Search Results (195)

Background: Platelet-rich fibrin (PRF) is an autologous platelet concentrate (APC) produced through blood centrifugation. Despite the development of various centrifugation systems, protocol variability continues to pose challenges in selecting the optimal method. This study investigated the effects of three different centrifuges and collection tubes on the fibrin characteristics and growth factor release in leukocyte- and platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin plus (A-PRF+). Methods: Blood samples from six healthy female volunteers were processed using three centrifuges (Duo, IntraSpin, and LMC-3000) and three collection tubes (Pyrex, A-P, and silica-coated plastic) under high- (~700× g for 12 min) and low-speed (~200× g for 8 min) protocols. Fibrin clot weight and length were assessed. Growth factor release of platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor (VEGF) was quantified using ELISA. Fibrin architecture was examined via scanning electron microscopy (SEM). Results: High-speed protocols tended to produce larger clots, whereas low-speed protocols generated smaller but more biologically active matrices. The IntraSpin and Duo centrifuges yielded greater clot dimensions and higher growth factor release than the LMC-3000. While tube type had no significant effect on growth factor levels, silica-coated tubes tended to produce the largest clots. The Pyrex tubes demonstrated comparable or superior growth factor release. Conclusions: PRF quality is influenced by centrifuge design, g-force, and tube material. Low-speed protocols with certified centrifuges are recommended, and FDA-approved glass tubes may provide a reliable alternative to reduce silica-related risks. Standardization and appropriate material selection are essential for consistent, safe, and effective regenerative outcomes. Full article

Waste materials have emerged as attractive low-cost feedstocks for adsorbent development in environmental remediation and materials engineering. Organic wastes are particularly rich in cellulose, hemicellulose, lignin, and pectin, which provide reactive oxygenated groups such as hydroxyls and carboxyls. While inorganic wastes offer stability, lower water retention makes them promising candidates. This study explores the functionalization of waste-derived organic and inorganic matrices using two amine-based agents: 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI). The materials were categorized as organic (orange peel, corn cob) or inorganic (silica gel, eggshell) and subjected to a pretreatment process involving drying, grinding, and sieving; inorganic substrates additionally underwent acid activation with citric acid. Surface modification was carried out in ethanolic (APTMS) or aqueous (PEI) media. To assess their suitability and processability as particulate sorbents, drying kinetics, physicochemical properties (FTIR, ζ-potential, pH, conductivity, Boehm titration), and flow characteristics (Carr and Hausner indices) were evaluated. The findings enable a comparative analysis of the functionalization efficiency and elucidate the relationship between substrate type (organic vs. inorganic) and its performance as a modified adsorbent. This approach advances the development of novel sorbent matrices for greenhouse gas mitigation while reinforcing circular economy principles through the valorization of low-cost, readily available waste materials. Full article

Alginate hydrogels are promising tissue engineering biomaterials due to their biocompatibility and structural similarity to the extracellular matrix, but their poor mechanical strength, rapid degradation, and lack of bioactivity limit applications. To address this, a novel oxidized alginate/polyacrylamide/silica nanoparticle–gelatin (OA/PAAm/SiO₂-GT) composite hydrogel was developed using an interpenetrating polymer network (IPN) strategy, reinforced with silica nanoparticles and coated with gelatin. The influence of SiO₂ content on the microstructure, mechanical properties, swelling behavior, biodegradability, biomineralization, and cytocompatibility of the composite hydrogel was systematically investigated. Experimental results revealed that SiO₂ nanoparticles interacted with the polymer matrix within the composite hydrogel. With increasing content of SiO₂, the porosity of the OA/PAAm/SiO₂-GT composite hydrogel gradually decreased, while the mechanical properties exhibited a trend of initial enhancement followed by reduction, with maximum compressive strength at a SiO₂ content of 1.0% (w/v). Moreover, the incorporation of SiO₂ nanoparticles effectively modulated the swelling behavior, biodegradability, and biomineralization capacity of the composite hydrogel under in vitro conditions. Meanwhile, the OA/PAAm/SiO₂-GT composite hydrogel supported favorable cell adhesion and proliferation, optimal at a SiO₂ content of 0.5% (w/v). Furthermore, with increasing concentration of SiO₂ nanoparticles, the intracellular alkaline phosphatase (ALP) activity progressively increased, suggesting a promotive effect of SiO₂ nanoparticles on the osteogenic differentiation of MG63 cells. Therefore, the incorporation of SiO₂ nanoparticles into the OA/PAAm IPN matrices provides an effective means to tailor its biological properties, rendering it great potential for biomedical applications such as tissue engineering. Full article

The paper reports on obtaining visually appealing images from opal matrices to artificial samples comprising regular packing of monodisperse silica globules. We show the images of iridescence, photoluminescence, and both of them simultaneously, exciting upconversion luminescence of Er³⁺ ions from BaTiO₃ xerogel/opal matrix. Opal matrix with BaTiO₃ xerogel doped with Er³⁺ and Yb³⁺ ions demonstrates upconversion luminescence under excitation with the wavelength 980 nm of the laser with the main bands ranging from 500 to 570 nm and 640–700 nm, corresponding to the transitions from the excited states ²H_11/2, ⁴S_3/2, ⁴F_9/2, ⁴I_9/2 to the ground state ⁴I_15/2 of trivalent Er ions. In our view, the synthesis of opal matrices along with the generation of luminescent xerogels doped, for example, with trivalent lanthanides, is a promising approach for obtaining colorful images, always very individual and often very attractive, bringing joy and pleasure at concerts and other show business events. Full article

Elderberry (Sambucus nigra L.) is recognized as a rich source of anthocyanins and other bioactives with antioxidant and antidiabetic potential, and is increasingly explored as a functional ingredient in nutraceuticals. However, cultivar-dependent variability can strongly influence chemical composition and bioactivity, underscoring the need for careful selection of plant material prior to formulation. In the present study, twelve genotypes of elderberry were compared in terms of total polyphenols, antioxidant activity, and antiglycation potential. Based on the overall profile, ‘Samyl 1’ was advanced to formulation trials. Spray-dried carrier systems were produced using galactooligosaccharides (GOS) or chitooligosaccharides (COS), with or without colloidal silica. GOS-based powders retained anthocyanins at levels approaching theoretical values and exhibited superior thermal stability, as evidenced by differential scanning calorimetry, thermogravimetric analysis, and degradation-kinetic modeling, whereas COS matrices provided less effective stabilization. Incorporation of silica significantly enhanced technological properties, improving recovery, reducing agglomeration, and increasing flowability, without compromising anthocyanin content. All powders displayed low moisture (2.5–7.1%), favorable morphology, and preserved functional activity, aligning with stability requirements for shelf-stable plant extracts. Overall, the study demonstrates that strategic cultivar selection combined with GOS–silica carrier systems enables the production of stable elderberry powders that maintain high anthocyanin content and bioactivity. Such multifunctional ingredients couple prebiotic functionality with efficient delivery of polyphenols, highlighting their potential in nutraceutical and pharmaceutical formulations. Full article

Two nitrogen-modified mesoporous MCM-41-type silicas were synthesized by the sol–gel route and post-grafting surface modification procedure, obtaining an aminopropyl-modified MCM-41 (denoted MCM-41-N) and an aminoethyl-aminopropyl-modified MCM-41 (denoted MCM-41-NN). Hexavalent chromium removal from acidified water by adsorption and reduction to Cr(III) on the solid mesophases was analyzed. The modified silicas were characterized by powder X-ray diffraction (XRD), Fourier transformed infrared spectra (FT-IR), nitrogen adsorption–desorption measurements at −196 °C, X-ray photoelectron spectroscopy (XPS), ²⁹Si solid state Nuclear Magnetic Resonance (²⁹Si-RMN), and thermogravimetric analysis (TGA). Both samples exhibited very high capacities for decreasing Cr(VI) concentrations in water, according to the Langmuir isotherm model: 129.9 mg·g⁻¹ for MCM-41-N and 133.3 mg·g⁻¹ for MCM-41-NN. The chromium speciation in the supernatant after 24 h indicates that MCM-41-N had a higher capacity to reduce Cr(VI) to the less toxic Cr(III) species than MCM-41-NN: 92.9% vs. 72.5% when the initial Cr(VI) concentration was 10 mg·g⁻¹. These differences were related to the different capacity of nitrogen atoms in MCM-41-N and MCM-41-NN to interact with the surrounding surface silanols which are required for the chemical reduction in the hexavalent species to take place, as evidenced by FT-IR and XPS analysis. Also, the Cr(III)/Cr(VI) atomic ratios on the solid’s surfaces were higher for MCM-41-N. These results highlight the characteristics that nitrogen atoms incorporated into silica matrices must possess in order to maximize the transformation of Cr(VI) into the trivalent species, thereby reducing the generation of toxic waste harmful to living organisms. Full article

Colloidal quantum dots (QDs) are semiconductor crystals a few nanometers in size. Due to their vibrant colors and unique photoluminescence (PL), QDs are widely utilized in displays, where barrier films provide essential shielding. However, one of the primary challenges of QD applications remains achieving sufficient robustness while keeping costs low. Over the past two decades, significant progress has been made in the encapsulation of QDs within silica matrices, aiming to preserve their original PL properties. Research efforts have evolved from bulk forms to thin films. Silica nanoparticles containing multiple embedded QDs have emerged as particularly promising candidates for practical applications. This review highlights recent advancements in silica-based QD encapsulation, incorporating findings from both the authors’ investigations and those of other research groups within the field. Silica glass possesses inherent shielding capabilities, but silane coupling agents such as (3-aminopropyl)trimethoxysilane and (3-mercaptopropyl)trimethoxysilane tend to negatively impact this functionality when they are used alone, partly because of the limited formation of a well-developed glass network structure. However, when judiciously controlled, they can serve as mediators between the QD surface and the surrounding pure silica glass matrix, helping to preserve PL properties and control the morphology of silica particles. This review discusses the potential for achieving exceptional shielding properties through sol–gel glass fabrication at low temperatures, utilizing both tetraethoxysilane and other silane coupling agents. Full article

The application of glass fiber reinforced polymer (GFRP) bars offers a promising solution for enhancing the durability of reinforced concrete structures, potentially reducing maintenance costs and associated socioeconomic impacts. However, concerns persist regarding the durability of GFRP bars in the highly alkaline environment of concrete, which can lead to physical, chemical, and mechanical degradation. This study evaluates the durability of GFRP bars composed of isophthalic polyester, vinyl ester, and epoxy matrices (6.0 mm diameter) under accelerated aging conditions. The bars were exposed to non-carbonated concrete (with and without silica fume) and carbonated concrete at temperatures of 23 °C, 40 °C, and 60 °C for durations of 500, 1000, and 3000 h. Interlaminar shear strength (ISS) was measured before and after aging. SEM and FTIR analyses confirmed degradation in the polymer matrix and fiber–matrix interface. Results indicated that silica fume significantly mitigated alkalinity effects, limiting ISS loss to 11.3%. Similarly, carbonation reduced the concrete’s pH, thereby decreasing ISS degradation to 10.7% after 3000 h. Among the tested materials, GFRP bars with vinyl ester matrix exhibited superior durability, followed by those with epoxy and polyester matrices. These findings emphasize the critical role of matrix selection and concrete mix design in improving GFRP durability. Full article

Cervical cancer represents a significant global health challenge. Photodynamic therapy (PDT) appears to be a promising, minimally invasive alternative to standard treatments. However, the clinical efficacy of PDT is sometimes limited by the low solubility and aggregation of photosensitizers, their non-selective distribution in the body, hypoxia in the tumor microenvironment, and limited light penetration. Recent advances in nanoparticle and nanocomposite platforms have addressed these challenges by integrating multiple functional components into a single delivery system. By encapsulating or conjugating photosensitizers in biodegradable matrices, such as mesoporous silica, organometallic structures and core–shell construct nanocarriers increase stability in water and extend circulation time, enabling both passive and active targeting through ligand decoration. Up-conversion and dual-wavelength responsive cores facilitate deep light conversion in tissues, while simultaneous delivery of hypoxia-modulating agents alleviates oxygen deprivation to sustain reactive oxygen species generation. Controllable “motor-cargo” constructs and surface modifications improve intratumoral diffusion, while aggregation-induced emission dyes and plasmonic elements support real-time imaging and quantitative monitoring of therapeutic response. Together, these multifunctional nanosystems have demonstrated potent cytotoxicity in vitro and significant tumor suppression in vivo in mouse models of cervical cancer. Combining targeted delivery, controlled release, hypoxia mitigation, and image guidance, engineered nanoparticles provide a versatile and powerful platform to overcome the current limitations of PDT and pave the way toward more effective, patient-specific treatments for cervical malignancies. Our review of the literature summarizes studies on nanoparticles and nanocomposites used in PDT monotherapy for cervical cancer, published between 2023 and July 2025. Full article

Silica-modified electrodes possess physicochemical properties that make them valuable in electrochemical sensing and energy-related applications. Although intrinsically insulating, silica thin films can selectively interact with redox species, producing sieving effects that enhance electrochemical responses. We synthesized Class I hybrid silica matrices incorporating either negatively charged poly(4-styrene sulfonic acid) or positively charged poly(diallyl dimethylammonium chloride). These hybrid films were deposited onto ITO electrodes and evaluated via cyclic voltammetry in aqueous ferrocenium solutions. The polyelectrolyte charge played a key role in the electroassisted incorporation of ferrocene: silica-PSS films promoted accumulation, while silica-PDADMAC films hindered it due to electrostatic repulsion. In situ UV-vis spectroscopy confirmed that only a fraction of the embedded ferrocene was electroactive. Nevertheless, this fraction enabled effective mediated detection of cytochrome c in solution. These findings highlight the crucial role of ionic interactions and hybrid composition in electron transfer to redox proteins, providing valuable insights for the development of advanced bioelectronic sensors. Full article

A modular strategy for the molecular design of silicone-based antifoaming agents was developed by precisely controlling the architecture of poly (methylhydrosiloxane) (PMHS). Sixteen PMHS variants were synthesized by systematically varying the siloxane chain length (L1–L4), backbone composition (D₃T₁ vs. D₃₀T₁), and terminal group chemistry (H- vs. M-type). These structural modifications resulted in a broad range of Si-H functionalities, which were quantitatively analyzed and correlated with defoaming performance. The PMHS matrices were integrated with high-viscosity PDMS, a nonionic surfactant, and covalently grafted fumed silica—which was chemically matched to each PMHS backbone—to construct formulation-specific defoaming systems with enhanced interfacial compatibility and colloidal stability. Comprehensive physicochemical characterization via FT-IR, ¹H NMR, GPC, TGA, and surface tension analysis revealed a nonmonotonic relationship between Si-H content and defoaming efficiency. Formulations containing 0.1–0.3 wt% Si-H achieved peak performance, with suppression efficiencies up to 96.6% and surface tensions as low as 18.9 mN/m. Deviations from this optimal range impaired performance due to interfacial over-reactivity or reduced mobility. Furthermore, thermal stability and molecular weight distribution were found to be governed by repeat unit architecture and terminal group selection. Compared with conventional EO/PO-modified commercial defoamers, the PMHS-based systems exhibited markedly improved suppression durability and formulation stability in high-viscosity environments. These results establish a predictive structure–property framework for tailoring antifoaming agents and highlight PMHS-based formulations as advanced foam suppressors with improved functionality. This study provides actionable design criteria for high-performance silicone materials with strong potential for application in thermally and mechanically demanding environments such as coating, bioprocessing, and polymer manufacturing. Full article

Background/Objectives: Mesoporous silica materials, particularly KIT-6, offer promising features, such as large surface area, tunable pore structures, and biocompatibility, making them ideal candidates for advanced drug delivery systems. The aims of this study were to develop and evaluate an innovative modified-release platform for metformin hydrochloride (MTF), using KIT-6 mesoporous silica as a matrix, to enhance oral antidiabetic therapy. Methods: KIT-6 was synthesized using an ultrasound-assisted sol-gel method and subsequently loaded with MTF via adsorption from alkaline aqueous solutions at two concentrations (1 and 3 mg/mL). The structural and morphological characteristics of the matrices—before and after drug loading—were assessed using SEM-EDX, TEM, and nitrogen adsorption–desorption isotherms (the BET method). In vitro drug release profiles were recorded in simulated gastric and intestinal fluids over 12 h. Kinetic modeling was performed using seven classical models, and a multifractal theoretical framework was used to further interpret the complex release behavior. Results: The loading efficiency increased with increasing drug concentration but nonlinearly, reaching 56.43 mg/g for 1 mg/mL and 131.69 mg/g for 3 mg/mL. BET analysis confirmed significant reductions in the surface area and pore volume upon MTF incorporation. In vitro dissolution showed a biphasic release: a fast initial phase in an acidic medium followed by sustained release at a neutral pH. The Korsmeyer–Peppas and Weibull models best described the release profiles, indicating a predominantly diffusion-controlled mechanism. The multifractal model supported the experimental findings, capturing nonlinear dynamics, memory effects, and soliton-like transport behavior across resolution scales. Conclusions: The study confirms the potential of KIT-6 as a reliable and efficient carrier for the modified oral delivery of metformin. The combination of experimental and multifractal modeling provides a deeper understanding of drug release mechanisms in mesoporous systems and offers a predictive tool for future drug delivery design. This integrated approach can be extended to other active pharmaceutical ingredients with complex release requirements. Full article

In this study, an innovative dental functionalized magnetic nanomaterial was developed by incorporating hydrophilic magnetic clusters as an alternative to conventional isolated magnetic nanoparticles, introducing a novel structural and functional concept in dental applications. The ~100 nm magnetic clusters—composed of densely packed 7 nm Fe₃O₄ nanoparticles—were sequentially coated with a silica (SiO₂) layer (3–5 nm) to improve chemical and mechanical stability, followed by an outer calcium hydroxide [Ca(OH)₂] layer to enhance bioactivity and optical integration. This bilayer architecture enables magnetic field-assisted positioning and improved dispersion within dental resin matrices. Silver nanoparticles were incorporated to enhance antimicrobial activity and reduce biofilm formation. The synthesis process was environmentally friendly and scalable. Comprehensive physicochemical characterization confirmed the material’s functional performance. Saturation magnetization decreased progressively with surface functionalization, from 62 to 14 emu/g, while the zeta potential became increasingly negative (from −2.42 to −22.5 mV), supporting its ability to promote apatite nucleation. The thermal conductivity (0.527 W/m·K) closely matched that of human dentin (0.44 W/m·K), and the colorimetric analysis showed improved brightness (ΔL = 5.3) and good color compatibility (ΔE = 11.76). These results indicate that the functionalized magnetic nanomaterial meets essential criteria for restorative use and holds strong potential for future clinical applications. Full article

To address the challenges of nonspecific adsorption interference and low mass transfer efficiency encountered by electrochemiluminescence (ECL) sensors in complex biological matrices, this study developed a Mn@CeO₂ nanozyme-based sensing interface. The Mn-doped CeO₂ enhanced electron transfer efficiency, increased oxygen vacancy concentration, and stabilized the Mn-O-Ce structure, collectively enabling highly efficient peroxidase (POD)-like activity. The design significantly improved ECL reaction efficiency, which simultaneously conferred synergistic antifouling and mass transport enhancing properties. The mesoporous silica nanoparticle on the sensing interface accelerated mass transfer processes, thereby overcoming the limitations of traditional diffusion-controlled kinetics. The Mn@CeO₂ nanozyme and mesoporous silica nanoparticle synergistically improved electron transfer and reactant enrichment, thereby significantly enhancing the signal response. Concurrently, a biomimetic anti-fouling coating was introduced at the interface to effectively suppress nonspecific adsorption of interferents. The constructed nanozyme-enhanced ECL sensing platform was demonstrated through the detection of dopamine (DA) as a model neurotransmitter, exhibiting favorable detection performance while maintaining high-accuracy detection in complex biological samples. This strategy offers a novel approach to developing highly sensitive and interference-resistant ECL sensors, with promising applications in disease biomarker monitoring and live physiological sample analysis. Full article

To enhance the signal intensity of kynurenines, which are present at trace concentrations in biological fluids, a novel analytical approach was developed, combining pressure-assisted electrokinetic injection (PAEKI) with a mixed micelle system based on sodium dodecyl sulfate (SDS) and Brij-35. The method was applied to key compounds of the kynurenine pathway, including L-tryptophan, kynurenine, 3-hydroxykynurenine, and kynurenic acid, as well as to the aromatic amino acids (AAs) L-tyrosine and L-phenylalanine. PAEKI was performed by electrokinetic injection for 2 min at −6.5 kV (reversed polarity) and 0.5 psi (3.45 kPa) using a fused silica capillary (50 cm in length, 50 µm inner diameter). The background electrolyte (BGE) consisted of 20 mM Na₂B₄O₇ (pH 9.2), 2 mM Brij-35, 20 mM SDS, and 20% (v/v) methanol (MeOH). The limit of detection (LOD) using a diode array detector (DAD) was 1.2 ng/mL for kynurenine and ranged from 1.5 to 3.0 ng/mL for the other analytes. The application of PAEKI in conjunction with micellar electrokinetic capillary chromatography (MEKC) and solid-phase extraction (SPE) of artificial urine samples resulted in a 146-fold increase in signal intensity for kynurenines compared to that observed using the hydrodynamic injection (HDI) mode. The developed method demonstrates strong potential for determining kynurenine pathway metabolites in complex biological matrices. Full article