Search Results (132)

Bioactive agents can stimulate osteogenesis, angiogenesis, and cell proliferation; therefore, their application in bone regeneration offers significant therapeutic potential. The aim of this systematic review was to evaluate strategies for applying chitosan-based scaffolds with growth factors in bone regeneration. A structured literature search was conducted in July 2025 across the PubMed, Scopus, and Web of Science databases. Search terms included combinations of (chitosan scaffold) AND (growth factor OR BMP-2 OR VEGF OR FGF OR TGF-beta OR periostin OR PDGF OR IGF-1 OR EGF OR ANG-1 OR ANG-2 OR GDF-5 OR SDF-1 OR osteopontin). The study selection process followed PRISMA 2020 guidelines and the PICO framework. Out of 367 records, 226 were screened, and 17 studies met the eligibility criteria for qualitative analysis. BMP-2 was the most frequently investigated growth factor, studied in both in vitro and in vivo models, with rats and rabbits as the most common animal models. Scaffold compositions varied, incorporating hydroxyapatite, heparin, polyethylene glycol diacrylate, octacalcium phosphate-mineralized graphene, silk fibroin, and aloe vera. Growth factors were introduced using diverse methods, including microspheres, chemical grafting, covalent coupling, protein carriers, and nanohydroxyapatite mesopores. Most studies reported enhanced bone regeneration, although differences in models, scaffold composition, and delivery methods preclude definitive conclusions. The addition of growth factors generally improved osteoblast proliferation, angiogenesis, bone density, and expression of osteogenic markers (RunX2, COL1, OPN, OCN). Combining two bioactive agents further amplified osteoinduction and vascularization. Sustained-release systems, particularly those using heparin or hydroxyapatite, prolonged biological activity and improved regenerative outcomes. In conclusion, functionalization of chitosan-based scaffolds with growth factors shows promising potential for bone regeneration. Controlled-release systems and combinations of different bioactive molecules may offer synergistic effects on osteogenesis and angiogenesis. Further research should focus on optimizing scaffold compositions and delivery methods to tailor bioactive agent release for specific clinical applications. Full article

The controlled incorporation of halogens into carbon materials remains a challenge, particularly under mild and scalable conditions. In this work, we investigate the fixation of iodine on high-surface-area graphite (HSAG-100) using green solvents and moderate temperatures. Commercial HSAG was treated with iodine in aqueous and in organic media, with and without promoters, and characterized by XPS, LEIS, N₂ physisorption, TGA/TPD, and XRD. The results reveal that iodine contents up to ~0.6 at% can be achieved, with incorporation strongly influenced by solvent and reaction time. XPS and LEIS confirmed the presence of C–I bonds, while BET analysis showed only moderate decreases in surface area and unchanged mesopore size distribution. Thermogravimetric and TPD analyses demonstrated the high thermal stability of C–I species, and XRD patterns ruled out intercalation between graphene layers. Collectively, these findings demonstrate that iodine can be covalently anchored to HSAG under mild conditions, preserving the graphitic structure and generating stable edge functionalities, thus opening a route for the design of halogen-doped carbons for catalytic and electrochemical applications. Full article

This work evaluates the CO₂-adsorption relevance and cycling stability of graphene oxide–silica (GO-SiO₂) and reduced graphene oxide–silica (rGO-SiO₂) gels after amine functionalization, demonstrating high-capacity retention under repeated adsorption–desorption cycles: rGO-SiO₂-APTMS retains ≈96.3% of its initial uptake after 50 cycles, while GO-SiO₂-APTMS retains ≈90.0%. The use of surfactants to control the organization of inorganic and organic molecules has enabled the development of ordered mesostructures, such as mesoporous silica and organic/inorganic nanocomposites. Owing to the outstanding properties of graphene and its derivatives, synthesizing mesostructures intercalated between graphene sheets offers nanocomposites with novel morphologies and enhanced functionalities. In this study, GO-SiO₂ and rGO-SiO₂ gels were synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), mass spectrometry (MS), N₂ adsorption–desorption isotherms, and transmission electron microscopy (TEM). The resulting materials exhibit a laminar architecture, with mesoporous silica domains grown between graphene-based layers; the silica contents are 83.6% and 87.6%, and the specific surface areas reach 446 and 710 m²·g⁻¹, respectively. The laminar architecture is retained regardless of the surfactant-removal route; however, in GO-SiO₂ obtained by solvent extraction, a fraction of the surfactant remains partially trapped. Together with their high surface area, hierarchical porosity, and amenability to surface functionalization, these features establish amine-grafted graphene–silica gels, particularly rGO-SiO₂-APTMS, as promising CO₂-capture adsorbents. Full article

This study reported covalent organic frameworks (COFs) and their hybrid composites with two-dimensional materials, graphene oxide (GO), graphitic carbon nitride (g-C₃N₄), and boron nitride (BN), to examine their structural, textural, and gas adsorption properties. Material characterization confirmed the crystallinity of COF-1 and the preservation of framework integrity after integrating the 2D nanomaterials. FT-IR spectra exhibited pronounced vibrational fingerprints of imine linkages and validated the functional groups from the COF and the integrated nanomaterials. TEM images revealed the integration of the two components, porous, layered structures with indications of interfacial interactions between COF and 2D nanosheets. Nitrogen adsorption–desorption isotherms revealed the microporous characteristics of the COFs, with hysteresis loops evident, indicating the development of supplementary mesopores at the interface between COF-1 and the 2D materials. The BET surface area of pristine COF-1 was maximal at 437 m²/g, accompanied by significant micropore and Langmuir surface areas of 348 and 1290 m²/g, respectively, offering enhanced average pore widths and hierarchical porous strcuture. CO₂ adsorption tests were investigated showing maximum adsorption capacitiy of 1.47 mmol/g, for COF-1, closely followed by COF@BN at 1.40 mmol/g, underscoring the preserved sorption capabilities of these materials. These findings demonstrate the promise of designed COF-based hybrids for gas capture, separation, and environmental remediation applications. Full article

Protein phosphorylation is one of the most common and important post-translational modifications (PTMs) and is highly involved in various biological processes. Ideal adsorbents with high sensitivity and specificity toward phosphopeptides with large coverage are therefore essential for enrichment and mass spectroscopy-based phosphoproteomics analysis. In this study, a newly designed IMAC adsorbent composite was constructed on the graphene matrix coated with mesoporous silica. The outer functional 3D-network layer was prepared by free radical polymerization of the phosphonate-functionalized vinyl imidazolium salt monomer and subsequent metal immobilization. Due to its unique structural feature and high content of Ti⁴⁺ ions, the resulting phosphonate-immobilized adsorbent composite G@mSiO₂@PPFIL-Ti⁴⁺ exhibits excellent performance in phosphopeptide enrichment with a low detection limit (0.1 fmol, tryptic β-casein digest) and superior selectivity (molar ratio of 1:15,000, digest mixture of β-casein and bovine serum albumin). G@mSiO₂@PPFIL-Ti⁴⁺ displays high tolerance to loading and elution conditions and thus can be reused without a marked decrease in enrichment efficacy. The captured phosphopeptides can be released globally, and mono-/multi-phosphopeptides can be isolated stepwise by gradient elution. When applying this material to enrich phosphopeptides from human lung cell lysates, a total of 3268 unique phosphopeptides were identified, corresponding to 1293 phosphoproteins. Furthermore, 2698 phosphorylated peptides were found to be differentially expressed (p < 0.05) between human lung adenocarcinoma cells (SPC-A1) and human normal epithelial cells (Beas-2B), of which 1592 were upregulated and 1106 were downregulated in the cancer group. These results demonstrate the material’s superior enrichment efficiency in complex biological samples. Full article

Controlled porosity with precise pore sizes in carbon monoliths (CMs) is crucial for optimizing performance in electrochemical energy storage and adsorption applications. This study explores the influence of porosity in CMs, developed from polymer precursors via the sol–gel route, employing soft templating, in situ graphene growth, and post-activation. The effects on CO₂ and H₂ sorption and electrochemical capacitor (EC) performance are analyzed. Graphene is successfully grown in situ from graphene oxide (GO), as confirmed by several characterization analyses. The amount of GO incorporated influences the crosslink density of the polymer gel, generating various pore structures at both micro- and mesoscales, which impacts performance. For instance, CO₂ capture peaks at 5.01 mmol g⁻¹ (0 °C, 101 kPa) with 10 wt % GO, due to the presence of wider micropores that allow access to ultramicropores. For H₂ storage, the best performance is achieved with 5 wt % GO, reaching 12.8 mmol g⁻¹ (−196 °C, 101 kPa); this is attributed to the enlarged micropore volumes between 0.75 and 2 nm that are accessible by mesopores of 2 to 3 nm. In contrast, for the ECs, lower GO loadings (0.5 to 2 wt %) improve ion accessibility via mesopores (4 to 6 nm), enhancing rate capability through better conduction. Full article

The overconsumption of fossil energy sources has resulted in serious environmental impacts and an ensuing energy crisis. Therefore, the search for a new alternative energy technology has become a focus of attention. The long-established Fischer–Tropsch synthesis technology and the recent CO₂ hydrogenation technology with unlimited potential seem to be among the ways to solve the above problems. Among them, the development of efficient Fe-based catalysts has become a key issue. Weaker interactions on carbon supports are more favourable for the formation of active phases in Fe-based catalysts than stronger metal–support interactions on conventional oxide supports. In this work, we systematically summarise the application of various types of carbon materials (carbon nanotubes, mesoporous carbon, graphene, activated carbon, etc.) in CO_x hydrogenation reactions. The effects of different structural types of carriers on the dispersion of active sites are discussed. At the same time, the effects of different carrier preparation methods on catalytic performance are compared. In addition, the role of surface modifications to carbon materials in the promotion of active sites is discussed. Finally, we propose possible research directions based on the current problems in these catalytic systems. The aim is to provide a reference for the development of new carbon materials and their application in CO_x hydrogenation. Full article

The use of graphene oxide (GO) in combination with mesoporous materials has gained interest in the development of adsorbents. In this study, GO was impregnated into zeolite at three concentrations (ZGO2.5, ZGO5, and ZGO10) through a simple thermal process to enhance the adsorption of methylene blue (MB). Characterization of the resulting materials was performed using spectroscopic techniques such as UV-Vis and FT-IR spectroscopy, SEM, and EDS, confirming the presence of GO on zeolite. Batch experiments were conducted to evaluate their performance, analyzing contact time, pH effect, and adsorption kinetics. Pseudo-first-order, pseudo-second-order, and Elovich kinetic models were applied, and the adsorption mechanism was studied using Langmuir, Freundlich, Temkin II, and Dubinin–Radushkevich (D-R) isotherms at different temperatures. Optimal adsorption was achieved at 273 K, 100 mg L⁻¹ of MB, adsorbent mass of 100 mg, 250 rpm, and pH 5–9, with 90% removal efficiency after 70 min. The pseudo-second-order, Freundlich, and D-R models best described the process (R² > 0.98), suggesting a mixed physisorption–chemisorption mechanism. The maximum adsorption capacity from the D-R isotherm reached 119 mg g⁻¹ at 333 K. Thermodynamic studies showed that adsorption was a spontaneous and endothermic process. These findings highlight the potential of GO-impregnated zeolite as an effective adsorbent for MB. Full article

Solar-driven catalytic oxidation processes for the removal of toxic gaseous pollutants have attracted considerable scientific attention, and there is a strong desire to improve the mass transfer, photogenerated charge separation, and O₂ activation by regulating the structure of the photocatalyst. Initially, functionalized graphene–TiO₂ mesoporous hollow nanofibers have been controllably fabricated by a coaxial electrospinning technique, in which functionalized graphene is controllably prepared through a sequential diazonium functionalization and silane modification and ensures its uniform distribution among TiO₂ nanoparticles (NPs). Subsequently, the ultrafine Ag NPs are primarily anchored onto the surface of graphene by an in situ frozen photodeposition strategy, producing Ag/functionalized graphene–TiO₂ mesoporous hollow nanofibers (Ag/SiG-TO MPHNFs). The optimal Ag/SiG-TO MPHNFs exhibit 3.9-fold and 4.6-fold enhancements in CO photooxidation compared with TO MPHNFs and P25 TiO₂, respectively. The enhanced photoactivity can be attributed to three factors: the creation of the mesoporous hollow structure accelerates mass transfer, the incorporation of graphene facilitates the transfer of photogenerated electrons from TiO₂ to graphene, and the anchoring of Ag NPs improves O₂ activation. Full article

Titanium dioxide demonstrates promising potential in the energy storage field due to its high theoretical specific capacity and economic viability. However, its practical application is hindered by intrinsic limitations including low electronic conductivity and slow lithium-ion transport. In general, nature inspires the biotemplating synthesis of artificially functional materials with hierarchical structures. Learning from the bioinspired synthesis process, we adopt a facile biomimetic approach to synthesize graphene-based anatase TiO₂ nanoparticle/nanorod hierarchical structure. The rod-shaped anatase is assembled nanoparticles with a diameter of 20 to 50 nm, and the surface of graphene is deposited by nanoparticles of 5 to 10 nm. The composite also possesses a high surface area and a mesoporous structure. This unique structure not only reduces the transportation pathway of lithium ions and electrons but also enhances the electric conductivity and tolerates the volume change. As an anode electrode, the bioinspired hierarchical structure exhibits a high reversible capacity of 160 mA h g⁻¹ after 180 cycles at a current rate of 1C, highlighting the effectiveness of bioinspired design. Full article

Homogeneous aptasensors that eliminate the need for probe labeling or immobilization hold significant potential for the rapid detection of tumor biomarkers. Herein, a homogeneous aptasensor with electrochemical (EC) and electrochemiluminescence (ECL) dual detection channels was developed by integrating nanochannel-based probe enrichment and DNase I cleavage for selective detection of the tumor biomarker, carbohydrate antigen 125 (CA125). A two-dimensional (2D) composite probe was prepared by assembling the CA125-specific aptamer and the cationic probe tris(2,2′-bipyridyl)Ru(II) (Ru(bpy)₃²⁺), which exhibited both EC and ECL properties, onto graphene oxide (GO) nanosheets (Ru(bpy)₃²⁺/Apt@GO). A vertically ordered mesoporous silica film (VMSF) with ultrasmall, uniform, and vertically aligned nanochannel arrays was rapidly grown on the inexpensive and disposable indium tin oxide (ITO) electrode, forming the detection interface. Due to the size exclusion effect of the ultrasmall nanochannels in VMSF, the Ru(bpy)₃²⁺/Apt@GO probe was unable to penetrate the nanochannels, resulting in no detectable Ru(bpy)₃²⁺ signal on the electrode. Upon specific recognition of CA125 by the aptamer, an aptamer-CA125 complex was formed and subsequently detached from GO. DNase I then cleaved the aptamer-CA125 complex, releasing CA125 and allowing Ru(bpy)₃²⁺ to dissociate into the solution. This enzymatic cleavage enabled CA125 to re-enter the binding cycle, amplifying the release of Ru(bpy)₃²⁺ into the solution. The electrostatic adsorption of the cationic Ru(bpy)₃²⁺ by VMSF significantly enhanced both the EC and ECL signals. The constructed aptasensor exhibited a linear EC detection range for CA125 from 0.1 U/mL to 100 ng/mL, with a limit of detection (LOD) of 91 mU/mL. For ECL detection, CA125 was detected over a range from 0.001 to 100 U/mL, with a LOD as low as 0.4 mU/mL. The developed aptasensor demonstrated excellent selectivity and was successfully applied to the dual-mode EC/ECL detection of CA125 in fetal bovine serum samples. Full article

Dye-sensitization is a promising strategy to improve the light absorption and photoactivity abilities of wide-bandgap semiconductors, like TiO₂. For effective water-splitting photoanodes with no sacrificial agents, the electrochemical potential of the dye must exceed the thermodynamic threshold needed for the oxygen evolution reaction. This study investigates two promising organic cyanoacrylic dyes, designed to meet that criterion by means of theoretical calculations. Both yellow-colored dyes were synthesized and characterized by optical and photoelectrochemical techniques, demonstrating strong light absorption in the visible region, suitable experimental reduction potentials, and adsorption from the organic solvent onto mesoporous TiO₂ layers. In addition, to promote immobilization in aqueous electrolytes, the dyes were hybridized with graphene oxide or multi-walled carbon nanotubes. Photoelectrochemical analysis of the dye-sensitized photoelectrodes demonstrated efficient charge transfer from the dyes to the TiO₂ photoanode under simulated solar light. While the starting photocurrent notably surpassed the blank TiO₂, a subsequent decay points to kinetic obstacles that still need to be overcome. Full article

This review explores the advances in developing adsorbent materials for solid-phase microextraction (SPME), focusing on nanoparticles, nanocomposites, and nanoporous structures. Nanoparticles, including those of metals (e.g., gold, silver), metal oxides (e.g., TiO₂, ZnO), and carbon-based materials (e.g., carbon nanotubes, graphene), offer enhanced surface area, improved extraction efficiency, and increased selectivity compared to traditional coatings. Nanocomposites, such as those combining metal oxides with polymers or carbon-based materials, exhibit synergistic properties, further improving extraction performance. Nanoporous materials, including metal–organic frameworks (MOFs) and ordered mesoporous carbons, provide high surface area and tunable pore structures, enabling selective adsorption of analytes. These advanced materials have been successfully applied to various analytes, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), pesticides, and heavy metals, demonstrating improved sensitivity, selectivity, and reproducibility compared to conventional SPME fibers. The incorporation of nanomaterials has significantly expanded the scope and applicability of SPME, enabling the analysis of trace-level analytes in complex matrices. This review highlights the significant potential of nanomaterials in revolutionizing SPME technology, offering new possibilities for sensitive and selective analysis in environmental monitoring, food safety, and other critical applications. Full article

The NiCo₂O₄ Nanosheets@Carbon fibers composites have been successfully synthesized by a facile co-electrodeposition process. The mesoporous NiCo₂O₄ nanosheets aligned vertically on the surface of carbon fibers and crosslinked with each other, producing loosely porous nanostructures. These hybrid composite electrodes exhibit high specific capacitance in a three-electrode cell. The asymmetric supercapacitor (NiCo₂O₄ Nanosheets@Carbon fibers//Graphene oxide) displayed a high specific capacitance of 91 F g⁻¹ and excellent cycling stability with a capacitance retention of 94.5% at 5 A g⁻¹ after 10,000 cycles. The device also achieved a notable energy density of 52 Wh kg⁻¹ coupled with a power density of 3.5 kW kg⁻¹ and a high power density of 7.1 kW kg⁻¹ with an energy density of 21 Wh kg⁻¹. This study shed light on the great potential of this asymmetric device as future supercapacitor. Full article

Sildenafil is used to treat erectile dysfunction and pulmonary arterial hypertension but is often illicitly added to energy drinks and chocolates. This study introduces a lateral flow strip test using aptamers specific to sildenafil for detecting its illegal presence in food. The process involved using graphene oxide SELEX to identify high-affinity aptamers, which were then converted into molecular gate structures on mesoporous silica nanoparticles, creating a unique signaling system. This system was integrated into lateral flow chromatography strips and tested on buffers and chocolate samples containing sildenafil. The method simplifies the lateral flow assay (LFA) for small molecules and provides a tool for signal amplification. The detection limit for these strips was found to be 68.2 nM (31.8 µg/kg) in spiked food samples. Full article