A Highly Sensitive Lateral-Flow Strip Using Latex Microspheres to Detect NGAL in Urine Samples.

The incidence of kidney disease is increasing worldwide. Rapid and cost-effective approaches for early detection help prevent this disease. Neutrophil gelatinase-associated lipocalin protein (NGAL) is a novel biomarker for acute kidney injury (AKI) and chronic kidney disease (CKD). We aimed to develop a lateral flow strip (LFS) based on a lateral flow immunoassay method (LFIA), using latex microspheres (LMs) as a color labeling to detect NGAL in urine. The performance and potential of the developed LMs-LFS at a point-of-care (POC) testing were evaluated. The results showed that LMs-LFS successfully detected urinary NGAL within 15 min with high specificity without cross-reactivity to or interference from other endogenous substances in urine. The visual limit of detection (vLOD) was 18.75 ng/mL, and the limit of detection (LOD) was 1.65 ng/mL under the optimum condition. The LMs-LFS developed in this study showed a high correlation with the enzyme-linked immunosorbent assay (ELISA) method (R 2 = 0.973, n = 60 urine specimens) for detecting NGAL in urine. The LMs-LFS remained stable for at least six months at room temperature. The LMs-LFS can be a rapid, sensitive, and specific tool for the diagnosis and follow-up of renal disorders at the POC.

Development of gold nanoparticle-based lateral-flow strips for NGAL protein detection in urine samples.

This study focuses on enhancing the sensitivity of lateral-flow strips (LFSs) based on gold nanoparticles (AuNPs) for the detection of Neutrophil Gelatinase-Associated Lipocalin (NGAL) protein in urine samples. Several sizes of AuNP-based LFS biosensors were tested to optimize colorimetric signals for NGAL detection based on improved conjugation conditions. AuNPs of 39.8 nm diameter at pH 8 were the most sensitive for the detection of NGAL. Through systematic enhancements to the AuNP-based LFS, the study significantly improves the sensitivity, enabling the reliable detection of NGAL protein in urine samples at a level as low as 12.5 ng mL-1. These advances contribute to the refinement of diagnostic tools for the early detection of kidney injury, specifically in cases associated with the presence of NGAL protein, offering a more precise and effective screening approach.

Revealing the pH-dependent conformational changes in sol g 2.1 protein and potential ligands binding.

Sol g 2, a major protein found in the venom of the tropical fire ant (Solenopsis geminata), is well-known for its ability to bind various hydrophobic molecules. In this study, we investigate the binding activity of recombinant Sol g 2.1 protein (rSol g 2.1) with potential molecules, including (E)-ß-Farnesene, α-Caryophyllene, and 1-Octen-3-ol at different pH levels (pH 7.4 and 5.5) using fluorescence competitive binding assays (FCBA). Our results revealed that Sol g 2.1 protein has higher affinity binding with these ligands at neutral pH. Relevance to molecular docking and molecular dynamics simulations were utilized to provide insights into the stability and conformational dynamics of Sol g 2.1 and its ligand complexes. After simulation, we found that Sol g 2.1 protein has higher affinity binding with these ligands as well as high structural stability at pH 7.4 than at an acidic pH level, indicating by RMSD, RMSF, Rg, SASA, and principal component analysis (PCA). Additionally, the Sol g 2.1 protein complexes at pH 7.4 showed significantly lower binding free energy (∆Gbind) and higher total residue contributions, particularly from key non-polar amino acids such as Trp36, Met40, Cys62, and Ile104, compared to the lower pH environment. These explain why they exhibited higher binding affinity than the lower pH. Therefore, we suggested that Sol g 2.1 protein is a pH-responsive carrier protein. These findings also expand our understanding of protein-ligand interactions and offer potential avenues for the development of innovative drug delivery strategies targeting Sol g 2.1 protein.

Egg white hydrolysate peptides act as antimicrobial and anti-inflammatory agents for acne.

A simple method to generate antibacterial peptides by alkaline hydrolysis of hen egg whites is reported. The method reproducibly generates short peptides with molecular weight of less than 14.4 kDa that exhibit low to no cytotoxicity on RAW 264.7 macrophage cells, but do inhibit the bacterial growth of Cutibacterium acnes (C. acnes), Staphylococcus aureus (S. aureus) and antibiotic-resistant S. aureus (MRSA), while also reducing nitric oxide production from heat-killed C. acnes-treated RAW 264.7 cells. Peptidomics revealed at least thirty peptides within the complex mixture, of which eight were evaluated individually. Three peptides (PK8, EE9 and RP8) were potent anti-inflammation and antibacterial agents, but notably the complex egg white hydrolysate (EWH) was more effective than the individual peptides. Electron microscopy suggests the antibacterial mechanism of both the hydrolysate and the selected peptides is through disruption of the cell membrane of C. acnes. These findings suggest that EWH and EWH-derived peptides are promising candidates for infection and inflammation treatment, particularly in managing acne and combating antibiotic-resistant bacteria like MRSA.

DNA aptamer-functionalized PDA nanoparticles: from colloidal chemistry to biosensor applications.

Polydopamine nanoparticles (PDA NPs) are widely utilized in the field of biomedical science for surface functionalization because of their unique characteristics, such as simple and low-cost preparation methods, good adhesive properties, and ability to incorporate amine and oxygen-rich chemical groups. However, challenges in the application of PDA NPs as surface coatings on electrode surfaces and in conjugation with biomolecules for electrochemical sensors still exist. In this work, we aimed to develop an electrochemical interface based on PDA NPs conjugated with a DNA aptamer for the detection of glycated albumin (GA) and to study DNA aptamers on the surfaces of PDA NPs to understand the aptamer-PDA surface interactions using molecular dynamics (MD) simulation. PDA NPs were synthesized by the oxidation of dopamine in Tris buffer at pH 10.5, conjugated with DNA aptamers specific to GA at different concentrations (0.05, 0.5, and 5 µM), and deposited on screen-printed carbon electrodes (SPCEs). The charge transfer resistance of the PDA NP-coated SPCEs decreased, indicating that the PDA NP composite is a conductive bioorganic material. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed that the PDA NPs were spherical, and dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy data indicated the successful conjugation of the aptamers on the PDA NPs. The as-prepared electrochemical interface was employed for the detection of GA. The detection limit was 0.17 µg/mL. For MD simulation, anti-GA aptamer through the 5'terminal end in a single-stranded DNA-aptamer structure and NH2 linker showed a stable structure with its axis perpendicular to the PDA surface. These findings provide insights into improved biosensor design and have demonstrated the potential for employing electrochemical PDA NP interfaces in point-of-care applications.

A New Source and Large Quantity of Resveratrol in Cratoxylum Species and Their Activities on Normal Human and Cancer Cells.

Cratoxylum formosum ssp. formosum (Cff), C. formosum ssp. pruniflorum (Cfp), and C. sumatranum (Cs) were investigated for phytochemical analysis. Toxicity testing, programmed cell death, and cell cycle arrest were tested on CHL-1, HCT-116, and HepG2 cancer cell lines, and human normal PBMCs. The results are revealed in the following order. The phytochemical percentages varied in each species, the quantity and concentration of α-amyrin and resveratrol were 0.038 mg/g and 0.955 mg/mL, and 0.064 mg/g and 0.640 mg/mL. The most studied Cratoxylum extracts showed IC50 values in PBMCs and cancer cell lines except for the hexane Cff and ethanol Cfp extracts. All studied extracts did not induce DNA breaks in PBMCs but caused significant DNA breaks in the cancer cell lines. All studied extracts induced both apoptosis and necrosis in cancer cell lines, and the DNA quantity in the S and G2-M phases decreased significantly but did not induce apoptosis and necrosis in PBMCs. Except for the ethanolic extracts of Cff and Cfp that induced PBMCs apoptosis and necrosis, these data confirmed that the three studied Cratoxylum samples have inhibiting properties for the growth of cancer cells and low toxicity to PBMCs. Cs showed more toxicity to cancer cell lines than Cf and cisplatin.

Development in competitive immunoassay of a point-of-care testing for cotinine (COT) detection in urine.

We present a sensitive and selective lateral flow immunoassay (LFIA) for cotinine (COT), the primary metabolite of nicotine. COT is widely recognized as a superior biomarker to evaluate tobacco smoke exposure. The LFIA uses a competitive assay format where the COT-BSA capture competes with the target COT in urine samples for binding to the monoclonal antibody against COT (mAb-COT) conjugated with gold nanoparticles (mAb-COT-AuNPs). To improve the sensitivity and selectivity of the LFIA-COT, we focused on optimizing the diameter of AuNPs, the conjugation of mAb-COT, and the concentration of the COT-BSA capture. Our findings reveal that the utilization of 40 nm AuNPs in conjugation with a concentration of 4 mg mL-1 of mAb-COT demonstrated significantly greater efficacy compared to LFAs utilizing 20 nm AuNPs. Under the optimal conditions, the LFIA-COT demonstrated sensitive detection of COT at a level of 150 ng mL-1 within 15 min, as observed by the naked eye. It possesses a linear range of 25 to 200 ng mL-1 of COT, with the limit of detection (LOD) of 11.94 ng mL-1 in human urine samples when the color intensity is analyzed using ImageJ software. Our LFIA described here is simple and requires less time for COT detection. It can be used for the rapid and quantitative detection of COT in urine samples in clinical settings.

Structure-based epitope prediction and assessment of cross-reactivity of Myrmecia pilosula venom-specific IgE and recombinant Sol g proteins (Solenopsis geminata).

The global distribution of tropical fire ants (Solenopsis geminata) raises concerns about anaphylaxis and serious medical issues in numerous countries. This investigation focused on the cross-reactivity of allergen-specific IgE antibodies between S. geminata and Myrmecia pilosula (Jack Jumper ant) venom proteins due to the potential emergence of cross-reactive allergies in the future. Antibody epitope analysis unveiled one predominant conformational epitope on Sol g 1.1 (PI score of 0.989), followed by Sol g 2.2, Sol g 4.1, and Sol g 3.1. Additionally, Pilosulin 1 showed high allergenic potential (PI score of 0.94), with Pilosulin 5a (PI score of 0.797) leading in B-cell epitopes. The sequence analysis indicated that Sol g 2.2 and Sol g 4.1 pose a high risk of cross-reactivity with Pilosulins 4.1a and 5a. Furthermore, the cross-reactivity of recombinant Sol g proteins with M. pilosula-specific IgE antibodies from 41 patients revealed high cross-reactivity for r-Sol g 3.1 (58.53%) and r-Sol g 4.1 (43.90%), followed by r-Sol g 2.2 (26.82%), and r-Sol g 1.1 (9.75%). Therefore, this study demonstrates cross-reactivity (85.36%) between S. geminata and M. pilosula, highlighting the allergenic risk. Understanding these reactions is vital for the prevention of severe allergic reactions, especially in individuals with pre-existing Jumper Jack ant allergy, informing future management strategies.

Protein-Ligand Binding and Structural Modelling Studies of Pheromone-Binding Protein-like Sol g 2.1 from Solenopsis geminata Fire Ant Venom.

Sol g 2 is the major protein in Solenopsis geminata fire ant venom. It shares the highest sequence identity with Sol i 2 (S. invicta) and shares high structural homology with LmaPBP (pheromone-binding protein (PBP) from the cockroach Leucophaea maderae). We examined the specific Sol g 2 protein ligands from fire ant venom. The results revealed that the protein naturally formed complexes with hydrocarbons, including decane, undecane, dodecane, and tridecane, in aqueous venom solutions. Decane showed the highest affinity binding (Kd) with the recombinant Sol g 2.1 protein (rSol g 2.1). Surprisingly, the mixture of alkanes exhibited a higher binding affinity with the rSol g 2.1 protein compared to a single one, which is related to molecular docking simulations, revealing allosteric binding sites in the Sol g 2.1 protein model. In the trail-following bioassay, we observed that a mixture of the protein sol g 2.1 and hydrocarbons elicited S. geminata worker ants to follow trails for a longer time and distance compared to a mixture containing only hydrocarbons. This suggests that Sol g 2.1 protein may delay the evaporation of the hydrocarbons. Interestingly, the piperidine alkaloids extracted have the highest attraction to the ants. Therefore, the mixture of hydrocarbons and piperidines had a synergistic effect on the trail-following of ants when both were added to the protein.

Proteomic analysis of crocodile white blood cells reveals insights into the mechanism of the innate immune system.

Crocodiles have a particularly powerful innate immune system because their blood contains high levels of antimicrobial peptides. They can survive injuries that would be fatal to other animals, and they are rarely afflicted with diseases. To better understand the crocodile's innate immune response, proteomic analysis was performed on the white blood cells (WBC) of an Aeromonas hydrophila-infected crocodile. Levels of WBC and red blood cells (RBC) rapidly increased within 1 h. In WBC, there were 109 up-regulated differentially expressed proteins (DEP) that were up-regulated. Fifty-nine DEPs dramatically increased expression from 1 h after inoculation, whereas 50 up-regulated DEPs rose after 24 h. The most abundant DEPs mainly had two biological functions, 1) gene expression regulators, for example, zinc finger proteins and histone H1 family, and 2) cell mechanical forces such as actin cytoskeleton proteins and microtubule-binding proteins. This finding illustrates the characteristic effective innate immune response mechanism of crocodiles that might occur via boosted transcription machinery proteins to accelerate cytoskeletal protein production for induction of phagocytosis, along with the increment of trafficking proteins to transport essential molecules for combating pathogens. The findings of this study provide new insights into the mechanisms of the crocodile's innate immune system.

Rational design of an N-terminal cysteine-containing tetrapeptide that inhibits tyrosinase and evaluation of its mechanism of action.

There has been a resurgence of interest in bioactive peptides as therapeutic agents. This is particularly interesting for tyrosinase, which can be inhibited by thiol-containing peptides. This work demonstrates that an N-terminal cysteine-containing tetrapeptide can be rationally designed to inhibit tyrosinase activity in vitro and in cells. The tetrapeptide cysteine (C), arginine (R), asparagine (N) and leucine (L) or CRNL is a potent inhibitor of tyrosinase activity with an IC50 value of 39.62 ± 6.21 µM, which is comparable to currently used tyrosinase inhibitors. Through structure-activity studies and computational modeling, we demonstrate the peptide interacts with the enzyme via electrostatic (R with E322), hydrogen bonding (N with N260) and hydrophobic (L with V248) intermolecular interactions and that a combination of these is required for potent activity. Moreover, copper chelating activity might be one of the mechanisms of tyrosinase inhibition by CRNL. Kinetic studies show that tetrapeptide is a competitive inhibitor with two-step irreversible inhibition. In addition, CRNL had no toxicity and could reduce melanin levels in the murine melanoma cell line (B16F1). Overall, CRNL is a very promising candidate for hyperpigmentation treatment.

Characterization and Localization of Sol g 2.1 Protein from Solenopsis geminata Fire Ant Venom in the Central Nervous System of Injected Crickets (Acheta domestica).

Solenopsis geminata is recognized for containing the allergenic proteins Sol g 1, 2, 3, and 4 in its venom. Remarkably, Sol g 2.1 exhibits hydrophobic binding and has a high sequence identity (83.05%) with Sol i 2 from S. invicta. Notably, Sol g 2.1 acts as a mediator, causing paralysis in crickets. Given its structural resemblance and biological function, Sol g 2.1 may play a key role in transporting hydrophobic potent compounds, which induce paralysis by releasing the compounds through the insect's nervous system. To investigate this further, we constructed and characterized the recombinant Sol g 2.1 protein (rSol g 2.1), identified with LC-MS/MS. Circular dichroism spectroscopy was performed to reveal the structural features of the rSol g 2.1 protein. Furthermore, after treating crickets with S. geminata venom, immunofluorescence and immunoblotting results revealed that the Sol g 2.1 protein primarily localizes to the neuronal cell membrane of the brain and thoracic ganglia, with distribution areas related to octopaminergic neuron cell patterns. Based on protein-protein interaction predictions, we found that the Sol g 2.1 protein can interact with octopamine receptors (OctRs) in neuronal cell membranes, potentially mediating Sol g 2.1's localization within cricket central nervous systems. Here, we suggest that Sol g 2.1 may enhance paralysis in crickets by acting as carriers of active molecules and releasing them onto target cells through pH gradients. Future research should explore the binding properties of Sol g 2.1 with ligands, considering its potential as a transporter for active molecules targeting pest nervous systems, offering innovative pest control prospects.

The effect of edible bird's nests on the expression of MHC-II and costimulatory molecules of C57BL/6 mouse splenocytes.

The glutinous nest that builds by the saliva secretion of swiftlet is recognizable as an edible bird's nest (EBN). It enriched a medicinal value and was regarded as supplementary food that exerts various beneficial health effects, especially immune boosters. This study's objective was to determine the impact of EBN on the expression of MHC-II and costimulatory molecules (CD86 and CD80) related to the initiation of T-cell activation. Both rEBN and pEBN samples were prepared with simulated gastrointestinal digestion for enhancing the bioaccessibility of bioactive compounds. Our result showed that digested EBN samples slightly influence the upregulation of MHC-II, CD86, and CD80 in gene expression of LPS-stimulated Raw 264.7 cells. The concern of endotoxin contamination in EBN samples, which may cause a false-positive result, was measured by quantitative PCR. We found that the inflammatory genes (IL-1ß and TNF-α) were not induced by EBN treatments. Moreover, cell surface protein expression in splenocytes treated with EBN was assessed using flow cytometric analysis. Digested EBN samples demonstrated their capacity to promote the elevation of MHC-II, CD86, and CD80 cell surface protein expression. Finally, the digested-EBN-treated splenocytes only exhibited a specific response in the T-cells population. Thus, EBN is a source of the bioactive compound that has been proposed to exert a role in the stimulation of both MHC-II and costimulatory molecules for TCR/pMHC-II interaction leading to T-cell activation.

Rational design and characterization of cell-selective antimicrobial peptides based on a bioactive peptide from Crocodylus siamensis hemoglobin.

Antimicrobial resistance is a growing health concern. Antimicrobial peptides are a potential solution because they bypass conventional drug resistance mechanisms. Previously, we isolated a peptide from Crocodylus siamensis hemoglobin hydrolysate, which has antimicrobial activity and identified the main peptide from this mixture (QL17). The objective of this work was to evaluate and rationally modify QL17 in order to: (1) control its mechanism of action through bacterial membrane disruption; (2) improve its antimicrobial activity; and (3) ensure it has low cytotoxicity against normal eukaryotic cells. QL17 was rationally designed using physicochemical and template-based methods. These new peptide variants were assessed for: (1) their in vitro inhibition of microbial growth, (2) their cytotoxicity against normal cells, (3) their selectivity for microbes, and (4) the mode of action against bacteria using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal microscopy. The results indicate that all designed peptides have more potent antimicrobial efficacy than QL17 and IL15 peptides. However, only the most rationally modified peptides showed strong antimicrobial activity and minimal toxicity against normal cells. In particular, IL15.3 (hydrophobicity of 47% and net charge of + 6) was a potent antimicrobial agent (MIC = 4-12 µg/mL; MBC = 6-25 µg/mL) and displayed excellent selectivity for microbes (cf. human cells) via FACS assays. Microscopy confirmed that IL15.3 acts against bacteria by disrupting the cell membrane integrity and penetrating into the membrane. This causes the release of intracellular content into the outer environment leading to the death of bacteria. Moreover, IL15.3 can also interact with DNA suggesting it could have dual mode of action. Overall, a novel variant of QL17 is described that increases antimicrobial activity by over 1000-fold (~ 5 µg/mL MIC) and has minimal cytotoxicity. It may have applications in clinical use to treat and safeguard against bacteria.

Computational model for lipid binding regions in phospholipase (Ves a 1) from Vespa venom.

The Thai banded tiger wasp (Vespa affinis) is a dangerous vespid species found in Southeast Asia, and its stings often result in fatalities due to the presence of lethal phospholipase A[Formula: see text], known as Vespapase or Ves a 1. Developing anti-venoms for Ves a 1 using chemical drugs, such as chemical drug guide, remains a challenging task. In this study, we screened 2056 drugs against the opening conformation of the venom using the ZINC 15 and e-Drug 3D databases. The binding free energy of the top five drug candidates complexed with Ves a 1 was calculated using 300-ns-MD trajectories. Our results revealed that voxilaprevir had a higher binding free energy at the catalytic sites than other drug candidates. Furthermore, the MD simulation results indicated that voxilaprevir formed stable conformations within the catalytic pocket. Consequently, voxilaprevir could act as a potent inhibitor, opening up avenues for the development of more effective anti-venom therapeutics for Ves a 1.

Electrochemical biosensor based on cellulose nanofibers/graphene oxide and acetylcholinesterase for the detection of chlorpyrifos pesticide in water and fruit juice.

In this work, cellulose nanofibers and graphene oxide are used to fabricate a simple and reliable electrochemical biosensor, based on acetylcholinesterase (AChE) for the detection of highly dangerous organophosphates (OPs), utilizing chlorpyrifos as a representative sample. AChE is an enzyme that is essential for neurotransmission and catalyzes the conversion of acetylcholine (ATCh) into thiocholine and acetic acid. The pesticide used in this work, chlorpyrifos, inhibits the catalytic activity of AChE on ATCh, and this inhibition can be measured using square wave voltammetry (SWV). Utilizing a process of surface modification, layers of cellulose nanofibers, graphene oxide, a chitosan-graphene oxide composite, and acetylcholinesterase (AChE/CS-GO/GO/CNFs) were immobilized on a screen-printed carbon electrode (SPCE). The modified SPCE working electrode was characterized using scanning electron microscopy and graphene oxide trapped in the cellulose nanofibers was found to increase the sensitivity of the biosensor. The modified biosensor demonstrated good performance for detection of chlorpyrifos over a linear range of 25-1000 nM under optimum conditions, and the limits of detection and quantification were 2.2 nM and 73 nM, respectively. Our sophisticated technique might offer a more precise, straightforward, quick, and environmentally friendly way to assess chlorpyrifos contamination in water and juice samples.

Rational Design of RN15m4 Cathelin Domain-Based Peptides from Siamese Crocodile Cathelicidin Improves Antimicrobial Activity.

Antimicrobial peptides are becoming a new generation of antibiotics due to their therapeutic potential and ability to decrease drug-resistant bacteria development. Cathelicidins are known as effective peptides of vertebrate immunity that play crucial roles in the defensive strategy against pathogens. To improve its potency, the RN15 antibacterial peptide derived from the cathelin domain of Crocodylus siamensis cathelicidin has been modified and its antimicrobial properties investigated. Peptides were derived by template-based and physicochemical designation. The RN15 derivative peptides were predicted through their structure modeling, antimicrobial potency, and peptide-membrane calculation. The antimicrobial and cytotoxic activities of candidate peptides were investigated. Simultaneous consideration of physicochemical characteristics, secondary structure modeling, and the result of antimicrobial peptide tools prediction indicated that RN15m4 peptide was a candidate derivative antimicrobial peptide. The RN15m4 peptide expresses antimicrobial activity against most Gram-positive and Gram-negative bacteria and fungi with a lower minimum inhibition concentration (MIC) than the parent peptide. Besides, the time-killing assay shows that the designed peptide performed its ability to quickly kill bacteria better than the original peptide. Scanning electron microscopy (SEM) displayed the destruction of the bacterial cell membrane caused by the RN15m4 peptide. In addition, the RN15m4 peptide exhibits low hemolytic activity and low cytotoxic activity as good as the template peptide. The RN15m4 peptide performs a range of antimicrobial activities with low cell toxicity. Our study has illustrated the combination approach to peptide design for potent antibiotic peptide discovery.

Unveiling the Potent Antiviral and Antioxidant Activities of an Aqueous Extract from Caesalpinia mimosoides Lamk: Cheminformatics and Molecular Docking Approaches.

Our group previously demonstrated that Caesalpinia mimosoides Lamk exhibits many profound biological properties, including anticancer, antibacterial, and antioxidant activities. However, its antiviral activity has not yet been investigated. Here, the aqueous extract of C. mimosoides was prepared from the aerial parts (leaves, stalks, and trunks) to see whether it exerts anti-influenza (H1N1) effects and to reduce the organic solvents consumed during extraction, making it a desirable approach for the large-scale production for medical uses. Our plant extract was quantified to contain 7 g of gallic acid (GA) per 100 g of a dry sample, as determined using HPLC analysis. It also exerts potent antioxidant activities comparable to those of authentic GA. According to untargeted metabolomics (UPLC-ESI(-)-QTOF-MS/MS) with the aid of cheminformatics tools (MetFrag (version 2.1), SIRIUS (version 5.8.3), CSI:FingerID (version 4.8), and CANOPUS), the major metabolite was best annotated as "gallic acid", phenolics (e.g., quinic acid, shikimic acid, and protocatechuic acid), sugar derivatives, and dicarboxylic acids were deduced from this plant species for the first time. The aqueous plant extract efficiently inhibited an influenza A (H1N1) virus infection of MDCK cells with an IC50 of 5.14 µg/mL. Of equal importance, hemolytic activity was absent for this plant extract, signifying its applicability as a safe antiviral agent. Molecular docking suggested that GA interacts with conserved residues (e.g., Arg152 and Asp151) located in the catalytic inner shell of the viral neuraminidase (NA), sharing the same pocket as those of anti-neuraminidase drugs, such as laninamivir and oseltamivir. Additionally, other metabolites were also found to potentially interact with the active site and the hydrophobic 430-cavity of the viral surface protein, suggesting a possibly synergistic effect of various phytochemicals. Therefore, the C. mimosoides aqueous extract may be a good candidate for coping with increasing influenza virus resistance to existing antivirals.

TA-AgNPs/Alginate Hydrogel and Its Potential Application as a Promising Antibiofilm Material against Polymicrobial Wound Biofilms Using a Unique Biofilm Flow Model.

The presence of biofilm within a chronic wound may delay the healing process. Thus, control of biofilm formation and providing bactericidal effect are crucial factors for wound healing management. Alginate-based nanocomposite hydrogels have been suggested as dressing materials for wound treatment, which are employed as a biocompatible matrix. Therefore, in this study, we aimed to develop a biocompatible antimicrobial wound dressing containing AgNPs and demonstrate its efficacy against polymicrobial wound biofilms by using a biofilm flow device to simulate a chronic infected, exuding wound and specific wound environment. The results from agar well diffusion, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays showed that TA-AgNPs exhibited antibacterial activity against wound pathogens. Additionally, the Minimum Biofilm Eradication Concentration assay (MBEC) demonstrated it could impair biofilm formation. Importantly, our TA-AgNPs/Alginate hydrogel clearly showed antibacterial activities against Streptococcus pyogenes, Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, we used the biofilm flow device to test the topical antimicrobial hydrogel against a three-species biofilm. We found that TA-AgNPs/Alginate hydrogel significantly showed a 3-4 log reduction in bacterial numbers when applied with multiple doses at 24 h intervals, and was especially effective against the chronic wound pathogen P. aeruginosa. This work highlighted that the TA-AgNPs/Alginate hydrogel is a promising material for treating complex wound biofilms.

Polydopamine Nanoparticles Functionalized Electrochemical DNA Aptasensor for Serum Glycated Albumin Detection.

Polydopamine (PDA) has now been widely applied to electrochemical biosensing because of its excellent biocompatibility, abundant functional groups, and facile preparation. In this study, polydopamine nanoparticles (PDA-NPs)-functionalized electrochemical aptasensor was developed for the rapid, sensitive, and cost-effective detection of glycated albumin (GA), a promising biomarker for glycemic control in diabetic patients. PDA-NPs were synthesized at various pH conditions in Tris buffer. Cyclic voltammetry (CV) of PDA-NPs-coated screen-printed carbon electrodes (SPCEs) revealed that the materials were more conductive when PDA-NPs were synthesized at pH 9.5 and 10.5 than that at pH 8.5. At pH 10.5, the prepared PDA and PDA-aptamer NPs were monodispersed spherical morphology with an average size of 118.0 ± 1.9 and 127.8 ± 2.0 nm, respectively. When CV and electrochemical impedance spectrometry (EIS) were used for the characterization and detection of the electrochemical aptasensor under optimal conditions, the proposed aptasensor exhibited a broad linearity for detection of GA at a clinically relevant range of (1-10,000 µg mL-1), provided a low detection limit of 0.40 µg mL-1, appreciable reproducibility (less than 10%), and practicality (recoveries 90-104%). In addition, our developed aptasensor presented a great selectivity towards GA, compared to interfering substances commonly present in human serum, such as human serum albumin, urea, glucose, and bilirubin. Furthermore, the evaluation of the aptasensor performance against GA-spiked serum samples showed its probable applicability for clinical use. The developed PDA aptasensor demonstrated excellent sensitivity and selectivity towards GA detection with a simple and facile fabrication process. This proposed technique shows its potential application in GA measurement for improving the screening and management of diabetic patients in the future.