Search Results (20)

This study introduces nitrogen- and silicon-containing carbon quantum dots (N,Si-CQDs), synthesized hydrothermally from the sustainable bioresource stinging nettle (Urtica dioica L.), as chemically active supports for Pt, Pd, and Pt₃Pd₁ electrocatalysts. The N,Si-CQDs were characterized by a high concentration of N/O surface functionalities and the presence of biogenic Si. A significant finding is that, with this support, biogenic Si acts as a nucleation template: Pd forms in situ as orthorhombic Pd₉Si₂ nanorods alongside spherical particles, whereas Pt predominantly develops as cubic/quasi-cubic crystals. This templating process promotes faceted (cubic) Pt₃Pd₁ alloy nanoparticles with robust interfacial contact with the support and a log-normal size distribution (14.2 ± 4.3 nm) on N,Si-CQDs (4.7 ± 1.4 nm). This configuration enhanced the electrochemically active surface area to 181 m² gPt⁻¹, significantly exceeding those of commercial Pt₁Pd₁/XC-72 (27.7 m² gPt⁻¹) and monometallic Pt/N,Si-CQDs (14.3 m² gPt⁻¹). Consequently, the catalyst demonstrated superior methanol oxidation performance, evidenced by a low onset potential (0.17 V), approximately 10-fold higher mass activity compared to Pt₁Pd₁/XC-72, and 53% activity retention after a 16 h accelerated durability test. The enhanced performance is attributed to the strong nanoparticle anchoring by N,Si-CQDs, the bifunctional/ligand effects of the Pt–Pd alloy that improve CO tolerance, and the templating role of biogenic Si. Full article

Calcium–magnesium (Ca–Mg) carbonates are among the most widely distributed carbonates in the Earth’s surface environment, and their formation mechanisms are of great significance for revealing geological environmental changes and carbon sequestration processes. In this study, the gas diffusion method was employed with L-glutamic acid, L-glycine, and L-lysine as nucleation templates for carbonate minerals to systematically investigate their regulatory effects on the mineralization of Ca–Mg carbonates. The results demonstrated that L-glycine, with the shortest length, was more conducive to forming aragonite, whereas acidic L-glutamic acid, which contains more carboxyl groups, was more beneficial for the structural stability of aragonite. The morphology of the Ca-Mg carbonate minerals became more diverse and promoted the formation of spherical and massive mineral aggregates under the action of amino acids. Moreover, the amino acids significantly increased the MgCO₃ content in Mg calcite (L-glutamic acid: 10.86% > L-glycine: 7.91% > L-lysine: 6.63%). The acidic L-glutamic acid likely promotes the dehydration and incorporation of Mg²⁺ into the Mg calcite lattice through the preferential adsorption of Mg²⁺ via its side-chain carboxyl groups. This study shows how amino acid functional groups influence Ca–Mg carbonate mineralization and provides insights into biogenic Mg-rich mineral origins and advanced mineral material synthesis. Full article

This work shows a sustainable methodology for the synthesis of biogenic materials designed for the removal and photodegradation of rhodamine B (RhB), a highly dangerous environmental pollutant that induces reproductive toxicity. The classical synthesis of MCM-41-ordered mesoporous materials was modified using biocompatible rice husk as the silica template. Iron was incorporated and the so-prepared biogenic photocatalysts were characterized by X-ray diffraction, N₂ adsorption–desorption isotherms, transmission electron microscopy, diffuse reflectance UV-Vis, surface pH, cyclic voltammetry, and Fourier transform infrared spectral analysis of pyridine adsorption. The photocatalytic performance of the materials was evaluated following the removal by adsorption and the photon-driven degradation of RhB. The adsorption capacity and photocatalytic activity of the biogenic materials were correlated with their properties, including iron content, texture, surface content, and electrochemical properties. The best biogenic material boosted the degradation rates of RhB under UV irradiation up to 4.7 and 2.2 times greater than the direct photolysis and the benchmark semiconductor TiO₂-P25. It can be concluded that the use of rice husks for the synthesis of biogenic Fe-modified mesoporous materials is a promising strategy for wastewater treatment applications, particularly in the removal of highly toxic organic dyes. Full article

Based on dual-template molecular imprinting polymerization technology, a fluorescent molecularly imprinted polymer doped with CdSe/ZnS quantum dots was developed to construct a “Turn-on” fluorescence sensor for the rapid, sensitive, and specific detection of two biogenic amines. The biogenic amines bind to the quantum dots, which eliminates surface defects and enhances the fluorescence emission intensity of the quantum dots. By optimizing both the polymerization and detection processes, the results demonstrate that the sensor can detect biogenic amines within the range of 0.01–10 mmol/L, with a low detection limit of 14.57 μmol/L and a detection time of only ten minutes. Moreover, the sensor is cost-effective and does not require specialized instrument operation, offering a practical approach for the rapid detection of biogenic amines in complex food matrices. This study advances the development of simultaneous recognition and rapid detection technologies for multiple target molecules. Full article

For a wide range of applications, paper materials require effective protection against the destructive effect of water, which is most effectively realized by superhydrophobic coatings. In recent years, a considerable amount of scientific research has been carried out in this area, focusing particularly on biogenic resources. With this contribution, we go one step further and examine how biogenic materials can be transferred into aqueous dispersions and coated onto paper via existing technologies. With this paper coating, based on a hydrophobic cellulose derivative in combination with a structurally similar wax, thermally regenerable flower-like surface morphologies are obtained via self-assembly, where the hydrophobic cellulose polymer acts as a structural template for the co-crystallization of the wax component. Such hydrophobic structures in the low micrometer range ensure perfectly water-repellent paper surfaces with contact angles > 150° starting from coating weights of 5 g/m². The dispersion can be successfully applied to a variety of commercially available paper substrates, whereby the effects of different roughness, porosity, and hydrophobicity were investigated. In this context, a certain roughness of the base paper (S_a ~ 1.5–3 µm) was found to be beneficial for achieving the highest possible contact angles. Furthermore, the approach proved to be paper process-compatible, recyclable, and regenerable, whereby the processing temperatures allow the coating properties to be thermally generated in situ. With this work, we demonstrate how biogenic waxes are very well suited for superhydrophobic, regenerative coatings and, importantly, how they can be applied from aqueous coatings, enabling simple transfer into the paper industry. Full article

Polyamines (PAs) are polycationic biogenic amines ubiquitously present in all life forms and are involved in molecular signaling and interaction, determining cell fate (e.g., cell proliferation, dif-ferentiation, and apoptosis). The intricate balance in the PAs’ levels in the tissues will determine whether beneficial or detrimental effects will affect homeostasis. It’s crucial to note that endoge-nous polyamines, like spermine and spermidine, play a pivotal role in our understanding of neu-rological disorders as they interact with membrane receptors and ion channels, modulating neuro-transmission. In spiders and wasps, monoamines (histamine, dopamine, serotonin, tryptamine) and polyamines (spermine, spermidine, acyl polyamines) comprise, with peptides and other sub-stances, the low molecular weight fraction of the venom. Acylpolyamines are venom components exclusively from spiders and a species of solitary wasp, which cause inhibition chiefly of iono-tropic glutamate receptors (AMPA, NMDA, and KA iGluRs) and nicotinic acetylcholine receptors (nAChRs). The first venom acylpolyamines ever discovered (argiopines, Joro and Nephila toxins, and philanthotoxins) have provided templates for the design and synthesis of numerous analogs. Thus far, analogs with high potency exert their effect at nanomolar concentrations, with high se-lectivity toward their ionotropic and ligand receptors. These potent and selective acylpolyamine analogs can serve biomedical purposes and pest control management. The structural modification of acylpolyamine with photolabile and fluorescent groups converted these venom toxins into use-ful molecular probes to discriminate iGluRs and nAchRs in cell populations. In various cases, the linear polyamines, like spermine and spermidine, constituting venom acyl polyamine backbones, have served as cargoes to deliver active molecules via a polyamine uptake system on diseased cells for targeted therapy. In this review, we examined examples of biogenic amines that play an essential role in neural homeostasis and cell signaling, contributing to human health and disease outcomes, which can be present in the venom of arachnids and hymenopterans. With an empha-sis on the spider and wasp venom acylpolyamines, we focused on the origin, structure, derivatiza-tion, and biomedical and biotechnological application of these pharmacologically attractive, chemically modular venom components. Full article

Highly porous layered double hydroxide (LDH) and its calcined mixed metal oxide (MMO) were obtained by utilizing egg white (EW) as a biogenic porous template. The LDH was prepared through coprecipitation under the existence of a beaten EW meringue, and the corresponding MMO was obtained by calcining LDH at 500 °C. According to X-ray diffraction, the crystal structure of LDH and MMO was well-developed with or without EW. In contrast, the crystallinity analyses and microscopic investigations clearly showed differences in the particle orientation in the presence of EW; the protein arrangement in the EW foam induced the ordered orientation of LDH platelets along proteins, resulting in well-developed inter-particle pores. As a result, the distinctive particle arrangement in EW-templated samples compared with non-templated ones showed dramatically enhanced specific surface area and porosity. The nitrogen adsorption–desorption isotherm exhibited that the high specific surface area was attributed to the homogeneous nanopores in EW-templated LDH and MMO, which originated from the sacrificial role of the EW. Full article

The issue of organic contaminants in water resulting from industrial, agricultural, and home activities makes it necessary to effectively address the problems of water scarcity. Using modern technologies that can effectively remove pollutants from wastewater is the way to address this key problem. The use of nanoparticles (NPs) has been advocated due to their unique physical and chemical characteristics and advantageous applications. NPs’ surface stability and synthesis routes are core concerns for environmental remediation and biological applications. In this work, we demonstrated the biogenic synthesis of silver NPs (Ag-CS NPs) by using Caralluma subulata (CS) aqueous extract as a reducing and capping/template agent. The synthesized Ag-CS NPs were characterized by UV-visible absorbance spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, powdered X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Zeta potential. The performance of Ag-CS NPs was evaluated on methylene blue (MB) dye degradation and antibacterial activity tests against bacterial and fungal isolates. The results showed that Ag-CS NPs (0.05%, 20.0 μL) reduced MB by 95.52% within 28 min in the presence of NaBH₄ (10.0 mM, 0.980 μL). The degradation of MB followed pseudo zero-order chemical kinetics (R² = 0.9380), with the reaction rate constant 0.0508 mol L⁻¹ min⁻¹. In addition, Ag-CS NPs were applied as antibacterial agents against 19 bacterial isolates. Ag-CS NPs showed inhibition in both Gram-positive and Gram-negative bacterial, as well as fungal isolates. As a greener ecofriendly approach, multifunctional Ag-CS NPs make a promising candidate for the remediation of contaminated water, as well as for important bioapplications. Full article

Natural product-based structural templates have immensely shaped small molecule drug discovery, and new biogenic natural products have randomly provided the leads and molecular targets in anti-analgesic activity spheres. Pain relief achieved through opiates and non-steroidal anti-inflammatory drugs (NSAIDs) has been under constant scrutiny owing to their tolerance, dependency, and other organs toxicities and tissue damage, including harm to the gastrointestinal tract (GIT) and renal tissues. A new, 3′,4′,6′-triacetylated-glucoside, 2-O-β-D-(3′,4′,6′-tri-acetyl)-glucopyranosyl-3-methyl pentanoic acid was obtained from Ficus populifolia, and characterized through a detailed NMR spectroscopic analysis, i.e., ¹H-NMR, ¹³C-DEPT-135, and the 2D nuclear magnetic resonance (NMR) correlations. The product was in silico investigated for its analgesic prowess, COX-2 binding feasibility and scores, drug likeliness, ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, possible biosystem’s toxicity using the Discovery Studio^®, and other molecular studies computational software programs. The glycosidic product showed strong potential as an analgesic agent. However, an in vivo evaluation, though at strong levels of pain-relieving action, was estimated on the compound’s extract owing to the quantity and yield issues of the glycosidic product. Nonetheless, the F. populifolia extract showed the analgesic potency in eight-week-old male mice on day seven of the administration of the extract’s dose in acetic acid-induced writhing and hot-plate methods. Acetic acid-induced abdominal writhing for all the treated groups decreased significantly (p < 0.0001), as compared to the control group (n = 6) by 62.9%, 67.9%, and 70.9% of a dose of 100 mg/kg (n = 6), 200 mg/kg (n = 6), and 400 mg/kg (n = 6), respectively. Similarly, using the analgesia meter, the reaction time to pain sensation increased significantly (p < 0.0001), as compared to the control (n = 6). The findings indicated peripheral and central-nervous-system-mediated analgesic action of the product obtained from the corresponding extract. Full article

Microbially induced carbonate precipitation (MICP) is an important process in the synthesis of carbonate minerals, and thus, it is widely explored as a novel approach with potential for many technological applications. However, the processes and mechanisms involved in carbonate mineral formation in the presence of microbes are not yet fully understood. This review covers the current knowledge regarding the role of microbial cells and metabolic products (e.g., extracellular polymeric substances, proteins and amino acids) on the adsorption of divalent metals, adsorption of ionic species and as templates for crystal nucleation. Moreover, they can play a role in the mineral precipitation, size, morphology and lattice. By understanding how microbes and their metabolic products promote suitable physicochemical conditions (pH, Mg/Ca ratio and free CO₃²⁻ ions) to induce carbonate nucleation and precipitation, the manipulation of the final mineral precipitates could be a reality for (geo)biotechnological approaches. The applications and implications of biogenic carbonates in areas such as geology and engineering are presented and discussed in this review, with a major focus on biotechnology. Full article

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (_nSi). The synthesized silica nanoparticles (_nSi) were characterized by ultraviolet–visible (UV–Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of the _nSi composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks for _nSi and confirmed the formation of an amorphous nature. The average size of _nSi obtained is 18 nm. The surface charge and stability of _nSi were analyzed by using the dynamic light scattering (DLS) and thus revealed that the _nSi samples have a negative charge (−20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using the _nSi. The results revealed that the application of _nSi enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenic _nSi before mass production and use of agricultural applications. Full article

One of the undeniable trends in modern bioengineering and nanotechnology is the use of various biomolecules, primarily of a polymeric nature, for the design and formulation of novel functional materials for controlled and targeted drug delivery, bioimaging and theranostics, tissue engineering, and other bioapplications. Biocompatibility, biodegradability, the possibility of replicating natural cellular microenvironments, and the minimal toxicity typical of biogenic polymers are features that have secured a growing interest in them as the building blocks for biomaterials of the fourth generation. Many recent studies showed the promise of the hard-templating approach for the fabrication of nano- and microparticles utilizing biopolymers. This review covers these studies, bringing together up-to-date knowledge on biopolymer-based multilayer capsules and beads, critically assessing the progress made in this field of research, and outlining the current challenges and perspectives of these architectures. According to the classification of the templates, the review sequentially considers biopolymer structures templated on non-porous particles, porous particles, and crystal drugs. Opportunities for the functionalization of biopolymer-based capsules to tailor them toward specific bioapplications is highlighted in a separate section. Full article

Alzheimer’s disease (AD) is the most prevalent form of dementia. Improving the amount of acetylcholine in the brain is an efficient way to treat the illness. The global incidence of dementia is estimated to be as high as 50 million, and it is expected to increase every 20 years until 2040, resulting in a costly burden of disease. Early-life risk factors for pathology include genes, chromosomal abnormalities, head injury, insulin resistance, and inflammation. Potentially modifiable risk factors including obesity, diabetes, hypertension, and smoking are associated with Alzheimer’s disease (AD) and represent promising targets for intervention. The drugs currently being used to manage AD have various drawbacks. The chemical inhibition of cholinesterase enzymes is an effective technique for treating signal related neuropathology, and possible sources of compounds with these properties are natural products and biogenic metal oxide nanoparticles. There is a potential source of AChE and BChE inhibitors in the abundance of plants in nature, and natural goods appear to offer useful medications and templates for the development of other compounds. This dissertation represents a review of the literature on species of medicinal plants and nanomaterial related plants tested for their inhibitory action of AChE and BChE. Plant species and the plant-mediated metal oxide nanoparticles referred to are possible cholinesterase inhibitors and can assist researchers in their study of natural products that may be beneficial in the treatment of AD. Full article

The bone remodeling field has shifted focus towards the delineation of products with two main critical attributes: internal architectures capable to promote fast cell colonization and good mechanical performance. In this paper, Luffa-fibers and graphene nanoplatelets were proposed as porogen template and mechanical reinforcing agent, respectively, in view of framing 3D products by a one-stage polymer-free process. The ceramic matrix was prepared through a reproducible technology, developed for the conversion of marble resources into calcium phosphates (CaP) powders. After the graphene incorporation (by mechanical and ultrasonication mixing) into the CaP matrix, and Luffa-fibers addition, the samples were evaluated in both as-admixed and thermally-treated form (compact/porous products) by complementary structural, morphological, and compositional techniques. The results confirmed the benefits of the two agents’ addition upon the compact products’ micro-porosity and the global mechanical features, inferred by compressive strength and elastic modulus determinations. For the porous products, overall optimal results were obtained at a graphene amount of <1 wt.%. Further, no influence of graphene on fibers’ ability to generate at high temperatures internal interconnected-channels-arrays was depicted. Moreover, its incorporation led to a general preservation of structural composition and stability for both the as-admixed and thermally-treated products. The developed CaP-reinforced structures sustain the premises for prospective non- and load-bearing biomedical applications. Full article

Chitosan is a natural, biodegradable cationic polysaccharide, which has a similar chemical structure and similar biological behaviors to the components of the extracellular matrix in the biomineralization process of teeth or bone. Its excellent biocompatibility, biodegradability, and polyelectrolyte action make it a suitable organic template, which, combined with biomimetic mineralization technology, can be used to develop organic-inorganic composite materials for hard tissue repair. In recent years, various chitosan-based biomimetic organic-inorganic composite materials have been applied in the field of bone tissue engineering and enamel or dentin biomimetic repair in different forms (hydrogels, fibers, porous scaffolds, microspheres, etc.), and the inorganic components of the composites are usually biogenic minerals, such as hydroxyapatite, other calcium phosphate phases, or silica. These composites have good mechanical properties, biocompatibility, bioactivity, osteogenic potential, and other biological properties and are thus considered as promising novel materials for repairing the defects of hard tissue. This review is mainly focused on the properties and preparations of biomimetically mineralized composite materials using chitosan as an organic template, and the current application of various chitosan-based biomimetically mineralized composite materials in bone tissue engineering and dental hard tissue repair is summarized. Full article