Chitosan alchemy: transforming tissue engineering and wound healing.

Chitosan, a biopolymer acquired from chitin, has emerged as a versatile and favorable material in the domain of tissue engineering and wound healing. Its biocompatibility, biodegradability, and antimicrobial characteristics make it a suitable candidate for these applications. In tissue engineering, chitosan-based formulations have garnered substantial attention as they have the ability to mimic the extracellular matrix, furnishing an optimal microenvironment for cell adhesion, proliferation, and differentiation. In the realm of wound healing, chitosan-based dressings have revealed exceptional characteristics. They maintain a moist wound environment, expedite wound closure, and prevent infections. These formulations provide controlled release mechanisms, assuring sustained delivery of bioactive molecules to the wound area. Chitosan's immunomodulatory properties have also been investigated to govern the inflammatory reaction during wound healing, fostering a balanced healing procedure. In summary, recent progress in chitosan-based formulations portrays a substantial stride in tissue engineering and wound healing. These innovative approaches hold great promise for enhancing patient outcomes, diminishing healing times, and minimizing complications in clinical settings. Continued research and development in this field are anticipated to lead to even more sophisticated chitosan-based formulations for tissue repair and wound management. The integration of chitosan with emergent technologies emphasizes its potential as a cornerstone in the future of regenerative medicine and wound care. Initially, this review provides an outline of sources and unique properties of chitosan, followed by recent signs of progress in chitosan-based formulations for tissue engineering and wound healing, underscoring their potential and innovative strategies.

Hydrogeochemical characteristics and air quality risks associated with gold mining operations in Egypt using geochemical modeling and risk indices.

The success of industrial operations depends on the effective identification, appraisal, and mitigation of possible hazards and associated environmental concerns. This report provides a complete review of environmental management techniques at the Sukari Gold Mine (SGM), located in the southeastern desert of Egypt. Extensive environmental measurements were taken to assess air and water quality, identify hazards, and analyze risks on the SGM premises. Air quality and noise intensity levels were measured at 39 places around the mine's working region. The findings found noncompliance with the Egyptian Environmental Law's (EEL4/94) noise exposure limitations, with the Power Generator House having the maximum noise levels at 107 dB. Remedial measures such as personal protective equipment (PPE) and exposure limit reduction strategies are being considered to address elevated noise levels. Measurements of particulate matter (PM10) and noxious gases (e.g., CO, SO2, NO2, HCN, and NH3) were conducted in workplace and ambient environments. Elevated PM10 concentrations were particularly concerning in underground regions, forcing the deployment of water depression techniques and improved PPE measures. While gas emissions from most activities remained under regulatory limits, select zones showed hydrogen cyanide (HCN) levels that exceeded permitted thresholds, necessitating specific control actions. Using hazard index (HI) and risk rating assessments, this study found different risk profiles across SGM's workplaces, focusing on high-risk regions for focused intervention. Additionally, a water assessment near a Tailing Storage Facility (TSF) was conducted to monitor the impact of mining activities on groundwater quality. The study revealed that groundwater in the region belongs to the Na-K-Cl-SO4 and Ca-Mg-Cl-SO4 water classes, with potential degradation attributed to high mineralization processes induced by aquifer materials and seawater intrusion. The findings underscore the importance of ongoing monitoring, control measures, and implementation of programs to ensure environmental sustainability and minimize risks associated with mining activities in the Sukari Gold Mines. This research highlights the imperative of continuous monitoring, proactive control measures, and the implementation of environmental initiatives to ensure the sustainability of mining operations within the Sukari Gold Mines.

Studies of Fractal Microstructure in Nanocarbon Polymer Composites.

The in situ study of fractal microstructure in nanocarbon polymers is an actual task for their application and for the improvement in their functional properties. This article presents a visualization of the bulk structural features of the composites using pulsed acoustic microscopy and synchrotron X-ray microtomography. This article presents details of fractal structure formation using carbon particles of different sizes and shapes-exfoliated graphite, carbon platelets and nanotubes. Individual structural elements of the composite, i.e., conglomerations of the particles in the air capsule as well as their distribution in the composite volume, were observed at the micro- and nanoscale. We have considered the influence of particle architecture on the fractal formation and elastic properties of the composite. Acoustic and X-ray imaging results were compared to validate the carbon agglomeration.

Microwave engineered NiZrO3@GNP as efficient electrode material for energy storage applications.

Supercapacitors (SCs) have emerged as attractive energy storage devices due to their rapid charge/discharge rates, long cycle life, and high-power density. However, the development of innovative electrode materials to achieve high-performance remains crucial to meet future requirements in supercapacitor technology. In this work, we have explored the potential of a microwave-engineered NiZrO3@GNP composite as a promising electrode material for SCs. A microwave assisted hydrothermal approach was adopted for the fabrication of the NiZrO3@GNP nanocomposite. Structural and morphological investigations showed its structural richness and its chemical compositions. When applied as a SC electrode, this innovative combination exhibits battery-like behaviour with higher specific capacity (577.63 C g-1) with good cyclic stability, and good performance. We have assembled an asymmetric-type two-electrode SC device and analysed its electrochemical features. This NiZrO3@GNP device exhibits the specific capacity of 47 C g-1 with capacitance retention of 70% after 2000 charge-discharge cycles. Further research on optimizing the synthesis process and exploring different device configurations could pave the way for even higher-performance supercapacitors in the future.

Surface Modification Strategies for Chrysin-Loaded Iron Oxide Nanoparticles to Boost Their Anti-Tumor Efficacy in Human Colon Carcinoma Cells.

Enhancing nanoparticles' anti-cancer capabilities as drug carriers requires the careful adjustment of formulation parameters, including loading efficiency, drug/carrier ratio, and synthesis method. Small adjustments to these parameters can significantly influence the drug-loading efficiency of nanoparticles. Our study explored how chitosan and polyethylene glycol (PEG) coatings affect the structural properties, drug-loading efficiency, and anti-cancer efficacy of Fe3O4 nanoparticles (NPs). The loading efficiency of the NPs was determined using FTIR spectrometry and XRD. The quantity of chrysin incorporated into the coated NPs was examined using UV-Vis spectrometry. The effect of the NPs on cell viability and apoptosis was determined by employing the HCT 116 human colon carcinoma cell line. We showed that a two-fold increase in drug concentration did not impact the loading efficiency of Fe3O4 NPs coated with PEG. However, there was a 33 Å difference in the crystallite sizes obtained from chitosan-coated Fe3O4 NPs and drug concentrations of 1:0.5 and 1:2, resulting in decreased system stability. In conclusion, PEG coating exhibited a higher loading efficiency of Fe3O4 NPs compared to chitosan, resulting in enhanced anti-tumor effects. Furthermore, variations in the loaded amount of chrysin did not impact the crystallinity of PEG-coated NPs, emphasizing the stability and regularity of the system.

From algae to advancements: laminarin in biomedicine.

Laminarin, a complicated polysaccharide originating from brown algae, has emerged as a compelling candidate in the domain of biomedical research. This enigmatic molecule, composed of glucose units associated with both ß-1,3 and ß-1,6 glycosidic bonds, possesses an array of remarkable characteristics that render it auspicious for multifaceted biomedical applications. This review investigates the comprehensive potential of laminarin in the biomedical domain, emphasizing its remarkable biocompatibility, low cytotoxicity, and cell proliferation support. Laminarin's immunomodulatory attributes position it as an encouraging contender in immunotherapy and the development of vaccines. Moreover, its anti-inflammatory and antioxidant characteristics provide a promising avenue for combatting conditions associated with oxidative stress. In particular, laminarin excels as a drug delivery vehicle owing to its exceptional encapsulation capabilities emerging from its porous framework. Integrating pH and redox responsiveness in laminarin-based drug delivery systems is poised to redefine targeted therapies. Laminarin substantially contributes to tissue engineering by improving adhesion, migration of cells, and deposition of extracellular matrix. This augmentation magnifies the regenerative capability of tissue-engineered constructs, substantiated by the advancement of laminarin-based wound dressings and tissue scaffolds, marking considerable progress in the domain of wound healing and tissue regeneration. While laminarin exhibits substantial potential in biomedical applications, it remains in the initial phases of exploration. Comprehensive preclinical and clinical research is warranted to verify its effectiveness and safety across various applications. In essence, laminarin, a marine marvel, has the capability to remodel biomedical research, offering inventive solutions to complex difficulties.

Solid Lipid Nanoparticles Containing Dopamine and Grape Seed Extract: Freeze-Drying with Cryoprotection as a Formulation Strategy to Achieve Nasal Powders.

(1) Background: DA-Gelucire® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson's disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-ß-cyclodextrin (Me-ß-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-ß-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-ß-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-ß-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.

Enhanced Stability of Dopamine Delivery via Hydrogel with Integrated Graphene.

The synthesis of graphene-based materials for drug delivery represents an area of active research, and the use of graphene in drug delivery systems is promising due to its unique properties. Thus, in the present work, we discuss the potential of few-layer graphene in a hydrogel system for dopamine release. The hydrogels are frequently used for these systems for their special physico-chemical properties, which can ensure that the drug is effectively released in time. However, the release from such structures is mostly determined by diffusion alone, and to overcome this restriction, the hydrogel can be "improved" with nanoscale fillers like graphene. The release kinetics of the composite obtained were analyzed to better understand how the use of graphene, instead of the more common graphene oxide (GO) and reduced graphene oxide (rGO), affects the characteristics of the system. Thus, the systems developed in this study consist of three main components: biopolymer, graphene, and dopamine. The hydrogels with graphene were prepared by combining two different solutions, one with polyacrylic acid and agarose and one with graphene prepared by the exfoliation method with microwave irradiation. The drug delivery systems were developed by adding dopamine to the obtained hydrogels. After 24 h of release, the presence of dopamine was observed, demonstrating that the system developed can slow down the drug's degradation because of the interactions with the graphene nanoplates and the polymer matrix.

Tunable optical and semiconducting properties of eco-friendly-prepared reduced graphene oxide.

Wide bandgap oxidized graphenes have garnered particular interest among the materials explored for these applications because of their exceptional semiconducting and optical properties. This study aims to investigate the tunability of the related properties in reduced graphene oxide (rGO) for potential use in energy conversion, storage, and optoelectronic devices. To accomplish this, we scrutinized crucial parameters of the synthesis process such as reduction time and temperature. Our findings demonstrate that controlling these parameters makes it possible to customize the optical bandgap of reduced graphene oxide within a range of roughly 2.2 eV-1.6 eV. Additionally, we observed that reduced graphene oxide has strong and superior absorption in the visible region, which is attributable to the existence of OFGs and defects. Notably, our results indicate that the absorption coefficients of reduced graphene oxide are up to almost three times higher (7426 ml mg-1 m-1) than those observed in dispersions of exfoliated graphene and graphene oxide (GO). To complement our findings, we employed several spectroscopic and morphological characterizations, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and electrical measurements. The implications of our results are significant for the development and design of future semiconductors for energy conversion and optoelectronic applications.

Optical properties of graphene oxide.

The study of the optical properties of graphene oxide (GO) is crucial in designing functionalized GO materials with specific optical properties for various applications such as (bio) sensors, optoelectronics, and energy storage. The present work aims to investigate the electronic transitions, optical bandgap, and absorption coefficient of GO under different conditions. Specifically, the study examines the effects of drying times ranging from 0 to 120 h while maintaining a fixed temperature of 80°C and low temperatures ranging from 40℃ to 100℃, with a constant drying time of 24 h. Our findings indicate that exposing the GO sample to a drying time of up to 120 h at 80°C can lead to a reduction in the optical bandgap, decreasing it from 4.09 to 2.76 eV. The π-π* transition was found to be the most affected, shifting from approximately 230 nm at 0 h to 244 nm after 120 h of drying time. Absorption coefficients of 3140-5507 ml mg-1 m-1 were measured, which are similar to those reported for exfoliated graphene dispersions but up to two times higher, confirming the improved optical properties of GO. Our findings can provide insights into determining the optimal temperature and duration required for transforming GO into its reduced form for a specific application through extrapolation. The study is complemented by analyzing the elemental composition, surface morphology change, and electrical properties.

Nonlinear Optical Properties of Zn(II) Porphyrin, Graphene Nanoplates, and Ferrocene Hybrid Materials.

Following some previous work by some of us on the second order nonlinear optical (NLO) properties of Zn(II) meso-tetraphenylporphyrin (ZnP), fullerene, and ferrocene (Fc) diads and triads, in the present research, we explore the NLO response of some new hybrids with two-dimensional graphene nanoplates (GNP) instead of a zero-dimensional fullerene moiety as the acceptor unit. The experimental data, collected by Electric Field Induced Second Harmonic generation (EFISH) technique in CH2Cl2 solution with a 1907 nm incident wavelength, combined with Coupled-Perturbed (CP) and Finite Field (FF) Density Functional Theory (DFT) calculations, show a strongly enhanced contribution of the cubic electronic term γ(-2ω; ω, ω, 0), due to the extended π-conjugation of the carbonaceous acceptor moiety.

Temperature-Dependent Optical Properties of Oxidized Graphenes.

In this study, we investigate how changing important synthesis-related parameters can affect and control the optical characteristics of graphene oxide (GO) and reduced graphene oxide (rGO). These parameters include drying time and reduction time at two different temperatures. We obtain an understanding of their impact on optical transitions, optical bandgap, absorption coefficient, and absorbance spectrum width by analyzing these factors. Accordingly, GO has an optical bandgap of about 4 eV, which is decreased by the reduction process to 1.9 eV. Both GO and rGO display greater absorption in the visible spectrum, which improves photon capture and boosts efficiency in energy conversion applications. Additionally, our results show that GO and rGO have higher absorption coefficients than those previously reported for dispersions of exfoliated graphene. Defects in GO and rGO, as well as the presence of functional oxygen groups, are the main contributors to this increased absorption. Several measurements are carried out, including spectroscopic and morphological studies, to further support our findings.

Synthesis and Characterization of Methoxy-Exfoliated Montmorillonite Nanosheets as Potential Carriers of 5-Fluorouracil Drug with Enhanced Loading, Release, and Cytotoxicity Properties.

Natural bentonite clay (BE) underwent modification steps that involved the exfoliation of its layers into separated nanosheets (EXBE) and further functionalization of these sheets with methanol, forming methoxy-exfoliated bentonite (Mth/EXBE). The synthetically modified products were investigated as enhanced carriers of 5-fluorouracil as compared to raw bentonite. The modification process strongly induced loading properties that increased to 214.4 mg/g (EXBE) and 282.6 mg/g (Mth/EXBE) instead of 124.9 mg/g for bentonite. The loading behaviors were illustrated based on the kinetic (pseudo-first-order model), classic isotherm (Langmuir model), and advanced isotherm modeling (monolayer model of one energy). The Mth/EBE carrier displays significantly higher loading site density (95.9 mg/g) as compared to EXBE (66.2 mg/g) and BE (44.9 mg/g). The loading numbers of 5-Fu in each site of BE, EXBE, and Mth/EXBE (>1) reflect the vertical orientation of these loaded ions involving multi-molecular processes. The loading processes that occurred appeared to be controlled by complex physical and weak chemical mechanisms, considering both Gaussian energy (<8 KJ/mol) as well as loading energy (<40 KJ/mol). The releasing patterns of EXBE and Mth/EXBE exhibit prolonged and continuous properties up to 100 h, with Mth/EXBE displaying much faster behaviors. Based on the release kinetic modeling, the release reactions exhibit non-Fickian transport release properties, validating cooperative diffusion and erosion release mechanisms. The cytotoxicity of 5-Fu is also significantly enhanced by these carriers: 5-Fu/BE (8.6% cell viability), 5-Fu/EXBE (2.21% cell viability), and 5-Fu/Mth/EXBE (0.73% cell viability).

Seasonal and spatial contamination of trace elements in sediments and fish tissues (Mugil Chephalus) from Annaba gulf (North East of Algeria).

This research is devoted to assessing the pollution within a Mediterranean Sea area in the East coast of Algeria, which is known for its port and industrial activities. This study aims to assess the health status of the Gulf of Annaba located in the extreme North-East of Algeria by examining the contamination level by trace elements (Cu, Zn, Pb, Cd, Hg) in the sediments and muscles of Mugil cephalus fish. The obtained results manifest significant variations in metal levels in the sediments throughout the stations and the sampling seasons. The contamination by (Zn, Cu, Pb, Cd) of Joannonville and Sidi Salem stations is observed during both seasons whereas at the Chapuis station occurs only during the summer. The contamination indices are higher than 3, hence classifying the sediments of these three stations as "sediments at risk". Joannonville station manifests high levels of Hg only during the summer. For the muscles of M. cephalus, the contamination levels are found to be dependent on the species and the studied station. The fish inhabiting Joannonville and Sidi Salem show higher levels of (Zn, Pb, Cd) compared to the FAO/WHO standards, whereas the Pb level at Chapuis exceeds the standard during summer. Accordingly, the consumption of fish from Joannonville, Sidi Salem and Chapuis stations presents a serious threat regarding the toxicological risks based on the observed levels of contamination.

Synthesis and Characterization of ß-Cyclodextrin-Hybridized Exfoliated Kaolinite Single Nanosheets as Potential Carriers of Oxaliplatin with Enhanced Loading, Release, and Cytotoxic Properties.

Natural kaolinite was subjected to a successful exfoliation process into separated kaolinite nanosheets (KNs), followed by hybridization with ß-cyclodextrin biopolymer (ß-CD), forming an advanced bio-nanocomposite (ß-CD/KNs). The synthetic products were evaluated as enhanced delivery structures for oxaliplatin chemotherapy (OXAPN). The hybridization of KNs with ß-CD polymer notably enhanced the loading capacity to 355.3 mg/g (ß-CD/KNs) as compared to 304.9 mg/g for KNs. The loading of OXAPN into both KNs and ß-CD/KNs displayed traditional pseudo-first-order kinetics (R2 > 0.85) and a conventional Langmuir isotherm (R2 = 0.99). The synthetic ß-CD/KNs validates a greater occupied effective site density (98.7 mg/g) than KNs (66.3 mg/g). Furthermore, the values of the n steric parameter (4.7 (KNs) and 3.6 (ß-CD/KNs)) reveal the vertical orientation of the loaded molecules and the loading of them by multi-molecular mechanisms. These mechanisms are mainly physical processes based on the obtained Gaussian energy (<8 KJ/mol) and loading energy (<40 KJ/mol). The release profiles of both KNs and ß-CD/KNs extend for about 120 h, with remarkably faster rates for ß-CD/KNs. According to the release kinetic findings, the release of OXAPN displays non-Fickian transport behavior involving the cooperation of diffusion and erosion mechanisms. The KNs and ß-CD/KNs as free particles showed considerable cytotoxicity and anticancer properties against HCT-116 cancer cell lines (71.4% cell viability (KNs) and 58.83% cell viability (ß-CD/KNs)). Additionally, both KNs and ß-CD/KNs significantly enhanced the OXAPN's cytotoxicity (2.04% cell viability (OXAPN/KNs) and 0.86% cell viability (OXAPN/ß-CD/KNs).

Insights into the Effect of Chitosan and ß-Cyclodextrin Hybridization of Zeolite-A on Its Physicochemical and Cytotoxic Properties as a Bio-Carrier for 5-Fluorouracil: Equilibrium and Release Kinetics Studies.

Synthetic zeolite-A (ZA) was hybridized with two different biopolymers (chitosan and ß-cyclodextrin) producing biocompatible chitosan/zeolite-A (CS/ZA) and ß-cyclodextrin/zeolite-A (CD/ZA) biocomposites. The synthetic composites were assessed as bio-carriers of the 5-fluorouracil drug (5-Fu) with enhanced properties, highlighting the impact of the polymer type. The hybridization by the two biopolymers resulted in notable increases in the 5-Fu loading capacities, to 218.2 mg/g (CS/ZA) and 291.3 mg/g (CD/ZA), as compared to ZA (134.2 mg/g). The loading behaviors using ZA as well as CS/ZA and CD/ZA were illustrated based on the classic kinetics properties of pseudo-first-order kinetics (R2 > 0.95) and the traditional Langmuir isotherm (R2 = 0.99). CD/ZA shows a significantly higher active site density (102.7 mg/g) in comparison to CS/ZA (64 mg/g) and ZA (35.8 mg/g). The number of loaded 5-Fu per site of ZA, CS/ZA, and CD/ZA (>1) validates the vertical ordering of the loaded drug ions by multi-molecular processes. These processes are mainly physical mechanisms based on the determined Gaussian energy (<8 kJ/mol) and loading energy (<40 kJ/mol). Both the CS/ZA and CD/ZA 5-Fu release activities display continuous and controlled profiles up to 80 h, with CD/ZA exhibiting much faster release. According to the release kinetics studies, the release processes contain non-Fickian transport release properties, suggesting cooperative diffusion and erosion release mechanisms. The cytotoxicity of 5-Fu is also significantly enhanced by these carriers: 5-Fu/ZA (11.72% cell viability), 5-Fu/CS/ZA (5.43% cell viability), and 5-Fu/CD/ZA (1.83% cell viability).

Insight into the Morphological Properties of Nano-Kaolinite (Nanoscrolls and Nanosheets) on Its Qualification as Delivery Structure of Oxaliplatin: Loading, Release, and Kinetic Studies.

Natural kaolinite underwent advanced morphological-modification processes that involved exfoliation of its layers into separated single nanosheets (KNs) and scrolled nanoparticles as nanotubes (KNTs). Synthetic nanostructures have been characterized as advanced and effective oxaliplatin-medication (OXAP) delivery systems. The morphological-transformation processes resulted in a remarkable enhancement in the loading capacity to 304.9 mg/g (KNs) and 473 mg/g (KNTs) instead of 29.6 mg/g for raw kaolinite. The loading reactions that occurred by KNs and KNTs displayed classic pseudo-first-order kinetics (R2 > 0.90) and conventional Langmuir isotherms (R2 = 0.99). KNTs exhibit a higher active site density (80.8 mg/g) in comparison to KNs (66.3 mg/g) and raw kaolinite (6.5 mg/g). Furthermore, compared to KNs and raw kaolinite, each site on the surface of KNTs may hold up to six molecules of OXAP (n = 5.8), in comparison with five molecules for KNs. This was accomplished by multi-molecular processes, including physical mechanisms considering both the Gaussian energy (<8 KJ/mol) and the loading energy (<40 KJ/mol). The release activity of OXAP from KNs and KNTs exhibits continuous and regulated profiles up to 100 h, either by KNs or KNTs, with substantially faster characteristics for KNTs. Based on the release kinetic investigations, the release processes have non-Fickian transport-release features, indicating cooperative-diffusion and erosion-release mechanisms. The synthesized structures have a significant cytotoxicity impact on HCT-116 cancer cell lines (KNs (71.4% cell viability and 143.6 g/mL IC-50); KNTs (11.3% cell viability and 114.3 g/mL IC-50). Additionally, these carriers dramatically increase OXAP's cytotoxicity (2.04% cell viability, 15.4 g/mL IC-50 (OXAP/KNs); 0.6% cell viability, 4.5 g/mL IC-50 (OXAP/KNTs)).

Biological Activities of Sargassum Algae Mediated ZnO and Co Doped ZnO Nanoparticles as Enhanced Antioxidant and Anti-Diabetic Agents.

Brown macroalgae (BMG) were used as carriers for ZnO (ZnO/BMG) and cobalt-doped ZnO (Co-ZnO/BMG) via facile microwave-assisted hydrothermal synthesis. The multifunctional structures of synthesized composites were evaluated as enhanced antioxidant and anti-diabetic agents based on the synergistic effects of ZnO, Co-ZnO, and BMG. BMG substrate incorporation and cobalt doping notably enhanced the bioactivity of the synthesized ZnO nanoparticles. As an antioxidant, the Co-ZnO/BMG composite exhibited highly effective scavenging properties for the common free reactive oxygen radicals (DPPH [89.6 ± 1.5%], nitric oxide [90.2 ± 1.3%], ABTS [87.7 ± 1.8%], and O2●- [46.7 ± 1.9%]) as compared to ascorbic acid. Additionally, its anti-diabetic activity was enhanced significantly and strongly inhibited essential oxidative enzymes (porcine α-amylase (90.6 ± 1.5%), crude α-amylase (84.3 ± 1.8%), pancreatic α-glucosidase (95.7 ± 1.4%), crude intestinal α-glucosidase (93.4 ± 1.8%), and amyloglucosidase (96.2 ± 1.4%)). Co-ZnO/BMG inhibitory activity was higher than that of miglitol, and in some cases, higher than or close to that of acarbose. Therefore, the synthetic Co-ZnO/BMG composite can be used as a commercial anti-diabetic and antioxidant agent, considering the cost and adverse side effects of current drugs. The results also demonstrate the impact of cobalt doping and BMG integration on the biological activity of ZnO.

Femtosecond laser-induced nano- and microstructuring of Cu electrodes for CO2 electroreduction in acetonitrile medium.

The dependency of CO2 reduction rate in acetonitrile-Bu4NClO4 solution on cathodes, which were modified by laser induction of a copper surface, was studied. The topography of laser-induced periodic surface structures (LIPSS) → grooves → spikes was successively formed by a certain number of pulses. It was proved that for a higher number of laser pulses, the surface area of the copper cathode increases and preferred platy orientation of the copper surface on [022] crystallografic direction and larger fluence values increase. At the same time, the content of copper (I) oxide on the surface of the copper cathode increases. Also, the tendency to larger fluency values is observed. It promotes the increase of cathodic current density for CO2 reduction, which reaches values of 14 mA cm-2 for samples with spikes surface structures at E = - 3.0 V upon a stable process.

Synthesis and Biological Activity Evaluations of Green ZnO-Decorated Acid-Activated Bentonite-Mediated Curcumin Extract (ZnO@CU/BE) as Antioxidant and Antidiabetic Agents.

Green ZnO-decorated acid-activated bentonite-mediated curcumin extract (ZnO@CU/BE) was prepared as a multifunctional antioxidant and antidiabetic agent based on the extract of curcumin, which was used as a reducing and capping reagent. ZnO@CU/BE showed notably enhanced antioxidant properties against nitric oxide (88.6 ± 1.58%), 1,1-diphenyl-2-picrylhydrazil (90.2 ± 1.76%), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (87.3 ± 1.61%), and superoxide (39.5 ± 1.12%) radicals. These percentages are higher than the reported values of ascorbic acid as a standard and the integrated components of the structure (CU, BE/CU, and ZnO). This signifies the impact of the bentonite substrate on enhancing the solubility, stability, dispersion, and release rate of the intercalated curcumin-based phytochemicals, in addition to enhancing the exposure interface of ZnO nanoparticles. Therefore, effective antidiabetic properties were observed, with significant inhibition effects on porcine pancreatic α-amylase (76.8 ± 1.87%), murine pancreatic α-amylase (56.5 ± 1.67%), pancreatic α-glucosidase (96.5 ± 1.07%), murine intestinal α-glucosidase (92.5 ± 1.10%), and amyloglucosidase (93.7 ± 1.55%) enzymes. These values are higher than those determined using commercial miglitol and are close to the values measured using acarbose. Hence, the structure can be applied as an antioxidant and antidiabetic agent.