Search Results (398)

Plasma surface modification has emerged as a powerful, versatile tool for tailoring the surface properties of biomedical devices and implants without altering the material characteristics in the bulk. This comprehensive review critically examines the current state-of-the-art in plasma-based surface engineering techniques, with a focus on enhancing biocompatibility, bio-functionality, and long-term performance of medical implants. The article systematically explores various plasma processes and their roles in modifying surface chemistry, topography, energy, and wettability. These alterations directly influence protein adsorption, cell adhesion, antibacterial activity, and corrosion resistance, all of which are crucial for successful clinical integration. Special emphasis is placed on the plasma treatment of metallic (e.g., titanium, stainless steel), polymeric (e.g., polytetrafluoroethylene, polyetheretherketone), and composite substrates commonly used in dental, orthopedic, and cardiovascular applications. This review also highlights synergistic strategies, such as plasma-assisted grafting of bioactive molecules and nanostructuring, that enable multifunctional surfaces capable of promoting osseointegration, mitigating inflammation, and preventing biofilm formation. Emerging trends such as atmospheric cold plasmas and the integration of plasma technology with additive manufacturing are outlined as promising future directions. By synthesizing insights from surface science, materials engineering, and biomedical research, this review provides a foundational framework to guide future innovations in plasma-treated biomaterials. It aims to inform both academic researchers and medical device developers seeking to optimize implant–tissue interactions and achieve improved clinical outcomes. Full article

In today’s chemistry, greener and more energy-efficient ways of making new materials are becoming increasingly important. In this work, two types of (3-aminopropyl) triethoxysilane-grafted silica were synthesized using a one-pot method with two different porogens: Pluronic P123 and cetyltrimethylammonium bromide, and then modified with silver nanoparticles. Both syntheses produced amorphous silica with crystalline silver. EDX and EDX elemental mapping confirmed that the modification with silver nanoparticles was successful, and an even distribution of silver on the silica surface with an average silver load of around 16% was determined. After silver nanoparticle modification, silica synthesized using cetyltrimethylammonium bromide as a porogen was mesoporous, whereas silica synthesis using Pluronic P123 as a porogen yielded a nonporous product. The synthesized silicas exhibited surface areas of 345 ± 2 and 8.80 ± 0.05 m²/g for samples prepared using cetyltrimethylammonium bromide and Pluronic P123 as porogens, respectively, and both silicas were stable below 250 °C. Full article

In recent years the global market of nanomedicine has experienced incredible growth owing to the advances in the field. This translation of the technique to the biomedical industry requires the development of production methods that deliver nanomedicines with a high degree of reproducibility between batches, combined with cost and time efficiency. The use of nanoparticles in medicine usually requires their surface functionalization to improve biocompatibility in addition to providing targeting capacities and/or stimuli-responsive behavior, among other interesting skills. Microfluidic technology has revolutionized the field both in nanomedicine synthesis and in preclinical evaluation. However, microfluidic-assisted synthetic procedures commonly require high-cost methods and equipment to fabricate the microreactors. The aim of this work is to present an ultra-low-cost microfluidic platform that permits the versatile modification of nanomaterials. To prove this approach, two different model nanoparticles with different natures: soft nanoparticles (liposomes) and rigid nanoparticles (mesoporous silica) have been decorated both with small molecules and with other nanoparticles, respectively, in order to evaluate the scope of this approach. The anchoring of the covalently attached elements has been performed using click chemistry, in compliance with the principles for further transfer to the drug industry. Full article

Metal–organic frameworks (MOFs) have been increasingly recognized as promising platforms for enzyme modulation, owing to their tunable porosity, high surface area, and versatile chemical functionality. In this review, the potential of MOFs for the inhibition and modulation of protein kinases and phosphatases—key regulators of cellular signaling and disease progression—is examined. The structural fundamentals of MOFs are outlined, followed by a discussion of common synthesis strategies, including solvothermal, microwave-assisted, sonochemical, and mechanochemical methods. Emphasis is placed on how synthesis conditions influence critical features such as particle size, crystallinity, surface chemistry, and functional group accessibility, all of which impact biological performance. Four primary mechanisms of MOF–enzyme interaction are discussed: surface adsorption, active site coordination, catalytic mimicry, and allosteric modulation. Each mechanism is linked to distinct physicochemical parameters, including pore size, surface charge, and metal node identity. Special focus is given to biologically relevant metal centers such as Zr⁴⁺, Ce⁴⁺, Cu²⁺, Fe³⁺, and Ti⁴⁺, which have been shown to contribute to both MOF stability and enzymatic inhibition through Lewis acid or redox-mediated mechanisms. Recent in vitro studies are reviewed, in which MOFs demonstrated selective inhibition of disease-relevant enzymes with minimal cytotoxicity. Despite these advancements, several limitations have been identified, including scalability challenges, limited physiological stability, and potential off-target effects. Strategies such as post-synthetic modification, green synthesis, and biomimetic surface functionalization are being explored to overcome these barriers. Through an integration of materials science, coordination chemistry, and molecular biology, this review aims to provide a comprehensive perspective on the rational design of MOFs for targeted enzyme inhibition in therapeutic contexts. Full article

Titanium-containing nanoparticles have emerged as materials of significant technological importance due to their multifunctional properties and excellent performance. With their expanding applications, the amount of TiO₂ nanoparticles (TNPs) being released into the soil environment has increased significantly. This review addresses the gap in current research, which has predominantly focused on the environmental behavior of TNPs in aquatic systems while lacking systematic integration of the synergetic mechanism of adsorption–transformation–ecological effects in soil systems and its guiding value for practical applications. It deeply reveals the interaction mechanisms between TNPs and environmental pollutants. TNPs exhibit outstanding adsorption performance towards environmental pollutants such as heavy metals and organic compounds. Specifically, the maximum adsorption capacities of titanate nanowhiskers for the heavy metal ions Cu(II), Pb(II), and Cr(III) are 143.9 mg·g⁻¹, 384.6 mg·g⁻¹, and 190.8 mg·g⁻¹, respectively. Additionally, 1-hydroxydinaphthoic acid surface-modified nano-TiO₂ exhibits an adsorption rate of up to 98.6% for p-nitrophenol, with an enrichment factor of 50-fold. The transformation process of TNPs after pollutant adsorption profoundly affects their environmental fate, among which pH is a critical controlling factor: when the environmental pH is close to the point of zero charge (pHpzc = 5.88), TNPs exhibit significant aggregation behavior and macroscopic sedimentation. Meanwhile, factors such as soil solution chemistry, dissolved organic matter, and microbial activities collectively regulate the aggregation, aging, and chemical/biological transformation of TNPs. In the soil ecosystem, TNPs can exert both beneficial and detrimental impacts on various soil organisms, including bacteria, plants, nematodes, and earthworms. The beneficial effects include alleviating heavy metal stress, serving as a nano-fertilizer to supply titanium elements, and acting as a nano-pesticide to enhance plants’ antiviral capabilities. However, excessively high concentrations of TiO₂ can stimulate plants, induce oxidative stress damage, and impair plant growth. This review also highlights promising research directions for future studies, including the development of safer-by-design TNPs, strategic surface modifications to enhance functionality and reduce risks, and a deeper understanding of TNP–soil microbiome interactions. These avenues are crucial for guiding the sustainable application of TNPs in soil environments. Full article

Comets are chemically rich and thermally extreme, spanning surface temperatures from ~50 K in the Oort Cloud to >1000 K for sungrazing bodies. These conditions may support key steps of prebiotic chemistry, including the synthesis of nucleic acid precursors. This study present a thermodynamic evaluation of seven candidate reactions, producing nitrogenous bases, sugars, nucleosides, and nucleotides, across the cometary temperature spectrum, 50–1000 K. Purine nucleobase synthesis, including adenine formation via aminoacetonitrile polymerization and HCN polymerization, is strongly exergonic at all temperatures. Sugar formation from formaldehyde is also exergonic, while intermediate pathways, e.g., 2-aminooxazole synthesis, become thermodynamically viable only above ~700 K. Nucleoside formation is thermodynamically neutral at low T but becomes favorable at elevated temperatures, whereas phosphorylation to AMP, i.e., adenosine-monophosphate, a nucleotide serving as a critical regulator of cellular energy status, remains highly endergonic under the entire T range studied. My analysis suggests that, under standard-state assumptions, comets can thermodynamically support formation routes of nitrogenous bases and simple sugars but not a complete nucleotide assembly. This supports a dual-phase origin scenario, where comets act as molecular reservoirs, with further polymerization and biological activation occurring post-delivery on planetary surfaces. Importantly, these findings represent purely thermodynamic assessments under standard-state assumptions and do not address kinetic barriers, catalytic influences, or adsorption effects on ice or mineral surfaces. The results should therefore be viewed as a baseline map of feasibility, subject to modifications in more complex chemical environments. Full article

This study presents a novel dual-temperature synthesis strategy for cobalt, zinc, and iron-based metal–organic frameworks (MOFs) integrated with tannic acid (TA) surface modification to enhance oxygen evolution reaction (OER) performance. MOFs were synthesized at room temperature and 80 °C, enabling controlled crystal growth and distinct morphologies. Subsequent TA treatment effectively tuned surface chemistry without altering core crystallinity, as confirmed by PXRD, FT-IR, and XPS analyses. Surface modification introduced oxygen-containing functional groups, improved charge transfer, and increased active-site accessibility. Among the catalysts, the tannic acid-modified Fe-based MOF synthesized at 80 °C (TAFeM-2) exhibited outstanding OER activity, achieving an overpotential of only 254 mV at 10 mA cm⁻², outperforming benchmark RuO₂ (276 mV) and unmodified counterparts. Tafel slope analysis revealed faster reaction kinetics for surface-tuned MOFs, while electrochemical impedance spectroscopy indicated reduced charge-transfer resistance (12 Ω for TAFeM-2). Chronoamperometry demonstrated exceptional long-term stability, maintaining constant current density over 20 h with minimal performance loss. Post-OER characterization suggested surface oxidation to iron oxyhydroxides without significant structural degradation. This work demonstrates that combining dual-temperature synthesis with TA surface engineering yields MOF-based catalysts with superior activity, conductivity, and durability, offering a promising pathway for developing high-performance electrocatalysts for sustainable energy applications. Full article

The recent SARS-CoV-2 pandemic has highlighted the need for quickly adaptable technologies in vaccine manufacturing. This can be achieved through virus-like particles (VLPs) as presentation platforms for target antigens. In this study, we investigated the purification of VLPs of the Hepatitis B Core antigen (HBc) and the SplitCore (SplCo) technology. The outer surface protein C (OspC) of Borrelia burgdorferi was genetically fused to HBc and its N-terminal SplCo protein. Product solubility in E. coli increased from 40% for HBc-OspC to 90% for SplCo-OspC. This could not be reproduced with similar SARS-CoV-2 receptor-binding domain fusions due to inclusion body formation. Hydrophobicity was found to be significantly lowered for the OspC fusions, in particular for the SplCo variant. Pre-purified samples were generated by precipitating soluble cell lysate. Subsequently, solubilized precipitates were subjected to anion exchange chromatography (AEX), and the elution fractions obtained contained VLPs, albeit with low purity. The VLPs were also disassembled prior to AEX for dissociative purification, but a subsequent reassembly could not be achieved for both fusion variants. A novel HBc variant was constructed for post-translational modification via click-chemistry. The solubility and hydrophobicity of this HBc variant remained high, but native AEX resulted in complete product loss. By contrast, a yield of 84% VLPs was obtained for the modified HBc after dissociative AEX. The surface-exposed azide group on the particles, introduced for click-chemistry, enabled coupling to fluorophores without compromising VLP stability. Conjugation efficiencies of up to 59% were obtained. These results suggest the potential of combining HBc and click-chemistry for future applications, e.g., the presentation of immunogenic epitopes or antigens. This underlines that for every antigen, both the optimal scaffold-decoration strategy and the subsequent manufacturing process should be carefully selected. Full article

This study explores the use of mid-infrared (MIR) free-electron laser (FEL) irradiation as a tool for tailoring the surface properties of electrochemically synthesized TiO₂—graphene quantum dots (QDs). The QDs, prepared in colloidal form via a cost-effective electrochemical method in a KCl—citric acid medium, were exposed to MIR wavelengths (5.76, 8.02, and 9.10 µm) at the Kyoto University FEL facility. Post-irradiation measurements revealed a pronounced inversion of zeta potential by 40–50 mV and approximately 10% reduction in hydrodynamic size, indicating double-layer contraction and ionic redistribution at the QD—solvent interface. Photoluminescence spectra showed enhanced emission for GQDs and TiO₂/GQD composites, while Tauc analysis revealed modest bandgap blue shifts (0.04–0.08 eV), both consistent with trap-state passivation and sharper band edges. TEM confirmed intact crystalline structures, verifying that FEL-induced modifications were confined to surface chemistry rather than bulk lattice damage. Taken together, these results demonstrate that MIR FEL irradiation provides a resonance-driven, non-contact method to reorganize ions, suppress defect states, and improve the optoelectronic quality of QDs. This approach offers a scalable post-synthetic pathway for enhancing electron transport layers in perovskite solar cells and highlights the broader potential of photonic infrastructure for advanced nanomaterial processing and interface engineering in optoelectronic and energy applications. Full article

The global transition to a circular bioeconomy is accelerating the demand for sustainable, high-performance materials. Filamentous fungi represent a promising solution, as they function as living foundries that transform low-value biomass into advanced, self-assembling materials. While mycelium-based composites have proven potential, progress has been predominantly driven by empirical screening of fungal species and substrates. To unlock their full potential, a paradigm shift from empirical screening to rational design is required. This review introduces a conceptual framework centered on the biochemical programming of the fungal cell wall. Viewed through a materials science lens, the cell wall is a dynamic, hierarchical nanocomposite whose properties can be deliberately tuned. We analyze the contributions of its principal components—the chitin–glucan structural scaffold, the glycoprotein functional matrix, and surface-active hydrophobins—to the bulk characteristics of mycelium-derived materials. We then identify biochemical levers for controlling these properties. External factors such as substrate composition and environmental cues (e.g., pH) modulate cell wall architecture through conserved signaling pathways. Complementing these, an internal synthetic biology toolkit enables direct genetic and chemical intervention. Strategies include targeted engineering of biosynthetic and regulatory genes (e.g., CHS, AGS, GCN5), chemical genetics to dynamically adjust synthesis during growth, and modification of surface chemistry for specialized applications like tissue engineering. By integrating fungal cell wall biochemistry, materials science, and synthetic biology, this framework moves the field from incidental discovery toward the intentional creation of smart, functional, and sustainable mycelium-based materials—aligning material innovation with the imperatives of the circular bioeconomy. Full article

Rapid and accurate bacteria identification, particularly Escherichia coli (E. coli), is essential in the monitoring of health, environment, and food safety. E. coli, a prevalent pathogenic bacterium, serves as a key indicator of food and water contamination. Carbon quantum dots (CQDs) have appeared as promising fluorescent probes because of their small size, ease of synthesis, low toxicity, and tunable fluorescence using different carbon-rich precursors. Advances in both bottom-up and top-down synthesis procedures have enabled precise control over CQD properties and surface functionalities, enhancing their capabilities in biosensing. Among the critical factors influencing CQD performance is the strategic selection of precursors, which determines the surface chemistry and recognition potential of the resulting nanodots. The integration with other nanomaterials and the surface modification of CQDs with specific functional groups or recognition elements further improves their sensitivity and selectivity toward E. coli. This review summarizes recent progress in the modification of CQDs for the fluorescent detection of E. coli, highlighting relevant sensing mechanisms and the influence of different precursors, such as antibiotics and sugars, as well as various functionalization and surface modification strategies. The aim is to provide insight into the rational design of efficient, selective, and cost-effective CQD-based biosensors for bacterial detection. Full article

The present work is aimed at shedding light on the evolution of surface chemistry of a commercial activated carbon (AC) support during the preparation of supported metal oxide (MO) catalysts by the conventional wet impregnation method. Particular attention is paid to the chemical changes of oxygen-containing surface functionalities across three preparation stages of impregnation, oven-drying, and thermal treatment. AC was impregnated with aqueous solutions of several MO precursors (Al(NO₃)₃, Fe(NO₃)₃, Zn(NO₃)₂, SnCl₂, and Na₂WO₄) at 80 °C for 5 h, oven-dried at 120 °C for 24 h, and heat-treated at 200 °C and 850 °C for 2 h under an inert atmosphere. The surface chemistry of the resulting catalyst samples, classified in three series by the thermal treatment, was mainly studied by FT-IR spectroscopy, complemented by elemental analysis and pH of the point of zero charge (pH_pzc) measurements. During impregnation, phenolic hydroxyl and carboxylic acid groups were predominantly formed by wet oxidation of chromene, 2-pyrone, and ether-type structures found in the pristine AC. The extent of these oxidations correlated with the oxidising power of the precursor solutions. As expected, thermal treatment at 850 °C brought about markedly stronger chemical changes, with most of the above oxygen functionalities decomposing and forming less acidic structures, such as 4-pyrone groups, metal carboxylates, and C-O-M atomic groupings. All these surface chemical modifications result in a lowering of the strong basicity of the raw carbon support (pH_pzc ≈ 10.5), thus leading to pH_pzc values for the catalysts widely ranging from 1.6 to 9.7. Full article

This study investigates how the inclusion of refuse-derived fuel (RDF) alters the surface chemistry and electrostatic behavior of oak-based biochar. Biochars were produced using downdraft gasification at 850 °C from 100% oak (HW) and a ternary blend comprising 50% oak, 30% pine, and 20% RDF (HW/SW/RDF). Characterization using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), zeta potential, pH, and electrophoretic mobility was conducted to assess surface functionality and colloidal behavior. The RDF-containing biochar exhibited a 43.3% increase in surface nitrogen content (from 0.24% to 0.90%) and a 6.6% rise in calcium content (from 2.07% to 2.27%) alongside the introduction of chlorine (0.20%) and elevated silicon levels (0.69%) compared to RDF-free counterparts. A concurrent reduction in oxygen-containing functional groups was observed, as O1s decreased from 15.75% in HW to 13.37% in HW/SW/RDF. Electrokinetic measurements revealed a notable decrease in zeta potential magnitude from −31.5 mV in HW to −24.2 mV in HW/SW/RDF, indicating diminished surface charge and colloidal stability. Moreover, the pH declined from 10.25 to 7.76, suggesting a loss of alkalinity and buffering capacity. These compositional and electrostatic shifts demonstrate that RDF inclusion significantly modifies the surface reactivity of biochar, influencing its performance in catalysis, ion exchange, and nutrient retention. The findings underscore the need for tailored post-treatment strategies to enhance the functionality of RDF-modified biochars in environmental applications. Full article

Magnesium alloys have been recently recognized as promising materials for temporary orthopedic applications, thanks to their biocompatibility, nontoxicity and biodegradability, combined with bone-like mechanical properties; nevertheless, their clinical viability is still hindered by their excessively rapid corrosion in physiological environments. In this context, hydrothermal surface modification offers a simple and inexpensive option to form thick ceramic conversion films capable of protecting magnesium and delaying the initial stages of corrosion. In this study, magnesium samples were hydrothermally treated in various aqueous baths to systematically assess the influence of their chemistry on the resulting coating features. The obtained coatings were characterized in terms of physicochemical properties, electrochemical corrosion behavior in SBF, and long-term degradation with volumetric loss quantification by µ-CT. The results highlighted how corrosion resistance is dictated by coating uniformity rather than thickness. Moreover, XRD analyses revealed that all the best-performing coatings contained a stable magnesium oxide phase in addition to magnesium hydroxide, a feature absent in less protective films. A simple sodium nitrate solution was found to produce the most protective layer, showing the lowest volumetric losses after immersion testing. Full article

Cellulose nanocrystals (CNCs), derived from renewable cellulose sources, have emerged as a versatile class of nanomaterial with exceptional mechanical strength, tuneable surface chemistry and inherent biocompatibility. In the scenario of contemporary commercial hydrogel products, which are expensive and rely on synthetic materials, the sustainable origin and unique physicochemical properties have positioned CNCs as promising sustainable functional building blocks for next-generation hydrogels in biomedical applications. Over the past decade, CNC-based hydrogels have gained momentum as soft biomaterials capable of interacting with diverse tissue types, predominantly demonstrated through in vitro cell line studies. This review critically examines the current landscape of research on biomedical applications of CNC-based hydrogels, focusing on their biomedical utility across 22 systematically screened studies. It revealed applications spanning around bone and cartilage tissue engineering, wound healing, medical implants and sensors, and drug delivery. We highlight the predominance of microcrystalline cellulose as the CNC source and sulfuric acid hydrolysis as the preferred extraction method, with several studies incorporating surface modifications to enhance functionality. Despite growing interest, there remains a lack of data for transitioning towards human clinical studies and commercialisation. Hence, this review highlights the pressing need for scalable, sustainable, and affordable CNC-based hydrogel systems that can democratise access to advanced biomedical technologies. Full article