Use Of Tannic Acid Research Articles

Characterization of caseinate-pectin complex coacervates as a carrier for delivery and controlled-release of saffron extract

In this work, microcapsules were developed by the complex coacervation of sodium caseinate and pectin as a carrier for saffron extract. Parameters such as Zeta potential, dynamic light scattering, and microscopic techniques were investigated for their influence on the formation of these complexes. Furthermore, Fourier transform infrared (FTIR) analysis confirmed the reaction mechanism between the protein and tannic acid or saffron extract. The study revealed that core/shell and protein/polysaccharide (Pr/Ps) ratios play a role in the encapsulation efficiency (EE) and loading capacity (LC) of saffron extract, with EE and LC ranging from 48.36 to 89.38% and 1.14 to 5.55%, respectively. Thermal gravimetric analysis revealed that the degradation temperature of saffron increased significantly with microencapsulation. The use of tannic acid for hardening the microcapsules led to an increase in size from 13 μm to 27 μm. Rheological findings indicated that shear-thinning behavior in the coacervates, with cross-linking, has a minor effect on the interconnected elastic gel structures. However, cross-linking improved the microcapsules' thermal and structural properties. The increase in polymer chain length due to cross-linking and the presence of the guest molecule (saffron extract) resulted in higher rheological moduli, reflecting enhanced entanglements and correlating well with the thermal, structural, and microstructural properties of the coacervates. Kinetic release studies showed a slower release in the gastric phase compared to the intestinal phase, with the Ritger–Peppas model effectively describing saffron extract release, highlighting a dominant swelling and dissolution release mechanism. Therefore, the NaCas/HMP coacervate wall materials made saffron stable in the gastric stage and sustainably release. It in the intestinal stage, promoting excellent absorption of saffron in simulated digestion.Graphical

Enhancement of Mechanical Properties of Benign Polyvinyl Alcohol/Agar Hydrogel by Crosslinking Tannic Acid and Applying Multiple Freeze/Thaw Cycles.

Hydrogels composed of natural and synthetic polymers have considerable potential for use in diverse areas such as biomedical applications and water purification. This is primarily because of their biocompatibility, biodegradability, and low toxicity. The widespread usage of composite hydrogels is hindered by a lack of simultaneous properties, such as high strength and low swelling rate. Herein, we report the preparation of novel hydrogels composed of polyvinyl alcohol (PVA)-intercalated agar polymer networks physically crosslinked with tannic acid. The hydrogel was subjected to multiple freeze/thaw (F/T) cycles (1, 3, and 5), and it was found to exhibit the highest strength after 5 F/T cycles. After 1 F/T cycle, the tensile strength of the composite hydrogel reached 1.56 MPa with a 1.0 wt% crosslinker, whereas after 5 F/T cycles, it increased to 3.77 MPa with a reduced amount (0.75 wt%) of the crosslinker. In addition, the swelling ability decreased upon increasing the crosslinker content and number of F/T cycles. Furthermore, the hydrogel demonstrated excellent water retention and a strong ability to adhere to different substrates. We have successfully implemented an innovative approach to improve the mechanical properties of PVA-based hydrogels by combining the use of tannic acid as a cross-linking agent and multiple F/T cycles. The developed hydrogels are expected to facilitate new developments in hydrogel technology, thus impacting diverse fields such as biomedical (wound dressing and artificial cartilage).

Polyphenol-Enabled 2D Nanopatch for Enhanced Nasal Mucoadhesion and Immune Activation.

The advancement of effective nasal mucoadhesive delivery faces challenges due to rapid mucociliary clearance (MCC). Conventional studies have employed mucoadhesive materials, mainly forming spherical nanoparticles, but these offer limited adhesion to the nasal mucosa. This study hypothesizes that a 2D nanoscale structure utilizing adhesive polyphenols can provide a superior strategy for countering MCC, aligning with the planar mucosal layers. We explore the use of tannic acid (TA), a polyphenolic molecule known for its adhesive properties and ability to form complexes with biomolecules. Our study introduces an unprecedented 2D nanopatch, assembled through the interaction of TA with green fluorescent protein (GFP), and cell-penetrating peptide (CPP). This 2D nanopatch demonstrates robust adhesion to nasal mucosa and significantly enhances immunoglobulin A secretions, suggesting its potential for enhancing nasal vaccine delivery. The promise of a polyphenol-enabled adhesive 2D nanopatch signifies a pivotal shift from conventional spherical nanoparticles, opening new pathways for delivery strategies through respiratory mucoadhesion.

Producing amorphous calcium carbonate using waste Ca-rich solution generated through the bio-leaching of slag

This study presents a new method for treating waste Ca-rich solutions (WCS), from which amorphous calcium carbonate (ACC) nanoparticles, an industrial product in high demand, are produced. The distinctive feature of this method is the use of tannic acid (TA) as a surfactant, employing a CO2 bubbling method under ambient conditions. By modulating the concentration of TA, the morphology and crystallization of the generated CaCO3 nanoparticles can be effectively controlled. Experimental results reveal that with increasing TA dosage, the crystallinity of CaCO3 decreases until an amorphous phase is obtained. The crystallization of ACC in solution was completely inhibited when TA was added at a concentration of more than 1%. Therefore, the proposed method provides a new strategy for the efficient preparation of ACC from WCS.

The tannization of human tissues: A nineteenth‐century educational preservation technique at the Morgagni Museum

AbstractLodovico Brunetti (1813–1899), professor of pathological anatomy at the University of Padua and founder of the Museum of Pathological Anatomy, believed that anatomical preparations were essential for the practice and teaching of pathological anatomy. At his arrival in Padua in 1855, there were around 300 made by other professors of medicine, including some by Giovanni Battista Morgagni, preserved either in liquid or dry. These conservation methods did not satisfy Brunetti, as they drastically altered the shape of the anatomical pieces (reduced by mummification and dilated in liquid); thus, he decided to create a new method called “tannization,” for the use of tannic acid. Brunetti's new method was based on dissection and injection techniques, and it had the substantial advantage of maintaining unchanged the shape and texture of the anatomical specimens, even microscopically, as well as being not so expensive. Another important advantage consisted in the fact that the different stages of the preparation could be put into practice even at different times and at a considerable distance from each other. His specimens seemed to be mummified, but they maintained a remarkable elasticity and softness, as well as almost completely unaltered proportions. Today, the Morgagni Museum of the University of Padua still preserves several tannized preparations attributable to Brunetti and his successors. The current study aims to show the educational value of this method showing the results of Brunetti's tannization nowadays.

Tannic-acid-mediated synthesis and characterization of magnetite-gold nanoplatforms for photothermal therapy.

Aim: The design of new hybrid nanoplatforms (HNPs) through the innovative and eco-friendly use of tannic acid (TA) for the synthesis and stabilization of the nanoplatforms. Materials & methods: The size, morphology, composition and magnetic and plasmonic properties of HNPs were investigated together with their ability to generate heat under laser irradiation and the hemotoxicity to explore their potential use for biomedical applications. Results & conclusion: The use of TA allowed the synthesis of the HNPs by adopting a simple and green method. The HNPs preserved the peculiar properties of both magnetic and plasmonic nanoparticles and did not show any hemotoxic effect.

Preparation and characterization of drug-loaded, electrospun nanofiber mats formulated with zein or zein-based mixtures for wound healing applications.

Electrospun zein mats are known to have poor mechanical and water uptake properties limiting their usefulness as wound dressings.
 In this study, the effects of the solvent system used, the incorporation of the polymeric additives; polyethylene glycol 20000 (PEG20K) and polyvinylpyrrolidone K30 (PVPK30); and the crosslinking agent Tannic Acid (TA) on the mechanical and water uptake characteristics of zein – based nanofiber mats were investigated.
 The incorporation of either PEG20K or PVPK30 resulted in an improvement in water vapor sorption and a reduction in water contact-angle of the nanofiber mats. In addition, the incorporation of PEG20K and PVPK30 reduced the ultimate tensile strength, and Young’s modulus while increasing the percent elongation of the nanofiber mats. The use of tannic acid as a crosslinking agent led to an increase in the water vapor sorption, ultimate tensile strength, and Young’s modulus of the nanofiber mats.
 Mats with smaller average fiber diameter, greater ultimate tensile strength, higher Young's modulus, and greater water vapor sorption were obtained when using 80% (v/v) aqueous ethanol as a solvent system during the preparation of the nanofiber mats when compared to those produced using 60% (v/v) aqueous ethanol. In addition, using solutions with lower zein concentration resulted in mats with lower average fiber diameter, lower ultimate tensile strength and Young’s modulus, and higher percent elongation.
 Selected formulations were loaded with tetracycline hydrochloride and drug release was evaluated in bulk liquid and using Franz diffusion cells. The use of Franz diffusion cells allowed the discrimination between formulation performance as a function of composition and water uptake properties. Drug release from nanofiber mats was also confirmed by observing the formation of an inhibition zone in cultures of E. coli and S. aureus using the agar diffusion assay.
 Improved performance of zein nanofiber mats was achieved using polymeric modifiers and crosslinking with tannic acid improving their suitability for wound dressing applications.

Sustainable recovery of critical elements from seawater saltworks bitterns by integration of high selective sorbents and reactive precipitation and crystallisation: Developing the probe of concept with on-site produced chemicals and energy

The availability of raw mineral resources containing elements included in the Critical Raw Materials (CRMs) list is a growing concern for the European Union. Sea mining has been identified as a promising secondary source. In particular, brines obtained in solar saltworks (bitterns) contain relevant amounts of valuable CRMs such as Mg(II), B(III), other alkaline/alkaline earth metals (Rb(I), Cs(I), Sr(II)) and transition/post-transition elements (Co(II), Ga(III), Ge(IV)). However, the low concentration of some of these elements (µg/L) requires an effort to develop recovery routes that are sustainable and economically feasible where the required chemicals and energy are produced on-site from the saltworks bitterns (i.e. HCl and NaOH). Even the conventional recovery processes such as ion exchange, sorption and precipitation, which have proved to be competitive for metals recovery, are challenged in the case of Trace Elements (TEs). This work studies the recovery of TEs included in the CRMs list from saltworks bitterns after ion exchange processes. First, batch crystallisation and reactive precipitation were tested for some target elements in single-component solutions: Sr(II), Co(II), Ga(III), Ge(IV) and B(III). Then, the experiments were carried out with multi-component synthetic solutions assuming different scenarios of bittern streams coming out a selective extraction stage using sorption and ion exchange processes. The targeted elements were recovered except for Ge(IV), where alternative routes need to be evaluated, as its precipitation involves the use of tannic acid or sulphide solutions that could not be produced from the bitterns. However, a further concentration step would be necessary to achieve element concentrations closer to the mineral phases saturation. Moreover, model simulations were performed using the PHREEQC program, which provided a good prediction of the experimental trends obtained in most cases.

Chemical Structure of Stabilizing Layers of Negatively Charged Silver Nanoparticles as an Effector of Shifts in Soil Bacterial Microbiome under Short-Term Exposure.

In this work, we have assessed the exposure of soil bacteria from potato monoculture to three types of silver nanoparticles (AgNPs) as well as silver ions (Ag+ ions) delivered in the form of silver nitrate and a commercially available fungicide. The diversity of the soil microbial community, enzymatic activity, and carbon source utilization were evaluated. It was found that only the fungicide significantly limited the abundance and activity of soil bacteria. Silver ions significantly reduced bacterial metabolic activity. In turn, one type of AgNPs prepared with the use of tannic acid (TA) increased bacterial load and activity. There was found in all AgNPs treated soils (1) a greater proportion of all types of persistent bacteria, i.e., Bacillus, Paenibacillus, and Clostridium; (2) a visible decrease in the proportion of Nocardioides, Arthrobacter, and Candidatus Solibacter; (3) almost complete depletion of Pseudomonas; (4) increase in the number of low-frequency taxa and decrease in dominant taxa compared to the control soil. Despite the general trend of qualitative changes in the bacterial community, it was found that the differences in the chemical structure of the AgNP stabilizing layers had a significant impact on the specific metabolic activity resulting from qualitative changes in the microbiome.

Tannic Acid, as a Structural Moiety Coupled to a Protein Antigen, Exhibiting a Molecular-structure Adjuvant Activity for Antibody Specificity Enhancement

An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.

Synergy of the combined use of tannic acid extracted from the Pistacia atlantica Desf tree bark and copper as a nanocatalyst in the green synthesis of polyhydroquinolines

Synergy of the combined use of tannic acid extracted from the Pistacia atlantica Desf tree bark and copper as a nanocatalyst in the green synthesis of polyhydroquinolines

Copigmentation of Anthocyanin Extract from Parijoto Fruit (Medinilla speciosa) and Its Stability at Different Temperatures and Heating Durations

Parijoto fruit (Medinilla speciosa) has a red color and contains anthocyanins. Anthocyanins have low stability due to the effect of heating. Copigmentation can be applied to improve the stability of anthocyanins. This research aims to study the effect of the anthocyanin extract from parijoto fruit ratio and copigment on anthocyanin concentration and color stability during heating at different temperatures and durations. Anthocyanin copigmentation using tannic acid in a ratio of 1:20 and 1:40 with control without copigmentation (1:0) showed that increasing the tannic acid copigment would increase anthocyanin concentrations and reduce anthocyanin losses due to increased temperature and heating time. The use of 1:40 tannic acid copigment increased anthocyanin concentration by 38%. In addition, increasing the concentration of tannic acid increased the ability of anthocyanins to maintain color retention during heating and increased temperatures. The use of tannic acid at a ratio of 1:40 only decreased color retention by 16%, compared to control (54%) after heating at 75ºC heating for 120 minutes. Copigmentation with tannic acid up to a ratio of 1:40 was able to maintain the stability of the lightness (L*), the reddish value (a*), and the yellowish value (b*) of the anthocyanins. This study showed that this system is potential for food coloring application in the food industry.

Fabrication of Polyvinylidene Difluoride Membrane with Enhanced Pore and Filtration Properties by Using Tannic Acid as an Additive.

Potential use of tannic acid (TA) as an additive for fabrication of polyvinylidene difluoride (PVDF) membrane was investigated. The TA was introduced by blending into the dope solution with varying concentrations of 0, 1, 1.5, and 2 wt%. The prepared membranes were characterized and evaluated for filtration of humic acid (HA) solution. The stability of the membrane under harsh treatment was also evaluated by one-week exposure to acid and alkaline conditions. The results show that TA loadings enhanced the resulting membrane properties. It increased the bulk porosity, water uptake, and hydrophilicity, which translated into improved clean water flux from 15.4 L/m2.h for the pristine PVDF membrane up to 3.3× for the TA-modified membranes with the 2 wt% TA loading. The flux recovery ratio (FRR) of the TA-modified membranes (FRRs = 78–83%) was higher than the pristine one (FRR = 58.54%), with suitable chemical stability too. The improved antifouling property for the TA-modified membranes was attributed to their enhanced hydrophilicity thanks to improved morphology and residual TA in the membrane matric.

Tannic Acid for Simple and Highly Selective Visual Detection of Iron (II) and (III) Ions from Different Aqueous Environments

Tannic acid (TA) was employed as a novel colorimetric iron ion sensor. TA showed highly selective recognition for only Fe2+ and Fe3+ among a range of tested metal ions such as Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Hg2+, and Pb2+. In the presence of these metal cation solutions, only Fe2+ and Fe3+ solutions underwent impressive color change detectable with the naked eye from colorless to purple and gray, respectively. Surprisingly, TA behaves as a highly selective sensor upon chemical oxidation of iron (Fe2+ and Fe3+) cations. In addition, various sensor applications of TA were performed. For this, TA-impregnated silica gel, alumina oxide sheet, and filter paper were used. Each test strip showed very high selectivity for iron ions. The detection limit of the sensor for Fe2+ and Fe3+ was found to be 1.0 × 10−6 M, and the association constant Ka was determined as 4.05 × 104 M−1 and 1.80 × 107 M−1. The order of ion binding power was determined to be Fe3+ > Fe2+ by UV-Vis spectroscopy. These discernable color changes due to the complexion of TA with Fe2+ and Fe3+ demonstrated the utilization of TA to selectively detect these metal cations. The use of tannic acid as a complexing agent that can detect Fe (II) and Fe (III) metal ions in environmental waters by colorimetry and spectrophotometry.

Filament-anchored hydrogel layer on polypropylene hernia mesh with robust anti-inflammatory effects

The efficacy of implanted polypropylene (PP) hernia meshes is often compromised by an inflammatory response. Thus, engineering an anti-inflammatory mesh has significant implications for hernioplasty. Here, we report a facile strategy to develop a filament-anchored hydrogel layer (FAHL) on PP mesh (FAHL-P). The network of FAHL, made up of chondroitin sulfate and gelatin (CG), provided a biomimetic surface with immunoregulatory properties. The use of tannic acid (TA) as a crosslinker for CG additionally enhanced its anti-inflammatory properties. In addition, the fabrication protocol ensured that the hydrogel maintained the properties of the knitted mesh and the firmly adherent FAHL during general handling (dry state) and in the simulated body environment (wet state). CG/TA-PP killed 99.99% of S. aureus and retained 73% of its original antioxidant properties after 7 d. The FAHL durably performed with a controlled release of TA for 15 d. The strong anti-inflammatory effects of FAHL-P reduced collagen deposition and increased vascularization, which promoted native tissue generation. The fabrication strategy has potential applications in hernioplasty and may provide new insights into the design of other anti-inflammatory implants. Statement of significanceA hydrogel layer with robust anti-inflammatory effects was anchored firmly on mesh filament for hernia repair. Requiring no drug loading, this chondroitin sulphate -gelatin (CG) based hydrogel itself could inhibit the immunological attack owing to the biomimetic microenvironment created by the CG. Moreover, the hydrogel's crosslinker (tannic acid) content served as an effective scavenger for reducing pro-inflammatory factors, significantly mitigating the inflammation. Interestingly, the antibacterial effect of such hydrogel layer was also observed. In terms of the synergistic outcome of the design, our mesh can remarkably attenuate inflammation and promote constructive tissue regeneration in vivo. Furthermore, considering the relatively simple and easily scaled up formulation process, our strategy may indeed have great potential in alleviating post-implantation outcomes.

Recyclable, flame-retardant and smoke-suppressing tannic acid-based carbon-fiber-reinforced plastic

Recent environmental issues have driven the development of bioderived chemicals for new composite materials and recycling methods. This paper presents the use of tannic acid (TA)-based epoxy as a polymeric matrix for fabricating and recycling carbon-fiber-reinforced plastic (CFRP). TA plays a critical role in increasing the adhesion of the interface between a polymeric matrix and carbon fiber (CF), ultimately improving the mechanical properties of the CFRP. In addition, its char forming ability endows the CFRP with flame-retarding and smoke-suppressing properties. TA-based CFRP can be treated with supercritical deionized water (scDW) with no additives, producing carbon spheres from the degradation of the epoxy matrix and clean CFs. Each product can be applied as various materials for different purposes. In this paper, a new paradigm is suggested to fully recycle epoxy-based CFRP composites.

Metal Ion-Chelated Tannic Acid Coating for Hemostatic Dressing.

Tannic acid (TA), a high-molecular-weight polyphenol, is used as a hemostasis spray and unguent for trauma wound remedy in traditional medical treatment. However, the use of tannic acid on a large-area wound would lead to absorption poisoning. In this work, a TA coating was assembled on a quartz/silicon slide, or medical gauze, via chelation interaction between TA and Fe3+ ions and for further use as a hemostasis dressing. Protein adsorption on the TA coating was further investigated by fluorescence signal, ellipsometry analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The adsorbed bovine serum albumin (BSA), immunoglobulin G (IgG) and fibrinogen (Fgn) on the TA coating was in the manner of monolayer saturation adsorption, and fibrinogen showed the largest adsorption. Furthermore, we found the slight hemolysis of the TA coating caused by the lysed red blood cells and adsorption of protein, especially the clotting-related fibrinogen, resulted in excellent hemostasis performance of the TA coating in the blood clotting of an animal wound. Thus, this economic, environmentally friendly, flexible TA coating has potential in medical applications as a means of preparing novel hemostasis materials.

Multiple modifications of BiVO4 through the assembly of metal-phenolic networks for enhanced photocatalytic activity

The natural polyphenol tannic acid is firstly utilized to coordinate with Ru(III) ions to form RuIII-tannic acid complexes shell on the surface of BiVO4 at room temperature. Meanwhile, one-step synthesis of BiVO4@RuIII-tannic acid complexes core-shell embedded with Pd nanoparticles in the shell layer is achieved by the use of tannic acid for coordination and reduction. The photosynergistic effect among the components of BiVO4, RuIII-tannic acid complexes, Pd nanoparticle contributes to the enhanced visible light photocatalytic acitivity. This study will hopefully provide ideas and concepts for designing novel materials for specialized purposes.

Effect of Tannic Acid on Photocatalytic Efficiency of NiFe2O4 and ZnO

ZnO, NiFe2O4, NiFe2O4/TA and NiFe2O4/TA/ZnO photocatalyts were successfully synthesized and characterized, and they demonstrated significant photocatalytic efficiency under visible-light. The photodegradation rates of congo red (CR) are 35.7%, 19.4%, 25.5% and 91.1% over the ZnO, NiFe2O4, NiFe2O4/TA and NiFe2O4/TA/ZnO for 180 min, respectively. The results display that the NiFe2O4/TA/ZnO has the most excellent photocatalytic efficiency for CR among to the other photocatalysts. Furthermore, NiFe2O4/TA/ZnO may be separated easily from solution by magnet because of the magnetic property of NiFe2O4. The considerable increment in efficiency of NiFe2O4/TA/ZnO can be attributed to synergistic effects between NiFe2O4, the tannic acid (TA) and ZnO, which extend lifetime and hinder the recombination of photogenerated charge carriers. This work presents new perspectives on the use of tannic acid based magnetic photocatalysts in wastewater treatment.

Proteolytic degradation of gelatin-tannic acid multilayers

HypothesisGelatin is one of the most popular constituents of biodegradable/edible films. Because of its poor mechanical properties, it typically needs to be cross-linked. In this regard, the use of tannic acid has attracted significant interest. Whereas the biodegradability of gelatin is well established, little is known on how different crosslinking methods affect biodegradability. In most cases, the ionic strength at which protein films are grown has a drastic effect on their structure. Thus, it is expected that by controlling the ionic strength during the growth of cross-linked gelatin films it should be possible to tune the access to relevant cleavage sites by proteases and, therefore, their biodegradability. ExperimentsGelatin-tannic acid were grown at different ionic strengths by means of the layer-by-layer self-assembly method. The growth of these multilayers and their response to the presence of different proteases were monitored by means of Electrochemical Impedance Spectroscopy and Quartz Crystal Microbalance with Dissipation. FindingsGelatin-tannic acid multilayers grown at low ionic strength exhibited a swollen structure that allowed easy access to their cleavage sites by proteases. Multilayers formed at physiological ionic strength exhibited a compacter structure, which limited their proteolytic degradation.