Biosynthesis of silver and gold nanoparticles using Sargassum horneri extract as catalyst for industrial dye degradation

This study focuses on the green synthesis of silver and gold nanoparticles using the marine algae extract, Sargassum horneri, as well as the degradation of organic dyes using biosynthesized nanoparticles as catalysts. The phytochemicals of the brown algae Sargassum horneri acted as reducing and capping agents for nanoparticle synthesis. Ultraviolet–visible absorption spectroscopy, dynamic light scattering, high-resolution transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy were used to characterize the biosynthesized nanoparticles. The green-synthesized SH-AgNPs and SH-AuNPs exhibited high catalytic activity for degradation of organic dyes, such as methylene blue, rhodamine B, and methyl orange. The reduction reactions of dyes are based on pseudo-first-order kinetics.     

Progress on phthalocyanine-conjugated Ag and Au nanoparticles: Synthesis,characterization, and photo-physicochemical properties

Phthalocyanine (Pc) complexes are an important class of dyes with numerous (e.g., biological, photophysical, and analytical) applications. Among the methods used to improve the properties of these complexes, one should mention the introduction of different substituents, variation of the central metal ion, ligand exchange, and conjugation to nanomaterials (e.g., carbon-based nanomaterials and metal nanoparticles (NPs)). This work briefly reviews Pc complex conjugation to Ag and Au NPs, highlights the different NP shapes, and discusses the diversity of conjugation approaches. Moreover, the use of UV–Vis spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering and Fourier transform infrared spectroscopy to characterize Pc-NP hybrids is summarized. The effect of conjugation on Pc photo-physicochemical properties (fluorescence, singlet oxygen generation, triplet state formation, and optical limiting behavior) is discussed, and future perspectives for the synthesis and applications of new hybrids are provided.     

Eco-friendly synthesis of size-controlled silver nanoparticles by using Areca catechu nut aqueous extract and investigation of their potent antioxidant and anti-bacterial activities

Silver nanoparticles (AgNPs) have attracted considerable attention owing to their unique biological applications. AgNPs synthesized by plant extract is considered as a convenient, efficient and eco-friendly material. In this work, the aqueous extract of Areca catechu L. nut (ACN) was used as the reducing and capping agents for one-pot synthesis of AgNPs, and their antioxidant and antibacterial activities were investigated. UV (Ultra Violet)-visible spectrum and dynamic light scattering (DLS) analysis revealed that the size of AgNPs was sensitive to the synthesis conditions. The synthesized AgNPs were composed of well-dispersed particles with an small size of about 10 nm under the optimal conditions (pH value of extract was 12.0; AgNO₃ concentration was 1.0 mM; reaction time was 90 min). In addition, scanning electron microscope with energy dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM) and X-ray diffraction (XRD) results further verified that the synthesized AgNPs had a stable and well-dispersed form (Zeta potential value of ?30.50 mV and polydispersity index of 0.328) and a regular spherical shape (average size of 15–20 nm). In addition, Fourier transform infrared spectrometry (FTIR) results revealed that phytochemical constituents in ACN aqueous extract accounted for Ag⁺ ion reduction, capping and stabilization of AgNPs. The possible reductants in the aqueous extract of Areca catechu L. nut were identified by high-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (HPLC-ESI-qTOF/MS) method. More importantly, the synthesized AgNPs indicated excellent free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH, IC₅₀ = 11.75 ± 0.29 μg/mL) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS⁺, IC₅₀ = 44.85 ± 0.37 μg/mL), which were significant higher than that of ascorbic acid. Moreover, AgNPs exhibited an enhanced antibacterial activity against six selected common pathogens (especially Escherichia coli and Staphylococcus aureus) compared with AgNO₃ solution. In a short, this study showed that the Areca catechu L. nut aqueous extract could be applied for eco-friendly synthesis of AgNPs.     

Incorporations of gold,silver and carbon nanomaterials to kombucha-derived bacterial cellulose: Development of antibacterial leather-like materials

Bacterial cellulose (BC), derived from kombucha scoby have extraordinary organoleptic properties suitable for development of leather-like materials. An improvement in physical and mechanical property is desirable for the practical applications. This work deals with the treatment of BC by incorporations of three different nanomaterials such as gold nanoparticles (AuNP), silver nanoparticles (AgNP) and graphene oxide (GO). Achieving combined benefits via synergic interactions of different nanomaterials is the major objective herein. While graphene oxide can influence some of the parameters related to mechanical properties, silver nanomaterials can offer antibacterial characteristics. Gold nano materials can bridge the BC/silver/graphene oxide as well as provide the desirable aesthetic colour. Different physical chemical and mechanical characteristics were studied in detail. For example, changes in morphology by imaging fiber network were studied using scanning electron microscopy. Fibre properties were studied by Small Angle X-Ray Scattering (SAXS) and X-Ray Diffraction (XRD). Elemental composition was studied by X-ray photoelectron spectroscopy (XPS) analysis and Raman analysis. The improvement of hydrophobicity was studied by Contact angle meter. Thermal analysis was performed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). A Picture was provided in ESI to show the modified material's leather-like appearances.     

Ratiometric electrochemical,electrochemiluminescent, and photoelectrochemical strategies for environmental contaminant detection

Global environmental pollution issue has boosted the development of novel analytical techniques with high efficiency and accuracy for detection of hazardous contaminants. Strategies based on electrochemical, electrochemiluminescent, or photoelectrochemical analysis are among the promising detection approaches to provide rapid and sensitive analysis. Currently, combining ratiometric assay with such strategies can further promote their sensing reliability and reproducibility in complex conditions. This review highlights recent advances of ratiometric electrochemical, electrochemiluminescent, and photoelectrochemical sensors in the past 2 years. Their signal generation strategies and analysis applications, particularly for the environmental contaminant detection, are discussed in detail, and a future prospect in this area from us is also provided.     

Assessment of antioxidant and cytotoxic potential of silver nanoparticles synthesized from root extract of Reynoutria japonica Houtt

Free radicals, mostly consist of reactive oxygen species, are generated in human body by several exogenous and endogenous systems. Overproduction of free radicals is known to cause several degenerative disorders including cancer. The aim of this study is to synthesize silver nanoparticles (AgNPs) using root extract of Reynoutria japonica and to investigate its antioxidant and cytotoxic potential. AgNPs were synthesized by green approach and subsequently characterized using UV–vis spectroscopy, SEM, TEM, FTIR, XRD, EDS and DLS. The antioxidant activity was investigated using DPPH, FRAP, H₂O₂, and ABT?⁺ radical scavenging assays while the cytotoxic effect was assessed using different human cancer cell lines including lung (A549), liver (Hep-G2) and breast (MDA-MB-231) by MTS assay. Moreover, the specificity of NPs was assessed against two normal human cell lines e.g. alveolar and renal primary epithelial cells (HPAEpiC and HRPTEpiC). The UV–vis spectra confirmed the synthesis of AgNPs by producing a characteristic peak at 410 nm. Further analysis confirmed that AgNPs were crystalline in nature, predominantly spherical in shape, with an average width and area of 17.34 nm and 164.46 nm², respectively. DLS analysis revealed that NPs possess a high negative zeta potential value (?28.5 mV), thus facilitating its electrostatic stabilization. AgNPs showed dose dependent antioxidant activity against DPPH, FRAP, H₂O₂ and ABTS with IC₅₀ values 19.25, 22.45, 24.20 and 18.88 µg/ml, respectively. The AgNPs depicted significant cytotoxic effects against A549, Hep-G2 and MDA-MB-231 cell lines with IC₅₀ values of 4.5, 5.1 and 3.46 µg/ml, respectively. Moreover, the NPs exhibited highest selectivity index (>2.0) for A549, Hep-G2 and MDA-MB-231, confirming its specificity towards cancer cell lines. In conclusion, AgNPs prepared from root extract of R. japonica possess strong antioxidant and cytotoxic potential which suggests that they should be investigated further in order to develop safe and effective antioxidant and/or cytotoxic formulations.     

Preparation and characterization of a novel magnetized nanosphere as a carrier system for drug delivery using Plantago ovata Forssk. hydrogel combined with mefenamic acid as the drug model

The aim of the present study was to magnetize Plantago ovata Forssk. hydrogel and produce a nanosphere system to carrier mefenamic acid as the drug model. For this propose, P. ovata seeds hydrogel (POSH) was extracted and magnetized by Fe₃O₄ being functionalized using tetraethyl orthosilicate and trimethoxyvinysilane. Thereafter, mefenamic acid (MFA) was loaded on the carrier system. The final product, as the magnetic drug loaded nanosphere (Fe/POSH/MFA), was fully characterized through different techniques involving X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating-sample magnetometer (VSM), thermal gravimetric analysis (TGA), dynamic light scattering (DLS), and FT-IR spectroscopy. The results confirmed the successful production of the drug loaded nanosphere system with particles magnetization of 25 emu/g over a range size of 40–50 nm. However, the size distribution less than 100 nm was measured through DLS analysis. The hydrogel showed a pH sensitivity swelling behavior representing the best efficacy at pH 7.4. The efficiency of the drug encapsulation was found to be 64.35%. The drug releasing was studied using a dialysis bag at pH = 7.4. The highest in vitro drug releasing was found to be 57.3 ± 0.6% after 72 h, as well. The findings of the current report account for the potential use of P. ovata hydrogel as an effective delivery system for encapsulation of water insoluble basic drugs, e.g., MFA in a magnetized carrier system.     

An ultrasensitive electrochemical immunosensor for CA72-4 based on a signal amplification strategy of MoS2 nanoflower-supported Au nanoparticles

Accurate detection of cancer antigen 72-4 (CA72-4), a tumor-associated glycoprotein, is of great significance for gastric cancer diagnosis and immunotherapy monitoring. Modification of noble metal nanoparticles on transition metal dichalcogenides can significantly enhance functions, such as electron transport. Molybdenum disulfide gold nanoparticles nanocomposites (MoS₂-Au NPs) were prepared in this study and a series of characterization studies were carried out. In addition, a label-free, highly sensitive electrochemical immunosensor molybdenum disulfide -Au nanoparticles/Glassy carbon electrode (MoS₂-Au NPs/GCE) was also prepared and used for the detection of CA72-4. The electrochemical performance of the immunosensor was characterized by electrochemical techniques, such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results indicated that better MoS₂-Au NPs nanomaterials have been synthesized, and the prepared electrochemical immunosensor, MoS₂-Au NPs/GCE, showed excellent electrochemical performance. The sensor exhibited high detection sensitivity under optimal conditions, including an incubation time of 30 min, an incubation temperature of 25 °C, and a pH of 7.0. The electrochemical immunosensor also had a low detection limit of 2.0 × 10^?5 U/mL (S/N = 3) in a concentration range of 0.001–200 U/mL, with good selectivity, stability, and repeatability. In conclusion, this study provided a theoretical basis for the highly sensitive detection of tumor markers in clinical biological samples.     

Degradation-fragmentation of marine plastic waste and their environmental implications: A critical review

This review critically evaluates the plastic accumulation challenges and their environmental (primarily) and human (secondarily) impacts. It also emphasizes on their degradation and fragmentation phenomena under marine conditions. In addition, it takes into account the leachability of the various chemical substances (additives) embedded in plastic products to improve their polymeric properties and extend their life. Regardless of their effectiveness in enhancing the polymeric function of plastic products, these additives can potentially contaminate air, soil, food, and water. Several findings have shown that, regardless of their types and sizes, plastics can be degraded and/or fragmented under marine conditions. Therefore, the estimation of fragmentation and degradation rates via a reliable developed model is required to better understand the marine environmental status. The main parameter, which is responsible for initiating the fragmentation of plastics, is sunlight/UV radiation. Yet, UV- radiation alone is not enough to fragment some plastic polymer types under marine conditions, additional factors are needed such as mechanical abrasion. It should be also mentioned that most current studies on plastic degradation and fragmentation centered on the primary stages of degradation. Thus, further studies are needed to better understand these phenomena and to identify their fate and environmental effects.     

Application of HPLC to measure vanadium in environmental,biological and clinical matrices

Vanadate and vanadium compounds exist in many environmental, biological and clinical matrices, and despite the need only limited progress has been made on the analysis of vanadium compounds. The vanadium coordination chemistry of different oxidation states is known, and the result of the characterization and speciation analysis depends on the subsequent chemistry and the methods of analysis. Many studies have used a range of methods for the characterization and determination of metal ions in a variety of materials. One successful technique is high performance liquid chromatography (HPLC) that has been used mainly for measuring total vanadium level and metal speciation. Some cases have been reported where complexes of different oxidation states of vanadium have been separated by HPLC. Specifically reversed phase (RP) HPLC has frequently been used for the measurement of vanadium. Other HPLC methods such as normal phase, anion-exchange, cation-exchange, size exclusion and other RP-HPLC modes such as, ion-pair and micellar have been used to separate selected vanadium compounds. We will present a review that summarizes and critically analyzes the reported methods for analysis of vanadium salts and vanadium compounds in different sample matrices. We will compare various HPLC methods and modes including sample preparation, chelating reagents, mobile phase and detection methods. The comparison will allow us to identify the best analytical HPLC method and mode for measuring vanadium levels and what information such methods provide with regard to speciation and quantitation of the vanadium compounds.     

Application of stress induces ascorbate peroxidases of S. polyrhiza for green-synthesis Cu nanoparticles

The objective of this study was to assess the effects of stress on physiology/biochemical component of S. polyrhiza and its impact on CuNPs synthesis and bioethanol production. NaCl with RV5 provokes oxidative stress in S. polyrhiza and significantly increase MAD, Proline, H₂O₂, ROS, SOD and APX activity compare to control condition. Starch accumulation in S. polyrhiza was found 354% higher and correspond 4.4 times higher ethanol yield under stress condition compare to control. CuNPs were synthesized with an average size of 23–26 nm by purified fraction of APX having 37 KDa MW, 1.44 IU specific activity. Synthesized CuNPs were stable up to 15 consecutive cycles and potency against wide range of reactive dyes. The maximum remedial efficiency of synthesized CuNPs for COD and BOD was 55263.3 ± 3298.5 mg/m³min. and 30560.3 ± 1987.5 mg/m³min. respectively for RV5 wastewater. 0.072 mg/g of bioethanol was produced from the wet pulp remaining after nanoparticles synthesis. High efficiency of CuNPs and significant production of Ethanol, indicate that the feasibility for circular model for continuous industrial wastewater treatment.     

Bio and soft-imprinting lithography on bacterial cellulose films

Bacterial cellulose (BC) is a biocompatible polysaccharide produced by bacteria currently used in packaging, cosmetics, or health care. A highly attractive feature of BC is the possibility of patterning the BC pellicle during its biosynthesis, a concept coined as bio-lithography. BC-patterned films have demonstrated improved properties for cellular-guided growth, implant protection, or wound dressing. However, aspects such as the diversity and size of the features patterned, how those features withstand postprocessing steps, or if large areas can be patterned remain unanswered. Gathering knowledge on these characteristics could extend the use of patterned cellulose-based materials in emerging fields such as transient devices, nanogenerators, or microfluidics. Here, we show that bio-lithographed BC films present good-quality micropatterned features for various motifs (wells, pillars, and channels) in a wide range of sizes (from 200 to 5 μm) and areas as large as 70 cm². Besides, we have studied the fidelity of the motifs and the fiber organization for wet, supercritical, and oven-dried films. When wells and pillars were patterned, the x and y dimensions were faithfully replicated in the wet and dried samples, but only wet and supercritically dried films afforded mold accuracy in the z-direction. In addition, x/z ratio should be carefully considered for obtaining self-standing pillars. Finally, we compared bio-lithography and soft-imprint lithography. In the latter case, fiber alignment was not observed and the depth of the resulting features dramatically decreased; however, this technique allowed us to produce submicron features that remain after the rewetting of the BC films.     

Astragalus membranaceus ultrafine powder alleviates hyperuricemia by regulating the gut microbiome and reversing bile acid and adrenal hormone biosynthesis dysregulation

Ethnopharmacological relevanceMetabolic syndrome is closely related to the intestinal microbiota and disturbances in the host metabolome. Hyperuricemia (HUA), a manifestation of metabolic syndrome, can induce various cardiovascular diseases and gout, seriously affecting a patient’s quality of life. Astragalus membranaceus has a long history as a commonly used traditional Chinese medicine to treat kidney disease in China and East Asia.Materials and methodsWe compared the therapeutic effect of benzbromarone and two different doses Astragalus membranaceus ultrafine powder (AMUP) in rats with HUA. Ultra-performance liquid chromatography-mass spectrometer was used to analyze the AMUP metabolism in the plasma, urine, and feces. Further, 16S ribosome RNA sequencing and feces metabolomic were performed to capture the variation of the gut microbiota and metabolites changes before and after drug administration.ResultsAMUP had a notable impact on reducing blood uric acid levels while protecting the liver and kidney. Drug metabolism analysis demonstrated that effective constituent flavonoids are distributed in the blood, whereas saponins remain in the intestine. Gut microbiota analysis showed that low-dose AMUP ameliorated HUA-induced gut dysbiosis by reducing the abundance of harmful bacteria and increasing that of some beneficial bacteria with anti-inflammatory properties, such as Clostridia, Lachnospiraceae, and Muribaculaceae. In addition, HUA-induced changes in metabolite contents in bile acid and adrenal hormone biosynthesis pathways were restored after treatment with AMUP.ConclusionLow-dose AMUP exerts remarkable therapeutic effects on HUA by regulating the gut microbiome and mediating gut metabolism pathways associated with uric acid excretion.     

QSAR based virtual screening derived identification of a novel hit as a SARS CoV-229E 3CLpro Inhibitor: GA-MLR QSAR modeling supported by molecular Docking,molecular dynamics simulation and MMGBSA calculation approaches

Congruous coronavirus drug targets and analogous lead molecules must be identified as quickly as possible to produce antiviral therapeutics against human coronavirus (HCoV SARS 3CLpro) infections. In the present communication, we bear recognized a HIT candidate for HCoV SARS 3CLpro inhibition. Four Parametric GA-MLR primarily based QSAR model (R2:0.84, R2adj:0.82, Q2loo: 0.78) was once promoted using a dataset over 37 structurally diverse molecules along QSAR based virtual screening (QSAR-VS), molecular docking (MD) then molecular dynamic simulation (MDS) analysis and MMGBSA calculations. The QSAR-based virtual screening was utilized to find novel lead molecules from an in-house database of 100 molecules. The QSAR-vS successfully offered a hit molecule with an improved _PEC₅₀ value from 5.88 to 6.08. The benzene ring, phenyl ring, amide oxygen and nitrogen, and other important pharmacophoric sites are revealed via MD and MDS studies. Ile164, Pro188, Leu190, Thr25, His41, Asn46, Thr47, Ser49, Asn189, Gln191, Thr47, and Asn141 are among the key amino acid residues in the S1 and S2 pocket. A stable complex of a lead molecule with the HCoV SARS 3CLpro was discovered using MDS. MM-GBSA calculations resulted from MD simulation results well supported with the binding energies calculated from the docking results. The results of this study can be exploited to develop a novel antiviral target, such as an HCoV SARS 3CLpro Inhibitor.     

Antimycobacterial and anticancer activity of newly designed cinnamic acid hydrazides with favorable toxicity profile

A series of twelve novel hybrids of cinnamic acid and thiocarbohydrazones were designed, synthesized in high yield using a simple coupling strategy via acid chlorides, and evaluated for their impact against Mycobacterium tuberculosis (Mtb) and cancer cells survival. Among them, compound 3 demonstrated strong anti-Mtb activity by reducing bacilli survival for>90 % in all three treated Mtb isolates, whereas isoniazid and rifampicin did not. Moreover, compound 3 didn’t affect vitality of HepG-2 cells, implying on advantageous hepatotoxicity profile compared to current therapeutic options for tuberculosis. Compounds 2a and 3b displayed as strong inducers of apoptosis in A549 cells, both activating intrinsic caspase pathway and cell cycle arrest at the G0/G1 phase. Subsequent analyses disclosed differences in their activities, where 3b has ability to induce production of mitochondrial superoxide anions, while 2a significantly inhibited cellular mobility. More importantly, 3b considerably affected viability of HepG-2 and HaCaT cells, whereas 2a had moderate impact only on the later. Molecular modeling studies indicated high permeability and good absorption through the human intestine, and moderate aqueous solubility with poor blood–brain barrier permeability. In summary, our results reveal that novel compounds 3 and 2a represent promising agents for tuberculosis and cancer treatment, respectively, indicating that further investigation needs to be performed to clarify the mechanisms of their anti-Mtb and anticancer activity.     

Choline chloride – Urea deep eutectic solvent an efficient media for the preparation of metal nanoparticles

Metal nanoparticles are nanosized structures that have different potential applications in biological, chemical, medical, and agricultural fields because of their exotic characteristics. Their size ranges from 1 to 100 nm. Metal nanoparticles are either purer forms of metals (eg: Gold, Silver, Copper, Iron, etc.) or their compounds (eg: sulfides, hydroxides, oxides, etc.). Ionic liquids are generally used in the extraction of nanoparticles but they are challenging because of their indigent bio-degradability, bio-compatibility, and sustainability. So Deep Eutectic Solvent (DES) is reported as an alternative to ionic liquids in the formation of nanoparticles. The DESs are a complex of quaternary ammonium salts and hydrogen donors or metal salt. DESs contain higher non-symmetric ions which have lower lattice energy and hence they have a lower melting point. This research utilizes a novel DES (choline chloride – urea) as an effective solvent to produce mercuric sulfide (HgS), zirconium oxide (ZrO), manganese oxide (MnO), and copper oxide (CuO) nanoparticles. As a result, the production of these metal nanoparticles using Choline Chloride (C₅H₁₄ClNO) – Urea DES can be treated as a promising way in chemical manufacturing. The nanoparticles have been analyzed using Ultra Violet Spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD) and Energy Dispersive X-Ray Analysis (EDAX).     

Phytogenic fabrication of iron oxide nanoparticles and evaluation of their in vitro antibacterial and cytotoxic activity

Several metal-based nanoparticles (NPs) have been found to be toxic and are known to exert adverse health outcomes with irreversible side effects. This highlights the need to discover effective, stable, and biocompatible therapeutic components using natural sources. Here, a hexane extract of Nigella sativa seeds was used to synthesize iron oxide NPs (NS-IONPs) embedded with N. sativa phytoconstituents. The extract acted as a reducing agent that restricted the size of the NS-IONPs to 5–6 nm, signifying the potential to be cleared through the renal system. The fabricated NS-IONPs had a prominent effect on pathogenic gram-negative bacteria, E. coli (19.3 mm) and Salmonella typhi (14.2 mm) and lung cancer cells (lowest IC₅₀ of 18.75 µg/mL) mainly by binding to the phospholipid components of the cell membrane. This resulted in cell shrinkage and further inhibited cell growth. Transmission electron microscopy analyses revealed that the mechanisms of cellular NP uptake varied depending on the cell type. Accumulation of NS-IONPs inside the cell increased BAX expression and arrested the cells at the G0/G1 phase, thereby conspicuously extending the G0 phase to initiate necrosis. Thus, these finding suggest that the synthesized NS-IONPs exhibited high antibacterial activity and effective cytotoxicity against cancer cell lines A549 and HCT116 compared to IONPs. The innovation of the current study is that the biogenic fabrication of IONPs is simple and cost effective results in stable nanomaterial, NS-IONPs with potential antibacterial and anticancer activity, which can be explored furthermore for various biomedical applications.     

Enhanced skin anti-inflammatory and moisturizing action of gold nanoparticles produced utilizing Diospyros kaki fruit extracts

Inflammatory skin diseases (ISD) cause very severe itchy skin and dryness which is now a days an important issue which has to be taken care. Nanotechnology plays a main role in manufacturing cosmetic ingredients at a nanoscale size. Among different nanoparticles, gold (Au) is one of the non-toxic materials synthesized organically or inorganically. For synthesizing nanoparticles (NPs), using inorganic methods may cause some toxicity to cells, but using organic synthesis like plant extract is less toxic and environmentally friendly. Therefore, we synthesized DK-AuNPs using Diospyros kaki fruit extract. UPLC-MS/MS was used to evaluate phytochemicals responsible for converting salt into nanoparticles. The DK-AuNPs were characterized to confirm the formation of NPs. Furthermore, we analyzed the activity of DK-AuNPs on human keratinocytes (HaCaT cells). The DK-AuNPs showed 98.2 % cell survival upto 200 µg/mL against HaCaT cells. Additionally, compared to DK treatment, DK-AuNPs therapy decreased ROS production in TNF-α/IFN-γ (T + I) stimulated HaCaT cells by 68.7 %, whereas DK treatment reduced ROS generation by 27.8 %. Moreover, the skin anti-inflammatory potential and moisturizing effect of DK-AuNPs were analyzed using HaCaT cells. Furthermore, skin inflammatory activity biomarkers were downregulated through the MAPK/NFκB signaling pathway and showed significant inhibition by DK-AuNPs. Also, the skin moisturizing biomarkers such as HAS (1–3) were upregulated and HYAL (1–2) were downregulated by PI3K/AKT/NFκB through HAS2 regulation. Therefore, skin anti-inflammatory and moisturizing activity were enhanced by treatment with DK-AuNPs. In summary, we conclude that the DK-AuNPs could be a new alternative for skin disease.     

Pharmacophore model-aided virtual screening combined with comparative molecular docking and molecular dynamics for identification of marine natural products as SARS-CoV-2 papain-like protease inhibitors

Targeting SARS-CoV-2 papain-like protease using inhibitors is a suitable approach for inhibition of virus replication and dysregulation of host anti-viral immunity. Engaging all five binding sites far from the catalytic site of PLpro is essential for developing a potent inhibitor. We developed and validated a structure-based pharmacophore model with 9 features of a potent PLpro inhibitor. The pharmacophore model-aided virtual screening of the comprehensive marine natural product database predicted 66 initial hits. This hit library was downsized by filtration through a molecular weight filter of ≤ 500 g/mol. The 50 resultant hits were screened by comparative molecular docking using AutoDock and AutoDock Vina. Comparative molecular docking enables benchmarking docking and relieves the disparities in the search and scoring functions of docking engines. Both docking engines retrieved 3 same compounds at different positions in the top 1 % rank, hence consensus scoring was applied, through which CMNPD28766, aspergillipeptide F emerged as the best PLpro inhibitor. Aspergillipeptide F topped the 50-hit library with a pharmacophore-fit score of 75.916. Favorable binding interactions were predicted between aspergillipeptide F and PLpro similar to the native ligand XR8-24. Aspergillipeptide F was able to engage all the 5 binding sites including the newly discovered BL2 groove, site V. Molecular dynamics for quantification of Cα-atom movements of PLpro after ligand binding indicated that it exhibits highly correlated domain movements contributing to the low free energy of binding and a stable conformation. Thus, aspergillipeptide F is a promising candidate for pharmaceutical and clinical development as a potent SARS-CoV-2 PLpro inhibitor.     

Synthesis,characterization, and application of griseofulvin surface molecularly imprinted polymers as the selective solid phase extraction sorbent in rat plasma samples

In present study, an investigation was carried out to develop and validate an analytical method for the selective extraction and determination of griseofulvin (GSF) from plasma samples. For this purpose, a rational approach was made to synthesize and characterize the surface molecularly imprinted polymers (SMIPs). The SMIPs were utilized as solid phase extraction (SPE) sorbents. The SMIPs were prepared by using GSF as template molecule on the surface of modified silica particles through a non-covalent technique. The particles demonstrated high adsorption capacity (119.1 µg/mL), fast adsorption equilibrium time (30 min) and good recognition selectivity for the template drug. The scanning electron microscopy and infrared spectroscopy were used to explain the structural and morphological characteristics of the SMIPs and surface non-imprinted polymers. The SPE method was combined with HPLC for plasma analysis. The method validation results demonstrated that the established method possessed good linearity for GSF ranging from 0.1 to 50 µg/mL (R² = 0.997). The limit of detection for this method was 0.02 µg/mL for rat plasma samples. The recoveries of GSF from spiked plasma samples were (90.7–97.7%) and relative standard deviations were (0.9–4.5%). Moreover, the SMIPs as selective SPE sorbent can be reused more than 8 times which is a clear advantage over commercial SPE sorbents. Finally, the usefulness of the proposed strategy was assessed by extraction and detection of GSF in real rat plasma samples.