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Due to the instability of anthocyanins, their application as natural colorants is limited. To improve their stability, anthocyanins extracted from sour cherry were copigmented with tannic acid at varying molar ratios. The optimal anthocyanin:copigment molar ratio was determined to be 1:0.25. Subsequently, both non-copigmented and copigmented anthocyanins (using the optimal tannic acid molarity) were spray-dried with either maltodextrin alone (T1 and T2) or a combination of maltodextrin and Persian gum (T3 and T4). The anthocyanin retention in T2 and T4 was approximately 53 % and 38 %, respectively, which were higher than in the non-copigmented samples. All powders demonstrated high encapsulation efficiency (>90.37 %). Stability tests on the anthocyanins conducted over 28 days indicated that light exposure had no effect on the reduction of anthocyanin content when maltodextrin was used. Thus, the copigmentation of anthocyanins with tannic acid, combined with encapsulation in maltodextrin, presents a promising method for producing a stable natural colorant.
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Antocianinas , Cápsulas , Polissacarídeos , Taninos , Polissacarídeos/química , Antocianinas/química , Taninos/química , Cápsulas/química , Prunus avium/química , Extratos Vegetais/química , Composição de Medicamentos , PolifenóisRESUMO
The quest for scarless wound healing is imperative in healthcare, aiming to diminish the challenges of conventional wound treatment. Hyaluronic acid (HA), a key component of the skin's extracellular matrix, plays a pivotal role in wound healing and skin rejuvenation. Leveraging the advantages of HA hydrogels, this research focuses first on tuning the physicochemical and mechanical properties of photo-crosslinkable methacrylated HA (MAHA) by varying the methacrylation degree, polymer concentration, photo-crosslinker concentration, and UV exposure time. The optimized hydrogel, featuring suitable porosity, swelling ratio, degradability, and mechanical properties, was then used for the combined delivery of tannic acid (TA), known for its hemostatic, antibacterial, and antioxidant properties, and Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) cultured on the MAHA-TA hydrogel to enhance skin regeneration. The composite MAHA-TA-MSC hydrogel demonstrated favorable pores and biocompatibility, evidenced by cell viability, and promoted cell proliferation. When applied to dorsal wounds in rats, this composite hydrogel accelerated wound healing and reduced scarring. Additionally, molecular and histopathological analyses revealed increased expression of IL-10, the TGF-ß3/TGF-ß1 ratio, and the Collagen III/Collagen I ratio. These findings suggest that the MAHA-TA-MSC hydrogel is a promising candidate for scarless acute wound healing.
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As a battery-type anode material for sodium ion capacitors (SICs), titanate (H2Ti2O5·H2O, HTO) exhibits good rate capability due to its layered structure, easy to insert Na+ ions and low potential during sodium-ion storage. However, the structure is unstable due to the lattice distortion resulting from the irreversible embedment of Na+ in the process of sodium storage. So there is a significant mismatch between the dynamic reaction of the HTO anode and the capacitive cathode. Surface coating engineering is a useful strategy for stabilizing the HTO structure, which is critical for improving the kinetic response. In this work, a surface coating technique is designed to enhance the surface of HTO nanoarrays on titanium foil by using the oligomers of tannic acid formaldehyde polymer (TAF) chelated Bi3+ ions (Bi-TAF). As a binder-free anode, HTO coated with Bi-TAF (HTO@Bi-TAF) exhibits more excellent capacity (335.2 mA h g-1, 0.1 A g-1), rate capability (212.3 mA h g-1, 2.0 A g-1), and cycle stability (97 % capacity maintenance following 2000 cycles at 1.0 A g-1) than HTO and HTO coated with TAF (HTO@TAF). At the sweep rate of 1.0 mV s-1, the kinetic investigation reveals that the capacitance contribution of HTO@Bi-TAF is 86 %. The SICs exhibit a significant energy/power density (89.4 Wh kg-1/250 W kg-1). This work shows that the Bi-TAF polymer coating has a dual effect of rate capability improvement and structural protection on the prepared HTO. This results in a reasonable and effective surface coating strategy that provides outstanding rate capability and extended cycle performance of titanium-based anode materials for SICs.
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Natural compound-based treatments provide innovative ways for ulcerative colitis therapy. However, poor targeting and rapid degradation curtail its application, which needs to be addressed. Inspired by biomacromolecule-based materials, we have developed an orally administrated nanoparticle (GBP@HA NPs) using bovine serum albumin as a carrier for polyphenol delivery. The system synergizes galactosylated bovine serum albumin with two polyphenols, epigallocatechin gallate and tannic acid, which is then encased in "nanoarmor" of ε-Polylysine and hyaluronic acid to boost its stability and targeting. Remarkably, the nanoarmor demonstrated profound therapeutic effects in both acute and chronic mouse models of ulcerative colitis, mitigating disease symptoms via multiple mechanisms, regulating inflammation related factors and exerting a modulatory impact on gut microbiota. Further mechanistic investigations indicate that GBP@HA NPs may act through several pathways, including modulation of Keap1-Nrf2 and NF-κB signaling, as well as Caspase-1-dependent pyroptosis. Consequently, this novel armored nanotherapy promotes the way for enhanced polyphenol utilization in ulcerative colitis treatment research.
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Colite Ulcerativa , Ácido Hialurônico , Nanopartículas , Colite Ulcerativa/tratamento farmacológico , Animais , Ácido Hialurônico/química , Camundongos , Nanopartículas/química , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Soroalbumina Bovina/química , Polilisina/química , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Catequina/uso terapêutico , Polifenóis/química , Polifenóis/farmacologia , Masculino , Taninos/química , Taninos/farmacologia , Taninos/uso terapêutico , Portadores de Fármacos/química , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
The search for synergies between natural products and commercial antibiotics is a promising strategy against bacterial resistance. This study determined the antimicrobial capacity of Nerol (NE) and Tannic Acid (TA) against 14 pathogenic bacteria, including ESKAPE pathogens. TA exhibited the lowest Minimum Inhibitory Concentrations (MICs) at 162.5 µg/mL against Pasteurella aerogenes and 187.5 µg/mL against Acinetobacter baumannii (WHO priority 1). NE showed its lowest MIC of 500 µg/mL against both Pasteurella aerogenes and Salmonella enterica. A total of 35 combinations of NE and 13 of TA with eight commercial antibiotics were analyzed. For NE, combinations with Streptomycin and Gentamicin were effective against Salmonella enterica, Bacillus subtilis, and Streptococcus agalactiae, with antibiotic MIC reductions between 75.0 and 87.5%. TA showed six synergies with Chloramphenicol, Ampicillin, Erythromycin, and Streptomycin against Acinetobacter baumannii, Streptococcus agalactiae, and Pasteurella aerogenes, with MIC reductions between 75.0 and 93.7%. Additionally, 31 additive effects with antibiotics for NE and 8 for TA were found. Kinetic studies on these synergies showed complete inhibition of bacterial growth, suggesting that natural products enhance antibiotics by facilitating their access to targets or preventing resistance. Given their safety profiles recognized by the EPA and FDA, these natural products could be promising candidates as antibiotic enhancers.
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A novel photothermal immunochromatographic test strip (PITS) with tannic acid (TA) modified cobalt sulfide (CoS) nanospheres (CoS@TA) as immuno-probe element was developed for the detection of aflatoxin B1 (AFB1). CoS nanospheres (CoS NPs) with excellent photothermal conversion efficiency (η = 47.5 %) was synthesized and skillfully chelated with TA to improve its dispersion, biocompatibility, and chromatographic properties. After modification, the CoS@TA coupled with monoclonal antibody (mAb) against AFB1 (CoS@TA-mAb) by simple physical adsorption. The CoS@TA based PITS achieved highly sensitive detection of AFB1 with the limit of detection in photothermal signal (photothermal-LOD) of 0.00503 µg/L, which was 19.88-fold higher than the LOD in visual signal (visual-LOD, 0.1 µg/L). The application of TA in the modification of CoS provided ideas to improve the properties of functional nanomaterials such as dispersion and biocompatibility, and the application of CoS@TA in PITS construction laid a methodological foundation for further improving the detection sensitivity of trace targets.
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Recently, layered double hydroxides (LDH) have shown great potential in photoreduction of CO2 owing to its flexible structural adjustability. In this study, the mild acidic property of tannic acid (TA) is exploited to etch the bimetal LDH to create abundant vacancies to gain the coordination unsaturated active centers. Based on the different chelating abilities of TA to various metal ions, the active metals are remained by selective chelation while the inert metals are removed during the etching process of bimetal LDH. Furthermore, selective chelating with metal ions not only increases the percentage of highly active metals but also compensates for the structural damage caused by the etch, which achieves a scalpel-like selective construction of vacancies. The NiAl-LDH etched and functionalized by TA for 3 h exhibits superior photo-reduction of CO2 performance without co-catalysts and photo-sensitizers, which is 14 times that of the pristine NiAl-LDH. The fact that many bimetal LDHs can be functionalized by TA and exhibit significantly improved photocatalytic efficiency is confirmed, suggesting this strategy is generalized to functionalize double- or multi-metal LDH. The method provided in this work opens the door for polyphenol-functionalized LDHs to enhance their ability for light-driven chemical transformations.
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Tannic acid is widely regarded as one of the most promising natural polyphenolic compounds. However, current research predominantly focuses on the utilization of its phenolic hydroxyl groups, with limited exploration of the functional potential of its aromatic structure. Herein, one-dimensional nanofibers based on supramolecular self-assembly were successfully prepared through the simple alkylation reaction of tannic acid and the π-π stacking of aromatic structures. These fibers, with lengths reaching tens of micrometers and an average height of 10 nm, were clearly observed using SEM and AFM. A film with excellent electrical conductivity (σ = 37.9 µS/cm) was fabricated by vacuum filtering the organic suspension of these fibers, which was 100-fold higher than that of the TA film. Additionally, the hydrophobic and lipophilic properties of Bn-TA were further investigated through oil-water separation experiments, where the Bn-TA membrane displayed excellent separation efficiency and durability, maintaining stable performance over multiple cycles. This strategy presents opportunities for the high-value utilization of tannic acid.
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The electrochemical performances of Ti3C2Tx MXene are severely restricted by the easy oxidation and restacking. Herein, tannic acid (TA) is introduced into Ti3C2Tx dispersion, and the mixed dispersion is further subjected to a simple hydrothermal treatment to prepare the hydrothermal Ti3C2Tx and TA composite (h-Ti3C2Tx@h-TA). Due to the decomposition of TA into gallic acid (GA), hydrothermal TA (h-TA) is a mixture of TA and GA. The strong interaction between h-TA and MXene mainly involves chemical interaction between the hydroxyl groups in h-TA and the surface/edge Ti atoms, along with numerous hydrogen bonds. The h-TA intercalation weakens MXene restacking and increases interlayer spacing, thereby improving ion transport pathways and accessibility. The chemical interaction between the hydroxyl groups of GA and the Ti atoms significantly enhances oxidation resistance and pseudocapacitive active sites. Therefore, the h-Ti3C2Tx@h-TA film electrode shows significantly enhanced capacitance (848 F·g-1 at 1 A g-1) and cycling stability (100% retention after 20 000 cycles). Moreover, flexible sandwiched supercapacitors with symmetrical h-Ti3C2Tx@h-TA electrodes exhibit a high energy density of 30.1 Wh kg-1 at a high power density of 300 W kg-1, outperforming those of Ti3C2Tx-based film electrodes and sandwiched supercapacitors reported so far. The extrusion-printed microsupercapacitors with h-Ti3C2Tx@h-TA electrodes demonstrate high areal capacitance (135 mF cm-2 at 5 mV s-1) along with energy storage performance (6.74 µWh cm-2 at 506 µW cm-2) and cycling stability (98.8% retention after 41 460 cycles), all while maintaining excellent flexibility. These impressive results indicate the great application potential of the hydrothermal Ti3C2Tx MXene and tannic acid composite in flexible energy storage devices.
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Chloramphenicol (CAP), a potent antibiotic capable of inhibiting protein synthesis, presents significant challenges related to long-term dosing and its persistent leaching into the environment, raising concerns about environmental contamination and resistance development. To address this issue, we developed a reliable, low-cost, and biocompatible nanocomposite material comprising tannic acid (TA)-reduced graphene oxide (rGO) intercalated into manganese-doped tin oxide nanoparticles (MnSnO2 NPs). The structural formation and catalytic activity of the MnSnO2 NPs/TA-rGO nanocomposite were characterized using field emission-scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. This material exhibits robust interfacial interactions and synergistic effects, resulting in an admirable electrocatalytic reduction response for CAP sensing. The presence of co-interference molecules improved the selectivity performance of the MnSnO2 NPs/TA-rGO-modified glassy carbon electrode. The fabricated exhibited a two linear determination range (0.011-103.43 µmol L-1 and 103.43-1924.16 µmol L-1), with a detection limit (LOD) is 6.7 nmol L-1 and limit of quantification (LOQ) is 12.3 nmol L-1. Furthermore, this sensor demonstrated good sensitivity, admirable reproducibility, repeatability, and storage stability. Finally, the practicability of the fabricated MnSnO2 NPs/TA-rGO glassy carbon electrode sensor was evaluated by analyzing the CAP content in milk, honey, eye drops, biofluids (human serum and urine), and river water, and satisfactory recovery rates of 95.4 %-100.3 % were noted.
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A nanocomposite of tannic acid and cellulose nanowhiskers (CNW)-reinforced polysulfone (PSF) was used to develop a metallochromic nanofibrous membrane sensor for iron(III) in aqueous media. Tannic acid was used as an active detecting probe, whereas the CNW@PSF composite was employed as a hosting material. Cellulose nanowhiskers (7-12 nm) were obtained from microcrystalline cellulose (MCC). According to the coloration parameters, a bathochromic shift from colorless (415 nm) to purple (561 nm) occurs when ferric cations bind to the phenolic hydroxyls of the tannic acid probe. The concentration of ferric was found to be directly correlated to the extent of the color change, demonstrating a detection limit of 0.1-250 ppm. This could be attributed to the creation of a coordinative complex between ferric ions and phenolic tannic acid. The generated nanofibers were inspected by energy-dispersive X-ray (EDX) and scanning electron microscopy (SEM). The electrospun nanofibrous membrane showed an average diameter between 75 and 150 nm. The tannic acid-containing nanofibers are remarkably reusable and simple. The tannic acid-encapsulated polysulfone nanofibrous membrane was used to detect various metal ions, demonstrating a high selectivity for Fe3+. The ideal pH range for the identification of Fe3+ was determined to be in the range of 4.25-6.75.
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Natural photosynthetic systems require spatiotemporal organization to optimize photosensitized reactions and maintain overall efficiency, involving the hierarchical self-assembly of photosynthetic components and their stabilization through synergistic interactions. However, replicating this level of organization is challenging due to the difficulty in efficiently communicating supramolecular nano-assemblies with nanoparticles or biological architectures, owing to their dynamic instability. Herein, we demonstrate that the supramolecular reconstruction of self-assembled amphiphilic rhodamine B nanospheres (RN) through treatment with metal-phenolic coordination complexes results in the formation of a stable hybrid structure. This reconstructed structure enhances electron transfer efficiency, leading to improved photocatalytic performance. Due to the photoluminescence quenching property of RN and its electronic synergy with tannic acid (T) and zirconium (Z), the supramolecular complexes of hybrid nanospheres (RNTxZy) with Pt nanoparticles or a biological workhorse, Shewanella oneidensis MR-1, showed marked improvement in photocatalytic hydrogen production. The supramolecular hybrid particles with a metal-phenolic coordination layer showed 5.6- and 4.0-fold increases, respectively, in the productivities of hydrogen evolution catalyzed by Pt (Pt/RNTxZy) and MR-1 (M/RNTxZy), respectively. These results highlight the potential for further advancements in the structural and photochemical control of supramolecular nanomaterials for energy harvesting and bio-hybrid systems.
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Rheumatoid arthritis (RA) is a chronic disease characterized by immune cell infiltration and cartilage damage. The local lesion of RA shows severe oxidative stress and proinflammatory cytokine secretion. For drug therapy, the efficacy of agents, such as methotrexate (MTX), may be greatly limited, resulting from the low bioavailability, immune clearance, and toxic side effects. A nanocarrier (TA-PBA NPs) was developed with anti-inflammatory and antioxidant activities, combined with MTX to prepare nanomedicine (MTX NPs) for synergistic treatment of RA. Moreover, inspired by the biological functions homing to inflammation lesion of macrophages, the biomimetic nanomedicine camouflaged with macrophage membrane (MM@MTX NPs) was constructed. TA-PBA NPs could timely promote MTX release in response to the overaccumulated ROS to exhibit high anti-inflammatory and antioxidant activities for alleviating RA progression. The experimental results confirmed that MM@MTX NPs could significantly reduce the secretion of proinflammatory cytokines (TNF-α) while significantly increasing the typical anti-inflammatory cytokines (IL-10), promote the phenotype transformation of macrophages from M1 to M2, and up-regulate the Nrf2-keap1 pathway-related proteins (HO-1 and NRF2) to positively regulate the local inflammation for effectively inhibiting RA development. Thus, MM@MTX NPs represent a possible candidate as a safe and efficient nanotherapy platform for RA management.
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Rationale: Alzheimer's disease (AD) is hallmarked by amyloid-ß (Aß) plaques and hyperphosphorylated tau (p-tau) neurofibrillary tangles. While Aß-centric therapies have shown promise, the complex pathology of AD requires a multifaceted therapeutic approach. The weak association between Aß levels and cognitive decline highlights the need for alternative theranostic strategies. Currently, oxidative stress and tau hyperphosphorylation are now recognized as critical pathological events in AD. Thus, therapies that concurrently attenuate oxidative stress damage and inhibit tau pathology hold great potential for AD treatment. Methods: Herein, a multifunctional neuron-targeted nanocomposite is devised to realize dual imaging-guided AD therapy, integrating the inhibition of tau pathology and reactive oxygen species (ROS)-neutralizing biofunctions. The construction of the nanocomposite incorporates polyphenolic antioxidants tannic acid (TA)-based nanoparticles carrying manganese ions (Mn2+) and fluorescent dye IR780 iodide (IR780), coupled with a neuron-specific TPL peptide. The resulting IR780-Mn@TA-TPL nanoparticles (NPs) are comprehensively evaluated in both in vitro and in vivo AD models to assess their imaging capabilities and therapeutic efficacy. Results: The nanocomposite facilitates Mn-enhanced magnetic resonance (MR) imaging and near-infrared (NIR) fluorescence imaging. It effectively neutralizes toxic ROS and reduces tau hyperphosphorylation and aggregation. In AD rat models, the nanocomposite restores neuronal density in the hippocampus and significantly improves spatial memory. Conclusions: Such a neurontargeting multifunctional nanocomposite represents a potential theranostic strategy for AD, signifying a shift towards bimodal imaging-guided treatment approaches.
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Doença de Alzheimer , Imageamento por Ressonância Magnética , Nanocompostos , Taninos , Proteínas tau , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/diagnóstico por imagem , Animais , Taninos/farmacologia , Taninos/uso terapêutico , Taninos/química , Nanocompostos/química , Imageamento por Ressonância Magnética/métodos , Proteínas tau/metabolismo , Humanos , Ratos , Modelos Animais de Doenças , Imagem Óptica/métodos , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Manganês/química , Nanomedicina Teranóstica/métodos , Terapia Combinada/métodos , PolifenóisRESUMO
Lysozyme (LZM) is an important enzyme in medicine and industry. Tannic acid (TA) is used in brewing, wine industry, and as a food flavor enhancer. In nutritional and food science, LZM interacts with TA, notably in wine and saliva. This study aimed to investigate the binding interaction between LZM and TA using surface plasmon resonance, molecular docking, and molecular dynamics simulation. Chicken egg white lysozyme (CEWLZM) was applied as a model protein. Tri-N-acetylchitotriose (NAG3), the known inhibitor of CEWLZM, was used in the redocking experiments to determine the precise binding location within the complex. The average binding energies obtained from docking NAG3 and tannic acid to the target structure of CEWLZM were found to be -6.46 ± 0.05 kcal/mol and -7.52 ± 0.39 kcal/mol, respectively. The binding free energy of the CEWLZM-TA complex was then calculated as -27.61 kcal/mol by MMPBSA based on MD simulation trajectories. The observed interactions between the ligands and the lysozyme structure were mainly driven by hydrophobic, van der Waals, and H-bond interactions formed by the active site residues. MD simulations showed consistent and satisfactory binding distances between CEWLZM and TA throughout the analysis. SPR analysis was performed using 1X PBS buffer (pH 7.4) as coupling and running buffers, 30 µL/min as flow rate, and 2.5 mg/mL CEWLZM. Serial concentrations of TA (20-150 µM) were injected through immobilized CEWLZM, and the K D value of CEWLZM-TA binding was obtained as 4.17 × 10-5 M. This study could enhance existing literature and pave the way for future research in food science and oral biology.
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Pseudomonas aeruginosa is a harmful pathogen that causes a variety of acute and chronic infections through quorum sensing (QS) mechanisms. The increasing resistance of this bacterium to numerous antibiotics has created a demand for new medications that specifically target QS. Endophytes can be the source of compounds with antibacterial properties. This research is the first to examine tannic acid (TA) produced by endophytic fungus as a potential biotherapeutic agent. A novel endophytic fungal isolate identified as Penicillium oxalicum was derived from the cladodes of Opuntia ficus-indica (L.). The species identification for this isolate was confirmed through sequencing of the internal transcribed spacer region. The metabolites from the culture of this isolate were extracted using ethyl acetate, then separated and characterized using chromatographic methods. This led to the acquisition of TA, a compound that shows strong anti-QS and excellent antibacterial effects against extensively drug-resistant P. aeruginosa strains. Furthermore, it was shown that treating P. aeruginosa with the obtained TA reduced the secretion of virulence factors controlled by QS in a dose-dependent manner, indicating that TA inhibited the QS characteristics of P. aeruginosa. Simultaneously, TA significantly inhibited the expression of genes associated with QS, including rhlR/I, lasR/I, and pqsR. In addition, in silico virtual molecular docking showed that TA could efficiently bind to QS receptor proteins. Our results showed that P. oxalicum could be a new source of TA for the treatment of infections caused by extensively drug-resistant P. aeruginosa.
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Antibacterianos , Penicillium , Pseudomonas aeruginosa , Percepção de Quorum , Taninos , Percepção de Quorum/efeitos dos fármacos , Penicillium/efeitos dos fármacos , Penicillium/patogenicidade , Penicillium/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Taninos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Virulência/efeitos dos fármacos , Simulação de Acoplamento Molecular , Fatores de Virulência , Endófitos/metabolismo , Testes de Sensibilidade Microbiana , PolifenóisRESUMO
Adsorbent materials constructed from natural macromolecular products are favored because of their wide range of sources, biodegradability, and environmental friendliness. Salecan is a novel extracellular polysaccharide with ideal physicochemical and biological activities. Here, we have designed a polymer gel through UV-initiated polymerization of [2-(Methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) in the mixture of salecan and tannic acid. Photopatterned polymerization process allowed in situ formation of gel adsorbent in a mild reaction condition with energy-efficient manner. Batch experiments for toluidine blue (TB) adsorption were carried out as a function of initial dye concentration, solution pH, contact time, and gel dosage to examine the adsorption capacity, potential mechanism, and removal efficiency. Adsorption behavior exhibited a pH-dependence pattern, which was closely related to their swelling and morphological properties. Adsorption process was in conformity to pseudo-second-order kinetic and Langmuir isotherm models, unlocking a chemical adsorption behavior and monolayer-type removal. The maximum adsorption was 490.2 mg/g, which could be considered a superiorly competing value. Additionally, the UV-gel still showed desirable recyclability and maintained the adsorption effectiveness over 95 % after five regeneration cycles. This study opened up new prospects in preparing high performance adsorbent for TB decontamination and laid the foundation for polysaccharide-based adsorption material research.
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OBJECTIVES: Oral biofilms, including pathogens such as Porphyromonas gingivalis, are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases. METHODS: Phenylboronic acid-conjugated alginate (Alg-PBA) was synthesized using a carbodiimide coupling agent. Alg-PBA was then combined with tannic acid (TA) to create an Alg-PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel's self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against P. gingivalis were thoroughly characterized. RESULTS: The Alg-PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg-PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg-PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against P. gingivalis, effectively eliminating its biofilm without compromising the viability of MG-63 cells. SIGNIFICANCE: The Alg-PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against P. gingivalis. These attributes make it superior to conventional Minocycline gel. Thus, the Alg-PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases.
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Aqueous rechargeable zinc-ion batteries (ARZBs) are promising energy storage systems (ESSs) due to lots of advantages, such as high safety, high capacity, abundant resources, and low cost. However, the tunnel-structured Mn-based cathode materials such as α, ß, and γ-MnO2, which is widely used as the cathode of ARZBs, contain a phase transition in which Mn2+ ions are eluted during the discharge reaction of Zn2+ insertion, resulting in decreasing cycle life and rate capability of the ARZBs. Here, in order to enhance the cycle life and rate capability of ARZBs by retaining eluted Mn2+ ions around the ß-MnO2 cathode during the discharge process, tannic acid (TA), a type of polyphenolic biomolecule containing rich -OH groups, is introduced as a coating material. This provides a chelating effect with the eluted Mn2+ ions and hydroxyl groups on the surface of the ß-MnO2 cathode. This study clearly shows that the TA coating improves the performance of the cathode material by using a range of analytical methods. Owing to the chelating effects of TA, TA-coated ß-MnO2 cathode shows a high discharge capacity of 268.2 mAh g-1 at the current of 100 mA g-1 and 86.8% of high capacity retention after 50 cycles. This study provides the coating agents with chelating effects to develop Zn//MnO2 battery chemistry and further improve large ESSs through high electrochemical performance.
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Maintaining the differentiated phenotype and function of primary hepatocytes in vitro and in vivo represents a distinct challenge. Our paper describes microcapsules comprised of a bioactive polymer and overcoated with an ultrathin film as a means of maintaining the function of entrapped hepatocytes for at least two weeks. We previously demonstrated that heparin (Hep)-based microcapsules improved the function of entrapped primary hepatocytes by capturing and releasing cell-secreted inductive signals, including hepatocyte growth factor (HGF). Further enhancement of hepatic function could be gained by loading exogenous HGF into microcapsules. In this study, we demonstrate that an ultrathin coating of tannic acid (TA) further enhances endogenous HGF signaling for entrapped hepatocytes and increases by 2-fold the rate of uptake of exogenous HGF by Hep microcapsules. Hepatocytes in overcoated microcapsules exhibited better function and hepatic gene expression than in capsules without a TA coating. Our study showcases the potential application of ultrathin coatings to modulate the bioactivity of microcapsules and may enable the use of encapsulated hepatocytes for modeling drug toxicity or treating liver diseases.