Nanoarchitectonics of an acetogenin-enriched nanosystem mediated by an aqueous extract ofAnnona cherimolaMill with anti-inflammatory and proapoptotic activity against HepG2 cell line.

For the first time, this study shows the nanoarchitectonic process to obtain an acetogenin-enriched nanosystem (AuNPs-Ac) using an aqueous extract fromAnnona cherimolaMill (ACM) composed of gold nanoparticles embedded in an organic matrix that acts as stabilizing agent and presents anti-inflammatory activity and cytotoxical effect against HepG2 cell line, promoting apoptosis. The synthesis of AuNPs-Ac was confirmed by x-ray diffraction analysis, showing metallic gold as the only phase, and the scanning transmission microscope showed an organic cap covering the AuNPs-Ac. Fourier-transformed infrared suggests that the organic cap comprises a combination of different annonaceous acetogenins, alkaloids, and phenols by the presence of bands corresponding to aromatic rings and hydroxyl groups. High-Performance Liquid Chromatography has demonstrated the presence of annonacin, a potent acetogenin, in the extract of ACM. Anin vitroanti-inflammatory activity of the extract of ACM and the AuNPs-Ac was performed using the albumin denaturation method, showing a nonlinear response, which is better than sodium diclofenac salt in a wide range of concentrations that goes from 200 to 400µg ml-1with both samples. The viability assay was studied using trypan blue, treating IMR90 and HepG2 at different concentrations of AuNPs-Ac. The results defined a median lethal dose of 800µg ml-1against HepG2 through apoptosis according to the ratio of caspase-cleaved 9/alpha-tubulin evaluated. It was also demonstrated that the nanosystem presents a higher cytotoxic effect on the HepG2 cell line than in IMR90, suggesting a targeted mechanism. In addition, the nanosystem performs better than using only the extract of ACM in the anti-inflammatory or antiproliferative test, attributed to their higher surface area.

Sargassum natans I Algae: An Alternative for a Greener Approach for the Synthesis of ZnO Nanostructures with Biological and Environmental Applications.

In this work, the influence of the Sargassum natans I alga extract on the morphological characteristics of synthesized ZnO nanostructures, with potential biological and environmental applications, was evaluated. For this purpose, different ZnO geometries were synthesized by the co-precipitation method, using Sargassum natans I alga extract as stabilizing agent. Four extract volumes (5, 10, 20, and 50 mL) were evaluated to obtain the different nanostructures. Moreover, a sample by chemical synthesis, without the addition of extract, was prepared. The characterization of the ZnO samples was carried out by UV-Vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. The results showed that the Sargassum alga extract has a fundamental role in the stabilization process of the ZnO nanoparticles. In addition, it was shown that the increase in the Sargassum alga extract leads to preferential growth and arrangement, obtaining well-defined shaped particles. ZnO nanostructures demonstrated significant anti-inflammatory response by the in vitro egg albumin protein denaturation for biological purposes. Additionally, quantitative antibacterial analysis (AA) showed that the ZnO nanostructures synthesized with 10 and 20 mL of extract demonstrated high AA against Gram (+) S. aureus and moderate AA behavior against Gram (-) P. aeruginosa, depending on the ZnO arrangement induced by the Sargassum natans I alga extract and the nanoparticles' concentration (ca. 3200 µg/mL). Additionally, ZnO samples were evaluated as photocatalytic materials through the degradation of organic dyes. Complete degradation of both methyl violet and malachite green were achieved using the ZnO sample synthesized with 50 mL of extract. In all cases, the well-defined morphology of ZnO induced by the Sargassum natans I alga extract played a key role in the combined biological/environmental performance.

Antibacterial and Anti-Inflammatory Properties of ZnO Nanoparticles Synthesized by a Green Method Using Sargassum Extracts.

The present work shows the synthesis of ZnO nanoparticles through a green method, using sargassum extracts, which provide the reducing and stabilizing compounds. The conditions of the medium in which the reaction was carried out was evaluated, that is, magnetic stirring, ultrasound assisted, and resting condition. UV-Vis, FTIR spectroscopy, and X-ray diffraction results confirmed the synthesis of ZnO with nanometric crystal size. The scanning electron microscopy analysis showed that the morphology and size of the particles depends on the synthesis condition used. It obtained particles between 20 and 200 nm in the sample without agitation, while the samples with stirring and ultrasound were 80 nm and 100 nm, respectively. ZnO nanoparticles showed antibacterial activity against Gram-positive S. aureus and Gram-negative P. aeruginosa. A quantitative analysis was performed by varying the concentration of ZnO nanoparticles. In all cases, the antibacterial activity against Gram-positives was greater than against Gram-negatives. Ultrasound-assisted ZnO nanoparticles showed the highest activity, around 99% and 80% for S. aureus and P. aeruginosa, respectively. Similar results were obtained in the study of the anti-inflammatory activity of ZnO nanoparticles; the ultrasound-assisted sample exhibited the highest percentage (93%), even above that shown by diclofenac, which was used as a reference. Therefore, the ZnO nanoparticles synthesized with sargassum extracts have properties that can be used safely and efficiently in the field of biomedicine.

The Sabatier principle as a tool for discovery and engineering of industrial enzymes.

The recent breakthrough in all-atom, protein structure prediction opens new avenues for a range of computational approaches in enzyme design. These new approaches could become instrumental for the development of technical biocatalysts, and hence our transition toward more sustainable industries. Here, we discuss one approach, which is well-known within inorganic catalysis, but essentially unexploited in biotechnology. Specifically, we review examples of linear free-energy relationships (LFERs) for enzyme reactions and discuss how LFERs and the associated Sabatier Principle may be implemented in algorithms that estimate kinetic parameters and enzyme performance based on model structures.

Ecofriendly and sustainable Sargassum spp.-based system for the removal of highly used drugs during the COVID-19 pandemic.

Analgesic consumption increased significantly during the COVID-19 pandemic. A high concentration of this kind of drug is discarded in the urine, reaching the effluents of rivers, lakes, and seas. These medicines have brought serious problems for the flora and, especially, the ecosystems' fauna. This paper presents the results of removing diclofenac, ibuprofen, and paracetamol in an aqueous solution, using Sargassum spp. from the Caribbean coast. The study consisted of mixing each drug in an aqueous solution with functionalized Sargassum spp in a container under constant agitation. Therefore, this work represents an alternative to solve two of the biggest problems in recent years; first, the reduction of the overpopulation of sargassum through its use for the remediation of the environment. Second is the removal of drug waste used excessively during the COVID-19 pandemic. Liquid samples of the solution were taken at intervals of 10 min and analyzed by fluorescence to determine the concentration of the drug. The sorption capacity for diclofenac, ibuprofen, and paracetamol was 2.46, 2.08, and 1.41 µg/g, corresponding to 98 %, 84 %, and 54 % of removal, respectively. The removal of the three drugs was notably favored by increasing the temperature to 30 and 40 °C, reaching efficiencies close to 100 %. Moreover, the system maintains its effectiveness at various pH values. In addition, the Sargassum used can be reused for up to three cycles without reducing its removal capacity. The wide diversity of organic compounds favors the biosorption of drugs, removing them through various kinetic mechanisms. On the other hand, the Sargassum used in the drugs removal was analyzed by X-ray diffraction, FTIR spectroscopy, TGA analysis, and scanning electron microscopy before and after removal. The results showed an evident modification in the structure and morphology of the algae and demonstrated the presence of the biosorbed drugs. Therefore, this system is sustainable, simple, economical, environmentally friendly, highly efficient, and scalable at a domestic and industrial level that can be used for aquatic remediation environments.

Green Synthesis of Homogeneous Gold Nanoparticles Using Sargassum spp. Extracts and Their Enhanced Catalytic Activity for Organic Dyes.

Sargassum species-based extracts were used to carry out the synthesis of homogeneous gold nanoparticles. Various techniques were used to determine the characteristics and composition of the nanoparticles. The UV-Vis results showed that the 50% water/ethanol extract had the most reducing agents and stabilizers. Therefore, this type of extract was used to synthesize nanoparticles and for their subsequent characterization. Crystallinity and crystal size were evaluated using X-ray diffraction. Size and morphology were analyzed using scanning electron microscopy, showing that the gold nanoparticles were mostly spherical, with a size range of 15-30 nm. The catalytic activity of the gold nanoparticles was evaluated through the degradation of organic dyes: methylene blue, methyl orange, and methyl red. The degradation rates were different, depending on the nature of each dye, the simplest to degrade was methylene blue and methyl red was the most difficult to degrade. The results indicated that the use of Sargassum spp. for the synthesis of gold nanoparticles has potential in the remediation of water that is contaminated with organic dyes. Moreover, given the recent serious environmental and economic problems caused by the overpopulation of Sargassum spp. in the Mexican Caribbean, the findings hold promise for their practical and sustainable use in the synthesis of nanomaterials.

Physical constraints and functional plasticity of cellulases.

Enzyme reactions, both in Nature and technical applications, commonly occur at the interface of immiscible phases. Nevertheless, stringent descriptions of interfacial enzyme catalysis remain sparse, and this is partly due to a shortage of coherent experimental data to guide and assess such work. In this work, we produced and kinetically characterized 83 cellulases, which revealed a conspicuous linear free energy relationship (LFER) between the substrate binding strength and the activation barrier. The scaling occurred despite the investigated enzymes being structurally and mechanistically diverse. We suggest that the scaling reflects basic physical restrictions of the hydrolytic process and that evolutionary selection has condensed cellulase phenotypes near the line. One consequence of the LFER is that the activity of a cellulase can be estimated from its substrate binding strength, irrespectively of structural and mechanistic details, and this appears promising for in silico selection and design within this industrially important group of enzymes.

Computing Cellulase Kinetics with a Two-Domain Linear Interaction Energy Approach.

While heterogeneous enzyme reactions play an essential role in both nature and green industries, computational predictions of their catalytic properties remain scarce. Recent experimental work demonstrated the applicability of the Sabatier principle for heterogeneous biocatalysis. This provides a simple relationship between binding strength and the catalytic rate and potentially opens a new way for inexpensive computational determination of kinetic parameters. However, broader implementation of this approach will require fast and reliable prediction of binding free energies of complex two-phase systems, and computational procedures for this are still elusive. Here, we propose a new framework for the assessment of the binding strengths of multidomain proteins, in general, and interfacial enzymes, in particular, based on an extended linear interaction energy (LIE) method. This two-domain LIE (2D-LIE) approach was successfully applied to predict binding and activation free energies of a diverse set of cellulases and resulted in robust models with high accuracy. Overall, our method provides a fast computational screening tool for cellulases that have not been experimentally characterized, and we posit that it may also be applicable to other heterogeneously acting biocatalysts.

Developing a CNT-SPE Sensing Platform Based on Green Synthesized AuNPs, Using Sargassum sp.

Detection and quantification of diverse analytes such as molecules, cells receptor and even particles and nanoparticles, play an important role in biomedical research, particularly in electrochemical sensing platform technologies. In this study, gold nanoparticles (AuNPs) prepared by green synthesis from Sargassum sp. were characterized using ultraviolet-visible (UV-Vis) and Fourier transform-infrared (FT-IR) spectroscopies, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and zeta potential (ζ) obtaining organic capped face-centered cubic 80-100 nm AuNPs with an excellent stability in a wide range of pH. The AuNPs were used to modify a carbon nanotubes-screen printed electrode (CNT-SPE), through the drop-casting method, to assemble a novel portable electrochemical sensing platform for glucose, using a novel combination of components, which together have not been employed. The ability to sense and measure glucose was demonstrated, and its electrochemical fundamentals was studied using cyclic voltammetry (CV). The limits of detection (LOD) and quantification (LOQ) to glucose were 50 µM and 98 µM, respectively, and these were compared to those of other sensing platforms.

Synthesis and Characterization of Inulin-Based Responsive Polyurethanes for Breast Cancer Applications.

In this study, new polyurethanes (PUs) were prepared by using inulin and polycaprolactone as polyols. Their structure and morphology were determined by Fourier transform infrared spectroscopy (FTIR), Raman dispersive spectroscopy, Nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), and scanning electron microscopy (SEM), whereas their mechanical properties were evaluated by a universal testing machine. Additionally, their water uptake, swelling behavior, and degradation were evaluated to be used as drug delivery carriers. Therefore, an anti-cancer drug was loaded to these PUs with 25% of loading efficiency and its release behavior was studied using different theoretical models to unveil its mechanism. Finally, the ability of the new PUs to be used as a clip marker in breast biopsy was evaluated. The results clearly demonstrate that these PUs are safe and can be used as intelligent drug release matrices for targeted drug delivery and exhibits positive results to be used for clip marker and in general for breast cancer applications.

Shock wave-assisted extraction of phenolic acids and flavonoids from Eysenhardtia polystachya heartwood: A novel method and its comparison with conventional methodologies.

Phenolic compounds, obtained from plants are important in the food, biomaterial and pharmaceutical industries; however current extraction methods, such as Soxhlet (solid-liquid) extraction, liquid-liquid extraction, microwave-assisted extraction, and ultrasonic extraction (USE), have the disadvantages of large processing times, contamination by solvents, and degradation of analytes. This study demonstrates that shock wave-assisted extraction can be used as a more efficient, eco-friendly and rapid method. Extraction of powdered samples of Eysenhardtia polystachia heartwood, a plant with high concentration of phenolic compounds, exposed to different doses of underwater shock waves, was compared with the conventional methods. Our results revealed that shock wave-assisted extraction (1500 shock waves with a peak positive pressure of approximately 88 MPa) produced 34.54% and 31.95% higher contents than Soxhlet and USE, respectively. Extraction times using shock waves were much shorter than with all other methods tested, proving that it is an attractive method to obtain both phenolic acids and flavonoids without the need for organic solvents. Furthermore, shock waves produced a significantly higher content of total reducing sugars than Soxhlet extraction and less phenolic acids which gives the insight of a more selective extraction of components.

Electrochemical Study of a Hybrid Polymethyl Methacrylate Coating using SiO2 Nanoparticles toward the Mitigation of the Corrosion in Marine Environments.

The demand for hydrophobic polymer-based protective coatings to impart high corrosion resistance has increased recently. The increase of the hydrophobicity in a hybrid coating is a new challenge, for that reason and in order to protect a metallic surface of oxidant agents, a poly (methyl methacrylate) (PMMA) coating with the addition of a different amount of silicon dioxide (SiO2) was developed. The hybrid coating was applied on a sample of stainless steel AISI 304 by the dip-coating method. The characterization of the coatings was determined by electrochemical impedance spectroscopy and with a scanning electrochemical microscopy. The best coatings were PMMA and PMMA + SiO2 0.01% that exhibits a real impedance in the Nyquist diagram of 760 and 427,800 MΩ⋅cm2, respectively, and the modulus of the real impedance in the Bode diagram present values of 2.2 × 108 and 3.3 × 108 Ω⋅cm2. Moreover, the phase angle presents constant values around 75° to 85° and 85° for the PMMA and PMMA + SiO2 0.01%, respectively. Moreover, the values of the real resistance for the PMMA + SiO2 0.01% coating present values in the order of Mega-ohms despite the coating exhibits an artificial defect in their surface. The contact angle test showed that the hydrophobicity of the hybrid PMMA + SiO2 0.01% coating is higher than that of the pure PMMA coatings. The hybrid PMMA + SiO2 coatings developed in this work are a very interesting and promising area of study in order to develop efficient products to protect metallic surfaces from corrosion phenomenon.

Fluorescence decay rate of selected compounds from Eysenhardtia polystachya extracts and their viability as biosensors.

Eysenhardtia polystachya (EP) is an endemic Mexican plant that has been widely studied for its antidiabetic, antibacterial, and antioxidant properties. Several studies had reported the main components of EP, but their fluorescence properties had not been broadly studied. In a previous study we obtained extracts with different composition from this plant and they presented florescence. In this work we study fluorescent compounds from EP and evaluate their fluorescence properties. EP extracts were obtained by Soxhlet extraction with ethanol, samples were dried, and compounds were separated by column chromatography. Fluorescent fractions were classified apart from other fractions and characterized by Scanning electron microscopy (SEM), UV-Vis, Raman, FTIR and 1H NMR spectra. Additionally, we obtained functional nanomaterials (using silica nanoparticles). TD-DFT molecular calculations of the fluorescent components were carried out to compare their theoretical UV-Vis spectra to experimental results. Nine fractions were obtained by chromatography and five of them showed fluorescence. Fluorescence of extracts from Eysenhardtia polystachya is due to more than one component and we suggest that could be other hydrochalcones for which we present possible structures. This finding would help to dissipate questions about which component is responsible for fluorescence in extracts from the plant and in this way determinate the appropriate use for these fluorophores. Finally, the application and viability as a biosensor using pulmonary epithelium fibroblast cell culture IMR-90 was proved, and in the concentration used are non-toxic materials.

Green synthesis of Ag nanoflowers using Kalanchoe Daigremontiana extract for enhanced photocatalytic and antibacterial activities.

The synthesis and applications of anisotropic nanostructures have attracted much attention in the last decade. The nanoflower-type structures are one of the nanomaterials with anisotropic structures most investigated because of owing to high densities of edges, corners, and stepped atoms present on their nano-petals. Here, silver nanoparticles obtained by a one-step green synthesis method using extract from Kalanchoe Daigremontiana´s leaves are reported. To identify the compounds responsible for reduction of silver ions, the functional groups present in plant extract were investigated by UV-vis and FTIR. Ag nanoparticles were characterized by UV-vis, XPS, ζ-potential, XRD, and SEM-EDS. Different solvents were used to eliminate agglomeration of the silver nanoparticles. These solvents produced nanoflower-like morphology with abundant nano-petals. This is the first report of the synthesis of Ag nanoflowers formed by green synthesis method using Kalanchoe Daigremontiana extract. The synthesized Ag nanoflowers are faced center cubic structure in nature with a petal thickness approximately of 25 nm. Photocatalytic activity of the different Ag nanostructures was evaluated through the degradation of methylene blue, where the degradation time as low as 1 min is reported. Furthermore these green synthesized Ag nanoflowers were found to show high antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-positive Staphylococcus aureus.

Stability Analysis of Anthocyanins Using Alcoholic Extracts from Black Carrot (Daucus Carota ssp. Sativus Var. Atrorubens Alef.).

Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to determine if microencapsulation with tetraethyl orthosilicate (TEOS) is a feasible option for preventing black carrot anthocyanin degradation. Extraction solvents were solutions of (1) ethanol/acetic acid and (2) ethanol/citric acid. Samples were purified through a resin column and microencapsulated using TEOS. Fourier Transformed Infrared Spectroscopy (FTIR) spectra of samples were obtained, and degradation studies were performed under different conditions of UV radiation, pH and temperature. Antioxidant activity was evaluated with radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and electrochemical cupric reducing antioxidant capacity (CUPRAC). Color evaluation on food models were performed with CIE Lab at the beginning of experiments and after 25 days of storage. Results indicate that the more stable extracts against pH media changes are samples obtained with ethanol/acetic acid solution as extraction solvent. Extract purification through resin and TEOS microencapsulation had no significant effect on extract stability. In conclusion, although TEOS microencapsulation has proven to be effective for some dried materials from natural extracts in our previous research, we do not recommend its use for black carrot extracts considering our results in this particular case.

Novel Biocompatible and Biodegradable PCL-PLA/ Iron Oxide NPs Marker Clip Composite for Breast Cancer Biopsy.

Strength and biocompatibility of composite materials (using a polymer matrix) are used in medicine for various devices such as prostheses and marker clips (biomarkers). Marker clips indicate the site of a lesion in the body, specifically for breast cancer diagnosis or treatment. In general, marker clips are made of steel or titanium, but lately, materials containing biodegradable polymers had been proposed. Our hypothesis is that a copolymer of polylactic acid and poly(ε-caprolactone) (PLA-PCL) could be used as marker clip material. After evaluating different polymer rates performance, metallic nanoparticles (NPs) were included to enhance the stability of the best copolymer and a marker clip prototype was proposed. Characterization of nanoparticles was made by dynamic light scattering (DLS), X-ray diffraction (XRD) and magnetic measurements. Mechanical, thermal and radiopacity properties were evaluated for composites formulation. In vitro, radiopaque experiments showed that BM-2 composite had the best performance. In vivo experiments showed that, after five months, the marker clip prototype maintained its shape, visibility and contrast properties. In consequence, a novel formulation of composite (PLA-PCL/metallic nanoparticles) is suitable for further studies as an alternative material for marker clips for breast cancer lesions.

Evaluation of Inulin Replacing Chitosan in a Polyurethane/Polysaccharide Material for Pb2+ Removal.

Downstream waste from industry and other industrial processes could increase concentration of heavy metals in water. These pollutants are commonly removed by adsorption because it is an effective and economical method. Previously, we reported adsorption capacity of a chitosan/polyurethane/titanium dioxide (TiO2) composite for three ions in a dynamic wastewater system. There, increasing the chitosan concentration in composite increased the cation removal as well; however, for ratios higher than 50% of chitosan/TiO2, the manufacturing cost increased significantly. In this work, we address the manufacturing cost problem by proposing a new formulation of the composite. Our hypothesis is that inulin could replace chitosan in the composite formulation, either wholly or in part. In this exploratory research, three blends were prepared with a polyurethane matrix using inulin or/and chitosan. Adsorption was evaluated using a colorimetric method and the Langmuir and Freundlich models. Fourier-transform infrared spectroscopy (FTIR) spectra, scanning electron microscopy (SEM) micrographs, differential scanning calorimetry and thermogravimetric analysis curves were obtained to characterize blends. Results indicate that blends are suitable for toxic materials removal (specifically lead II, Pb2+). Material characterization indicates that polysaccharides were distributed in polyurethane's external part, thus improving adsorption. Thermal degradation of materials was found above 200 °C. Comparing the blends data, inulin could replace chitosan in part and thereby improve the cost efficiency and scalability of the production process of the polyurethane based-adsorbent. Further research with different inulin/chitosan ratios in the adsorbent and experiments with a dynamic system are justified.

Effects of tetraethyl orthosilicate (TEOS) on the light and temperature stability of a pigment from Beta vulgaris and its potential food industry applications.

A novel, simple and inexpensive modification method using TEOS to increase the UV light, pH and temperature stability of a red-beet-pigment extracted from Beta vulgaris has been proposed. The effects on the molecular structure of betalains were studied by FTIR spectroscopy. The presence of betacyanin was verified by UV-Vis spectroscopy and its degradation in modified red-beet-pigment was evaluated and compared to the unmodified red-beet-pigment; performance improvements of 88.33%, 16.84% and 20.90% for UV light, pH and temperature stability were obtained, respectively,. Measurements of reducing sugars, phenol, and antioxidant contents were performed on unmodified and modified red-beet-pigment and losses of close to 21%, 54% and 36%, respectively, were found to be caused by the addition of TEOS. Polar diagrams of color by unmodified and modified red-beet-pigment in models of a beverage and of a yogurt were obtained and the color is preserved, although here is a small loss in the chromaticity parameter of the modified red-beet-pigment.