Textile wastewater laden with dyes has emerged as a source of water pollution. This possesses a challenge in its effective treatment using a single functional material. In respond to this technological constraint, this work presents multifunctional cotton fabrics (CFs) within a single, streamlined preparation process. This approach utilizes the adherence of Ag NPs (nanoparticles) using Si binder on the surface of CFs, resulting in Ag-coated CFs through a pad dry method. The prepared samples were characterized using scanning electron microscope-energy dispersive X-ray electroscopy (SEM-EDS), thermal gravimetric analysis (TGA), Fourier transformation infrared (FT-IR). It was found that the FT-IR spectra of Ag NPs-coated CFs had peaks appear at 3400, 2900, and 1200 cm-1, implying the stretching vibrations of O-H, C-H, and C-O, respectively. Based on the EDX analysis, the presence of C, O, and Ag related to the coated CFs were detected. After coating the CFs with varying concentrations of Ag NPs (1%, 2% and 3% (w/w)), they were used to remove dyes. Under the same concentration of 10 mg/L and optimized pH 7.5 and 2 h of reaction time, 3% (w/w) Ag-coated CFs exhibited a substantial MB degradation of 98 %, while removing 95% of methyl orange, 85% of rhodamine B, and 96% of Congo red, respectively, following 2 h of Vis exposure. Ag NPs had a strong absorption at 420 nm with 2.51 eV of energy band gap. Under UV irradiation, electrons excited and produced free radicals that promoted dyes photodegradation. The oxidation by-products included p-dihydroxybenzene and succinic acid. Spent Ag-coated CFs attained 98% of regeneration efficiency. The utilization of Ag-coated CFs as a photocatalyst facilitated treated effluents to meet the required discharge standard of lower than 1 mg/L mandated by national legislation. The integration of multifunctional CFs in the treatment system presents a new option for tackling water pollution due to dyes.
Microbial fuel cells (MFCs) are based on the biochemical reaction of microorganisms to decompose organic wastewater for converting chemical energy into power energy. MFCs are considered an environmentally friendly technology that is gaining popularity due to their simultaneous digestion and energy production abilities. To enhance its real application in wastewater treatment, this study proposes to use a non-woven material for replacing the usage of expensive membranes in MFCs. In addition, the study aims to consider a series of different aeration areas of cathode electrodes for finding an optional design. Results have shown that the adoption of non-woven with 0.45 μm can effectively prohibit the diffusion of oxygen into the anode chamber. Moreover, the non-woven material played an important role as an interface between the anode and cathode, enhancing the MFC performance. The usage of suitable non-woven material can replace the role of the membrane when applied in real wastewater applications. The results have shown that the case study where a combination of a 50% aeration area of the cathode electrodes with 25% exposure of the cathode plate in the air yielded relatively better aeration in terms of a higher current density of 250 mA/m2, higher power density of 220 mW/m2, and higher open voltage circuit of 0.4 V, compared to other case studies considered. These results indicate the optimal aeration configuration for MFCs applied in commercial wastewater treatment in the future.
Plants in the genus Erythrina is a potential source of chemical constituents, one of which is flavonoids, which have diverse bioactivities. To date, literature on the flavonoids from the genus Erythrina has only highlighted the phytochemical aspects, so this review article will discuss isolation techniques and strategies for the first time. More than 420 flavonoids have been reported in the Erythrina genus, which are grouped into 17 categories. These flavonoid compounds were obtained through isolation techniques and strategies using polar, semi-polar, and non-polar solvents. Various chromatographic techniques have been developed to isolate flavonoids using column flash chromatography, quick column chromatography, centrifugally accelerated thin-layer chromatography, radial chromatography, medium-pressure column chromatography, semi-preparative high-performance liquid chromatography, and preparative high-performance liquid chromatography. Chromatographic processes for isolating flavonoids can be optimized using multivariate statistical applications such as response surface methodology with central composite design, Box-Behnken design, Doehlert design, and mixture design.
Miri River is a tropical river in Borneo that drains on flat terrain and urbanised area and debauches into the South China Sea. This paper documents the environmental status of this river, and provides an insight into the provenance using bulk chemistry of the sediments, and brings out the geochemical mobility, bioavailability, and potential toxicity of some critical elements based on BCR sequential extraction. The sediments are intense to moderately weathered and recycled products of Neogene sedimentary rocks. The hydrodynamic characteristics of the river favoured an upstream section dominated by fine sand, while the downstream sediments are medium silt. Based on the bulk geochemistry, the Miri River sediments are moderate to considerably contaminated by Cu, Mo, and As in the upstream and by Sb, As and Cu in the downstream. The potential ecological risk values are low except Cu and a significant biological impact is expected in downstream due to Cu, As, Zn and Cr. The mobility, bioavailability and Risk Assessment Code values for Zn and Mn are higher and thus may pose moderate to very high risk to aquatic organisms. Though a high bulk concentration of Cu is observed, the association of Cu with the bioavailable fraction is low.
Deep eutectic solvents (DESs) composed by amino acids (L-arginine, L-proline, L-alanine) as the hydrogen bond acceptors (HBAs) and carboxylic acids (formic acid, acetic acid, lactic acid, levulinic acid) as hydrogen bond donors (HBDs) were prepared and used for the dissolution of dealkaline lignin (DAL). The mechanism of lignin dissolution in DESs was explored at molecular level by combining the analysis of Kamlet-Taft (K-T) solvatochromic parameters, FTIR spectrum and density functional theory (DFT) calculations of DESs. Firstly, it was found that the formation of new hydrogen bonds between lignin and DESs mainly drove the dissolution of lignin, which were accompanied by the erosion of hydrogen bond networks in both lignin and DESs. The nature of hydrogen bond network within DESs was fundamentally determined by the type and number of functional groups in both HBA and HBD, which affected its ability to form hydrogen bond with lignin. One hydroxyl group and carboxyl group in HBDs provided active protons, which facilitated proton-catalyzed cleavage of β-O-4, thus enhancing the dissolution of DESs. The superfluous functional group resulted in more extensive and stronger hydrogen bond network in the DESs, thus decreasing the lignin dissolving ability. Moreover, it was found that lignin solubility had a closed positive correlation with the subtraction value of α and β (net hydrogen donating ability) of DESs. Among all the investigated DESs, L-alanine/formic acid (1:3) with the strong hydrogen-bond donating ability (acidity), weak hydrogen-bond accepting ability (basicity) and small steric-hindrance effect showed the best lignin dissolving ability (23.99 wt%, 60 °C). On top of that, the value of α and β of L-proline/carboxylic acids DESs showed some positive correlation with the global electrostatic potential (ESP) maxima and minima of the corresponding DESs respectively, indicating the analysis of ESP quantitative distributions of DESs could be an effective tool for DESs screening and design for lignin dissolution as well as other applications.
In biomedical implant technology, nanosurface such as titania nanotube arrays (TNA) could provide better cellular adaptation, especially for long-term tissue acceptance response. Mechanotransduction activities of TNA nanosurface could involve the cytoskeleton remodeling mechanism. However, there is no clear insight into TNA mechano-cytoskeleton remodeling activities, especially computational approaches. Epithelial cells have played critical interface between biomedical implant surface and tissue acceptance, particularly for long-term interaction. Therefore, this study investigates genomic responses that are responsible for cell-TNA mechano-stimulus using epithelial cells model. Findings suggested that cell-TNA interaction may improve structural and extracellular matrix (ECM) support on the cells as an adaptive response toward the nanosurface topography. More specifically, the surface topography of the TNA might improve the cell polarity and adhesion properties via the interaction of the plasma membrane and intracellular matrix responses. TNA nanosurface might engross the cytoskeleton remodeling activities for multidirectional cell movement and cellular protrusions on TNA nanosurface. These observations are supported by the molecular docking profiles that determine proteins' in silico binding mechanism on TNA. This active cell-surface revamping would allow cells to adapt to develop a protective barrier toward TNA nanosurface, thus enhancing biocompatibility properties distinctly for long-term interaction. The findings from this study will be beneficial toward nano-molecular knowledge of designing functional nanosurface technology for advanced medical implant applications.
In this study, biochar produced from sunflower seeds husk was activated through ZnCl2 to support the NiCo2O4 nanoparticles (NiCo2O4@ZSF) in catalytic activation of peroxymonosulfate (PMS) toward tetracycline (TC) removal from aqueous solution. The good dispersion of NiCo2O4 NPs on the ZSF surface provided sufficient active sites and abundant functional groups for the adsorption and catalytic reaction. The NiCo2O4@ZSF activating PMS showed high removal efficiency up to 99% after 30 min under optimal condition ([NiCo2O4@ZSF] = 25 mg L-1, [PMS] = 0.04 mM, [TC] = 0.02 mM and pH = 7). The catalyst also exhibited good adsorption performance with a maximum adsorption capacity of 322.58 mg g-1. Sulfate radicals (SO4•-), superoxide radical (O2•-), and singlet oxygen (1O2) played a decisive role in the NiCo2O4@ZSF/PMS system. In conclusion, our research elucidated the production of highly efficient carbon-based catalysts for environmental remediation, and also emphasized the potential application of NiCo2O4 doped biochar.
Cancer is one of the leading causes of mortality worldwide; nearly 10 million people died from it in 2020. The high mortality rate results from the lack of effective screening approaches where early detection cannot be achieved, reducing the chance of early intervention to prevent cancer development. Non-invasive and deep-tissue imaging is useful in cancer diagnosis, contributing to a visual presentation of anatomy and physiology in a rapid and safe manner. Its sensitivity and specificity can be enhanced with the application of targeting ligands with the conjugation of imaging probes. Phage display is a powerful technology to identify antibody- or peptide-based ligands with effective binding specificity against their target receptor. Tumour-targeting peptides exhibit promising results in molecular imaging, but the application is limited to animals only. Modern nanotechnology facilitates the combination of peptides with various nanoparticles due to their superior characteristics, rendering novel strategies in designing more potent imaging probes for cancer diagnosis and targeting therapy. In the end, a myriad of peptide candidates that aimed for different cancers diagnosis and imaging in various forms of research were reviewed.
The Aglaia genus, a member of the Meliaceae family, is generally recognized to include a number of secondary metabolite compounds with diverse structures and biological activities, including triterpenoids. Among the members of this genus, Aglaia cucullata has been reported to have unique properties and thrives exclusively in mangrove ecosystems. This plant is also known to contain various metabolites, such as flavaglines, bisamides, and diterpenoids, but there are limited reports on the isolation of triterpenoid compounds from its stem bark. Therefore, this research attempted to isolate and elucidate seven triterpenoids belonging to dammarane-type (1-7) from the stem bark of Aglaia cucullata. The isolated compounds included 20S,24S-epoxy-3α,25-dihydroxy-dammarane (1), dammaradienone (2), 20S-hydroxy-dammar-24-en-3-on (3), eichlerianic acid (4), (20S,24RS)-23,24-epoxy-24-methoxy-25,26,27-tris-nor dammar-3-one (5), 3α-acetyl-cabraleahydroxy lactone (6), and 3α-acetyl-20S,24S-epoxy-3α,25-dihydroxydammarane (7). Employing spectroscopic techniques, the chemical structures of the triterpenoids were identified using FTIR, NMR, and HRESITOF-MS. The cytotoxic activity of compounds 1-7 was tested with the PrestoBlue cell viability reagent against MCF-7 breast cancer, B16-F10 melanoma, and CV-1 normal kidney fibroblast cell lines. The results displayed that compound 5 had the highest level of bioactivity compared to the others. Furthermore, the IC50 values obtained were more than 100 μM, indicating the low potential of natural dammarane-type triterpenoids as anticancer agents. These findings provided opportunities for further studies aiming to increase their cytotoxic activities through semi-synthetic methods.
A graphene oxide mediated hybrid nano system for pH stimuli-responsive and in vitro drug delivery targeted for cancer was described in this study. Graphene oxide (GO) functionalized Chitosan (CS) mediated nanocarrier capped with xyloglucan (XG) was fabricated with and without Kappa carrageenan (κ-C) from red seaweed, Kappaphycus alverzii, as an active drug. FTIR, EDAX, XPS, XRD, SEM and HR-TEM studies were carried out for GO-CS-XG nanocarrier loaded with and without active drugs to understand the physicochemical properties. XPS (C1s, N1s and O1s) confirmed the fabrications of XG and functionalization of GO by CS via the binding energies at 284.2 eV, 399.4 eV and 531.3 eV, respectively. The amount of drug loaded in vitro was 0.422 mg/mL. The GO-CS-XG nanocarrier showed a cumulative drug release of 77 % at acidic pH 5.3. In contrast to physiological conditions, the release rate of κ-C from the GO-CS-XG nanocarrier was considerably higher in the acidic condition. Thus, a pH stimuli-responsive anticancer drug release was successfully achieved with the GO-CS-XG-κ-C nanocarrier system for the first time. The drug release mechanism was carried out using various kinetic models that showed a mixed release behavior depending on concentration and diffusion/swelling mechanism. The best-fitting model which supports our release mechanism are zero order, first order and Higuchi models. GO-CS-XG and κ-C loaded nanocarrier biocompatibility were determined by in vitro hemolysis and membrane stabilization studies. MCF-7 and U937 cancer cell lines were used to study the cytotoxicity of the nanocarrier by MTT assay, which indicates excellent cytocompatibility. These findings support the versatile use of a green renewable biocompatible GO-CS-XG nanocarrier as targeted drug delivery and potential anticancer agent for therapeutic purposes.
Paeonol is a naturally existing bioactive compound found in the root bark of Paeonia suffruticosa and it is traditionally used in Chinese medicine for the prevention and management of cardiovascular diseases. To date, a great deal of studies has been reported on the pharmacological effects of paeonol and its mechanisms of action in various diseases and conditions. In this review, the underlying mechanism of action of paeonol in cardiovascular disease has been elucidated. Recent studies have revealed that paeonol treatment improved endothelium injury, demoted inflammation, ameliorated oxidative stress, suppressed vascular smooth muscle cell proliferation, and repressed platelet activation. Paeonol has been reported to effectively protect the cardiovascular system either employed alone or in combination with other traditional medicines, thus, signifying it could be a hypothetically alternative or complementary atherosclerosis treatment. This review summarizes the biological and pharmacological activities of paeonol in the treatment of cardiovascular diseases and its associated underlying mechanisms for a better insight for future clinical practices.
The delineation of the complex biosynthesis of the potent antibiotic mupirocin, which consists of a mixture of pseudomonic acids (PAs) isolated from Pseudomonas fluorescens NCIMB 10586, presents significant challenges, and the timing and mechanisms of several key transformations remain elusive. Particularly intriguing are the steps that process the linear backbone from the initial polyketide assembly phase to generate the first cyclic intermediate PA-B. These include epoxidation as well as incorporation of the tetrahydropyran (THP) ring and fatty acid side chain required for biological activity. Herein, we show that the mini-module MmpE performs a rare online (ACP-substrate) epoxidation and is integrated ('in-cis') into the polyketide synthase via a docking domain. A linear polyketide fragment with six asymmetric centres was synthesised using a convergent approach and used to demonstrate substrate flux via an atypical KS0 and a previously unannotated ACP (MmpE_ACP). MmpE_ACP-bound synthetic substrates were critical in demonstrating successful epoxidation in vitro by the purified MmpE oxidoreductase domain. Alongside feeding studies, these results confirm the timing as well as chain length dependence of this selective epoxidation. These mechanistic studies pinpoint the location and nature of the polyketide substrate prior to the key formation of the THP ring and esterification that generate PA-B.
The rapid consumption of metals and unorganized disposal have led to unprecedented increases in heavy metal ion concentrations in the ecosystem, which disrupts environmental homeostasis and results in agricultural biodiversity loss. Mitigation and remediation plans for heavy metal pollution are largely dependent on the discovery of cost-effective, biocompatible, specific, and robust detectors because conventional methods involve sophisticated electronics and sample preparation procedures. Carbon dots (CDs) have gained significant importance in sensing applications related to environmental sustainability. Fluorescence sensor applications have been enhanced by their distinctive spectral properties and the potential for developing efficient photonic devices. With the recent development of biomass-functionalized carbon dots, a wide spectrum of multivalent and bivalent transition metal ions responsible for water quality degradation can be detected with high efficiency and minimal toxicity. This review explores the various methods of manufacturing carbon dots and the biochemical mechanisms involved in metal detection using green carbon dots for sensing applications involving Cu (II), Fe (III), Hg (II), and Cr (VI) ions in aqueous systems. A detailed discussion of practical challenges and future recommendations is presented to identify feasible design routes.
Green tea has garnered widespread interest in the past decades due to its content of health-beneficial polyphenols and catechins, besides reportedly exhibiting activities for the prevention, and possibly treatment, of many modern-life-associated afflictions. Hence, the functional food potential of health-beneficial beverages such as green tea is widely and commercially promoted. Biotransformation of green tea extract using enzymes such as tannase ostensibly enhances its beneficial well-being properties and disease-preventing functionalities. The tannase-treated green tea catechins may exhibit enhanced, amongst others, antioxidant, anti-tumour, anti-wrinkle, anti-inflammatory, anti-obesity and anti-sarcopenia properties compared to native green tea extract. Nonetheless, the health benefits and therapeutic and toxicological effects associated with these compounds, before and after tannase treatment, present a scientific gap for detailed studies. Accordingly, the review surveys the literature from the late twentieth century until the year 2023 related to the aforementioned important aspects.
In this work, porous glass beads grafted with polyethylene glycol (PEG) were used as an adsorbent to purify lipase from Burkholderia metallica in column chromatography. The purification parameters viz. salt stability, types and concentrations of PEG and salt, pH of the binding solution, and flow rate were studied to determine the performance of the purification system in an XK16/20 column. The crude lipase was mixed with different types and concentrations of salts 1-5% (w/w) (sodium citrate, potassium citrate, and sodium acetate) and subjected to the column containing the polymeric glass bead. One-variable-at-a-time experimentation revealed that 20% (w/w) PEG 6000 g/mol impregnated glass beads with a binding solution of 5% sodium citrate at pH 7.7, a flow rate of 1.0 mL/min and extraction time of 10 min resulted in the highest purification factor and recovery yield at 3.67 and 88%, respectively. The purified lipase has 55 ∼ 60 kDa molecular mass. The outcome of the study showed PEG could be applied to modify the inert glass beads into polymeric form, providing a biocompatible and mild separation condition for lipase. Thus, PEG could be successfully applied for the purification of lipase from B. metallica fermentation broth using column chromatography.
Targeting vascular endothelial growth factor receptor (VEFGR) and its co-receptor neuropilin-1 (NRP-1) is an interesting vascular strategy. tLyp-1 is a tumor-homing and penetrating peptide of 7 amino acids (CGNKRTR). It is a truncated form of Lyp-1 (CGNKRTRGC), which is known to target NRP-1 receptor, with high affinity and specificity. It is mediated by endocytosis via C-end rule (CendR) internalization pathway. The aim of this study is to evaluate the importance of each amino acid in the tLyp-1 sequence through alanine-scanning (Ala-scan) technique, during which each of the amino acid in the sequence was systematically replaced by alanine to produce 7 different analogues. In silico approach through molecular docking and molecular dynamics are employed to understand the interaction between the peptide and its analogues with the NRP-1 receptor, followed by in vitro ligand binding assay study. The C-terminal Arg is crucial in the interaction of tLyp-1 with NRP-1 receptor. Substituting this residue dramatically reduces the affinity of this peptide which is clearly seen in this study. Lys-4 is also important in the interaction, which is confirmed via the in vitro study and the MM-PBSA analysis. The finding in this study supports the CendR, in which the presence of R/K-XX-R/K motif is essential in the binding of a ligand with NRP-1 receptor. This presented work will serve as a guide in the future work pertaining the development of active targeting agent towards NRP-1 receptor.
Sweat analysis offers non-invasive real-time on-body measurement for wearable sensors. However, there are still gaps in current developed sweat-sensing devices (SSDs) regarding the concerns of mixing fresh and old sweat and real-time measurement, which are the requirements to ensure accurate the measurement of wearable devices. This review paper discusses these limitations by aiding model designs, features, performance, and the device operation for exploring the SSDs used in different sweat collection tools, focusing on continuous and non-continuous flow sweat analysis. In addition, the paper also comprehensively presents various sweat biomarkers that have been explored by earlier works in order to broaden the use of non-invasive sweat samples in healthcare and related applications. This work also discusses the target analyte's response mechanism for different sweat compositions, categories of sweat collection devices, and recent advances in SSDs regarding optimal design, functionality, and performance.
This work investigates the use of novel BiOI@ZIF-8 nanocomposite for the removal of acetaminophen (Ace) from synthetic wastewater. The samples were analyzed using FTIR, XRD, XPS, DRS, PL, FESEM-EDS, and ESR techniques. The effects of the loading capacity of ZIF-8 on the photocatalytic oxidation performance of bismuth oxyiodide (BiOI) were studied. The photocatalytic degradation of Ace was maximized by optimizing pH, reaction time and the amount of photocatalyst. On this basis, the removal mechanisms of the target pollutant by the nanocomposite and its photodegradation pathways were elucidated. Under optimized conditions of 1 g/L of composite, pH 6.8, and 4 h of reaction time, it was found that the BiOI@ZIF-8 (w/w = 1:0.01) nanocomposite exhibited the highest Ace removal (94%), as compared to that of other loading ratios at the same Ace concentration of 25 mg/L. Although this result was encouraging, the treated wastewater still did not satisfy the required statutory of 0.2 mg/L. It is suggested that the further biological processes need to be adopted to complement Ace removal in the samples. To sustain its economic viability for wastewater treatment, the spent composite still could be reused for consecutive five cycles with 82% of regeneration efficiency. Overall, this series of work shows that the nanocomposite was a promising photocatalyst for Ace removal from wastewater samples.
A bio-assay guided fractionation strategy based on cholinesterase assay combined with 13C NMR-based dereplication was used to identify active metabolites from the bark of Mesua lepidota. Eight compounds were identified with the aid of the 13C NMR-based dereplication software, MixONat, i.e., sitosterol (1), stigmasterol (2), α-amyrin (3), friedelin (6), 3β-friedelinol (7), betulinic acid (9), lepidotol A (10) and lepidotol B (11). Further bio-assay guided isolation of active compounds afforded one xanthone, pyranojacareubin (12) and six coumarins; lepidotol A (10), lepidotol B (11), lepidotol E (13), lepidotin A (14), and lepidotin B (15), including a new Mammea coumarin, lepidotin C (16). All the metabolites showed strong to moderate butyrylcholinesterase (BChE) inhibition. Lepidotin B (15) exhibited the most potent inhibition towards BChE with a mix-mode inhibition profile and a Ki value of 1.03 µM. Molecular docking and molecular dynamics simulations have revealed that lepidotin B (15) forms stable interactions with key residues within five critical regions of BChE. These regions encompass residues Asp70 and Tyr332, the acyl hydrophobic pocket marked by Leu286, the catalytic triad represented by Ser198 and His438, the oxyanion hole (OH) constituted by Gly116 and Gly117, and the choline binding site featuring Trp82. To gauge the binding strength of lepidotin B (15) and to pinpoint pivotal residues at the binding interface, free energy calculations were conducted using the Molecular Mechanics Generalized Born Surface Area (MM-GBSA) approach. This analysis not only predicted a favourable binding affinity for lepidotin B (15) but also facilitated the identification of significant residues crucial for the binding interaction.
Cancer is the main cause of death worldwide, so the discovery of new and effective therapeutic agents must be urgently addressed. Diatoms are rich in minerals and secondary metabolites such as saturated and unsaturated fatty acids, esters, acyl lipids, sterols, proteins, and flavonoids. These bioactive compounds have been reported as potent anti-cancer, anti-oxidant and anti-bacterial agents. Diatoms are unicellular photosynthetic organisms, which are important in the biogeochemical circulation of silica, nitrogen, and carbon, attributable to their short growth-cycle and high yield. The biosilica of diatoms is potentially effective as a carrier for targeted drug delivery in cancer therapy due to its high surface area, nano-porosity, bio-compatibility, and bio-degradability. In vivo studies have shown no significant symptoms of tissue damage in animal models, suggesting the suitability of a diatoms-based system as a safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms' microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated.