sensitive method was developed for detecting diazepam residues in aquatic products using magnetic dispersive solid-phase extraction (MDSPE) coupled with ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Samples extracted with 1% ammonia–acetonitrile were purified using synthesized Fe₃O₄@SiO₂-PSA nanoparticles via MDSPE before UPLC-MS/MS analysis. Separation was performed on a C₁₈ column with gradient elution using 0.1% formic acid–2 mM ammonium acetate/methanol. Detection employed positive electrospray ionization (ESI⁺) in multiple reaction monitoring (MRM) mode. Characterization confirmed Fe₃O₄@SiO₂-PSA’s mesoporous structure with excellent adsorption capacity and magnetic properties. The method showed good linearity (0.1–10 μg/L, r > 0.99) with an LOD and LOQ of 0.20 μg/kg and 0.50 μg/kg, respectively. Recoveries at 0.5–15.0 µg/kg spiking levels were 74.9–109% (RSDs 1.24–11.6%). This approach provides rapid, accurate, and high-precision analysis of diazepam in aquatic products, meeting regulatory requirements. Full article