Antibacterial properties and in vivo studies of tannic acid-stabilized silver–halloysite nanomaterials

Clay Minerals ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 112-119
Author(s):  
Anna Stavitskaya ◽  
Christina Shakhbazova ◽  
Yulia Cherednichenko ◽  
Läysän Nigamatzyanova ◽  
Gölnur Fakhrullina ◽  
...  
Keyword(s):  
Tannic Acid ◽  
Antibacterial Properties ◽  
Halloysite Nanotubes ◽  
In Vivo Studies ◽  
Negative Effects ◽  
Antibacterial Performance ◽  
Synthesis Strategy ◽  
Clay Nanotubes

AbstractTannic acid-stabilized silver nanoparticles were synthesized in situ on halloysite clay nanotubes. The synthesis strategy included simple steps of tannic acid adsorption on clay nanotubes and further particle formation from silver salt solution. Pristine halloysite nanotubes as well as amino-modified clays were used for silver stabilization in water or ethanol. The materials were tested for antibacterial performance using three different methods. All of the materials produced showed antimicrobial activity. The pristine halloysite-based material with ~5 nm particles produced using ethanol as the solvent and tannic acid as the reducing agent showed the greatest antibacterial activity against Serratia marcescens. The materials were tested in vivo on Caenorhabditis elegans nematodes to ensure their safety, and they showed no negative effects on nematode growth and life expectancy.

scholarly journals Tannic Acid with Antiviral and Antibacterial Activity as A Promising Component of Biomaterials—A Minireview

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3224 ◽  
Author(s):  
Beata Kaczmarek
Keyword(s):  
Physicochemical Properties ◽  
Tannic Acid ◽  
Phenolic Acid ◽  
Antibacterial Properties ◽  
Biological Properties ◽  
In Vivo Studies ◽  
Biomedical Sciences ◽  
Simplex Virus

As a phenolic acid, tannic acid can be classified into a polyphenolic group. It has been widely studied in the biomedical field of science because it presents unique antiviral as well as antibacterial properties. Tannic acid has been reported to present the activity against Influeneza A virus, Papilloma viruses, noroviruses, Herpes simplex virus type 1 and 2, and human immunodeficiency virus (HIV) as well as activity against both Gram-positive and Gram-negative bacteria as Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Enterococcus faecalis, Pseudomonas aeruginosa, Yersinia enterocolitica, Listeria innocua. Nowadays, compounds of natural origin constitute fundaments of material science, and the trend is called “from nature to nature”. Although biopolymers have found a broad range of applications in biomedical sciences, they do not present anti-microbial activity, and their physicochemical properties are rather poor. Biopolymers, however, may be modified with organic and inorganic additives which enhance their properties. Tannic acid, like phenolic acid, is classified into a polyphenolic group and can be isolated from natural sources, e.g., a pure compound or a component of a plant extract. Numerous studies have been carried out over the application of tannic acid as an additive to biopolymer materials due to its unique properties. On the one hand, it shows antimicrobial and antiviral activity, while on the other hand, it reveals promising biological properties, i.e., enhances the cell proliferation, tissue regeneration and wound healing processes. Tannic acid is added to different biopolymers, collagen and polysaccharides as chitosan, agarose and starch. Its activity has been proven by the determination of physicochemical properties, as well as the performance of in vitro and in vivo studies. This systematics review is a summary of current studies on tannic acid properties. It presents tannic acid as an excellent natural compound which can be used to eliminate pathogenic factors as well as a revision of current studies on tannic acid composed with biopolymers and active properties of the resulting complexes.

scholarly journals Designing P. aeruginosa synthetic phages with reduced genomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diana P. Pires ◽  
Rodrigo Monteiro ◽  
Dalila Mil-Homens ◽  
Arsénio Fialho ◽  
Timothy K. Lu ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Antibacterial Properties ◽  
Genetically Engineered ◽  
In Vivo Studies ◽  
Infection Model ◽  
Promising Therapeutic Approach ◽  
Genes Encoding ◽  
First Time

AbstractIn the era where antibiotic resistance is considered one of the major worldwide concerns, bacteriophages have emerged as a promising therapeutic approach to deal with this problem. Genetically engineered bacteriophages can enable enhanced anti-bacterial functionalities, but require cloning additional genes into the phage genomes, which might be challenging due to the DNA encapsulation capacity of a phage. To tackle this issue, we designed and assembled for the first time synthetic phages with smaller genomes by knocking out up to 48% of the genes encoding hypothetical proteins from the genome of the newly isolated Pseudomonas aeruginosa phage vB_PaeP_PE3. The antibacterial efficacy of the wild-type and the synthetic phages was assessed in vitro as well as in vivo using a Galleria mellonella infection model. Overall, both in vitro and in vivo studies revealed that the knock-outs made in phage genome do not impair the antibacterial properties of the synthetic phages, indicating that this could be a good strategy to clear space from phage genomes in order to enable the introduction of other genes of interest that can potentiate the future treatment of P. aeruginosa infections.

Comparison of the intestinal absorption and bioavailability of γ-tocotrienol and α-tocopherol: in vitro, in situ and in vivo studies

2012 ◽  
Vol 33 (5) ◽  
pp. 246-256 ◽  
Author(s):  
Bilal S. Abuasal ◽  
Hisham Qosa ◽  
Paul W. Sylvester ◽  
Amal Kaddoumi
Keyword(s):  
Intestinal Absorption ◽  
In Vivo Studies

Inotropic effects of ejection are myocardial properties

1994 ◽  
Vol 266 (3) ◽  
pp. H1202-H1213 ◽  
Author(s):  
P. P. De Tombe ◽  
W. C. Little
Keyword(s):  
Systolic Pressure ◽  
Left Ventricular ◽  
Negative Effects ◽  
Inotropic Effects ◽  
Contraction Duration ◽  
Loading System ◽  
Positive Effect ◽  
Isolated Rat

Recent studies in isolated and in vivo canine hearts have suggested that the left ventricular end-systolic pressure (LVPes) of ejecting beats is the net result of a balance between positive and negative effects of ejection. At present, it is unknown whether these ejection effects are merely a ventricular chamber property or represent a fundamental myocardial property. Accordingly, we examined the effects of ejection in eight isolated rat cardiac trabeculae at the sarcomere level. We approximated in situ sarcomere shortening patterns using an iterative computer loading system. Six isovolumic contractions were compared with four ejecting contractions. The superfusing solution contained either 0.7 mM Ca2+ or 0.65 mM Sr2+ plus 0.15 mM Ca2+. With Ca2+, simulated LVPes ("LVP"es) of ejecting contractions was significantly lower than isovolumic "LVP"es (-5.3 +/- 5.6%), whereas with Sr2+, ejecting "LVP"es was significantly higher than isovolumic "LVP"es (+4.5 +/- 7.5%). Contraction duration and time to end systole were markedly prolonged in ejecting vs. isovolumic contractions with either Ca2+ or Sr2+. As a consequence, comparison of simulated LVP between ejecting and isovolumic beats throughout the contraction, i.e., at the same simulated LVV and time, revealed only a positive effect of ejection with either Ca2+ (+18.8 +/- 5.5%) or Sr2+ (+23.4 +/-9.3%). We conclude that both positive and negative effects of ejection are basic myocardial properties.

scholarly journals GPR21 Inhibition Increases Glucose-Uptake in HepG2 Cells

2021 ◽  
Vol 22 (19) ◽  
pp. 10784
Author(s):  
Gemma K. Kinsella ◽  
Stefania Cannito ◽  
Valentina Bordano ◽  
John C. Stephens ◽  
Arianna C. Rosa ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Hepg2 Cells ◽  
Insulin Signalling ◽  
Hepatic Insulin Resistance ◽  
In Vivo Studies ◽  
Negative Effects ◽  
Cellular Models ◽  
Insulin Signalling Pathway ◽  
Novel Strategy

GPR21 is a constitutively active, orphan, G-protein-coupled receptor, with in vivo studies suggesting its involvement in the modulation of insulin sensitivity. However, its precise contribution is not fully understood. As the liver is both a major target of insulin signalling and critically involved in glucose metabolism, the aim of this study was to examine the role of GPR21 in the regulation of glucose uptake and production in human hepatocytes. In particular, HepG2 cells, which express GPR21, were adopted as cellular models. Compared with untreated cells, a significant increase in glucose uptake was measured in cells treated with siRNA to downregulate GPR21 expression or with the GPR21-inverse agonist, GRA2. Consistently, a significantly higher membrane translocation of GLUT-2 was measured under these conditions. These effects were accompanied by an increased ratio of phAKT(Ser473)/tot-AKT and phGSK-3β(Ser9)/tot-GSK-3β, thus indicating a marked activation of the insulin signalling pathway. Moreover, a significant reduction in ERK activation was observed with GPR21 inhibition. Collectively, these results indicate that GPR21 mediates the negative effects on glucose uptake by the liver cells. In addition, they suggest that the pharmacological inhibition of GPR21 could be a novel strategy to improve glucose homeostasis and counteract hepatic insulin resistance.

scholarly journals Fabrication of Injectable, Porous Hyaluronic Acid Hydrogel Based on an In-Situ Bubble-Forming Hydrogel Entrapment Process

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1138
Author(s):  
Lixuan Wang ◽  
Shiyan Dong ◽  
Yutong Liu ◽  
Yifan Ma ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Regenerative Medicine ◽  
In Vivo Studies ◽  
Injectable Hydrogels ◽  
Cell Behaviors ◽  
Porous Architecture ◽  
In Situ Hydrogel

Injectable hydrogels have been widely applied in the field of regenerative medicine. However, current techniques for injectable hydrogels are facing a challenge when trying to generate a biomimetic, porous architecture that is well-acknowledged to facilitate cell behaviors. In this study, an injectable, interconnected, porous hyaluronic acid (HA) hydrogel based on an in-situ bubble self-generation and entrapment process was developed. Through an amide reaction between HA and cystamine dihydrochloride activated by EDC/NHS, CO2 bubbles were generated and were subsequently entrapped inside the substrate due to a rapid gelation-induced retention effect. HA hydrogels with different molecular weights and concentrations were prepared and the effects of the hydrogel precursor solution’s concentration and viscosity on the properties of hydrogels were investigated. The results showed that HA10-10 (10 wt.%, MW 100,000 Da) and HA20-2.5 (2.5 wt.%, MW 200,000 Da) exhibited desirable gelation and obvious porous structure. Moreover, HA10-10 represented a high elastic modulus (32 kPa). According to the further in vitro and in vivo studies, all the hydrogels prepared in this study show favorable biocompatibility for desirable cell behaviors and mild host response. Overall, such an in-situ hydrogel with a self-forming bubble and entrapment strategy is believed to provide a robust and versatile platform to engineer injectable hydrogels for a variety of applications in tissue engineering, regenerative medicine, and personalized therapeutics.

Tannic acid elicits neurogenic plasma exudation from the in situ hamster cheek pouch

1998 ◽  
Vol 274 (1) ◽  
pp. R237-R242
Author(s):  
Xiao-Pei Gao
Keyword(s):  
Tannic Acid ◽  
Biosynthetic Pathway ◽  
Fluorescein Isothiocyanate ◽  
Cheek Pouch ◽  
Site Formation ◽  
Hamster Cheek Pouch ◽  
Plasma Exudation ◽  
Synthase Inhibitor

The purpose of this study was to determine whether tannic acid elicits neurogenic plasma exudation from the oral mucosa in vivo and, if so, whether this response is transduced in part by thel-arginine-nitric oxide (NO) biosynthetic pathway. Using intravital microscopy, we found that suffusion of tannic acid elicits significant concentration-dependent leaky site formation and increase in clearance of fluorescein isothiocyanate-dextran (molecular mass 70 kDa) from the in situ hamster cheek pouch ( P < 0.05). These effects are significantly attenuated by two selective, but structurally distinct, nonpeptide neurokinin-1 (NK1) receptor antagonists, CP-96,345 and RP-67580, but not by CP-96,344, the 2R,3R enantiomer of CP-96,345. N G-nitrol-arginine methyl ester (l-NAME), an NO synthase inhibitor, but notd-NAME, significantly attenuates tannic acid-induced responses.l-Arginine, but notd-arginine, reverses the attenuating effects of l-NAME. We conclude that tannic acid elicitsl-arginine-NO biosynthetic pathway-dependent neurogenic plasma exudation from the in situ hamster cheek pouch.

scholarly journals Effects of Experimental Agents Containing Tannic Acid or Chitosan on the Bacterial Biofilm Formation in Situ

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1315
Author(s):  
Anton Schestakow ◽  
Matthias Hannig
Keyword(s):  
Hydrochloric Acid ◽  
Tannic Acid ◽  
Biofilm Formation ◽  
Antibacterial Properties ◽  
Positive Control ◽  
Bacterial Biofilm ◽  
Dental Biofilm ◽  
Acid Ph ◽  
Bovine Enamel

Chitosan and tannic acid are known for their antibacterial properties. In the present in-situ study, their antibacterial and anti-adherent effects on biofilm formation on enamel were investigated. Six subjects carried upper jaw splints with bovine enamel specimens, allowing in-situ biofilm formation. During the two-day trial, subjects rinsed with experimental solutions that contained either chitosan, tannic acid (pH = 2.5), tannic acid (pH = 7) or hydrochloric acid. Water served as the negative and chlorhexidine as the positive control. Rinsing occurred four or five times following two different rinsing protocols to investigate both the immediate and long-lasting effects. After 48 h of intraoral exposure, the dental plaque was stained with LIVE/DEAD® BacLight, and fluorescence micrographs were evaluated by using the software ImageJ. The results were verified by scanning electron microscopy. Rinsing with chitosan resulted in little immediate antibacterial and anti-adherent effects but failed to show any long-lasting effect, while rinsing with tannic acid resulted in strong immediate and long-lasting effects. Except for a slightly lower antibacterial effect, the neutral solution of tannic acid was as good as the acidic solution. Hydrochloric acid showed neither an antibacterial nor an anti-adherent effect on dental biofilm formation. Experimental solutions containing tannic acid are promising anti-biofilm agents, irrespective of the pH values of the solutions. Chitosan, on the other hand, was not able to prevent biofilm formation.

scholarly journals In Situ Cross-linking Hydrogel as a Vehicle for Retinal Progenitor Cell Transplantation

2019 ◽  
Vol 28 (5) ◽  
pp. 596-606 ◽  
Author(s):  
Jeayoung Park ◽  
Petr Baranov ◽  
Aybike Aydin ◽  
Hany Abdelgawad ◽  
Deepti Singh ◽  
...  
Keyword(s):  
In Vivo Studies ◽  
Subretinal Space ◽  
Cross Linking ◽  
Post Transplantation ◽  
Ki 67 ◽  
Retinal Progenitor ◽  
Stem Cell Delivery

One of the current limitations of retinal transplantation of stem cells as well as other cell types is the dispersion of cells from the injection site (including loss of cells into the vitreous chamber) and low survival after transplantation. Gelatin-hydroxyphenyl propionic acid (Gtn-HPA) conjugate is a biodegradable polymer that can undergo covalent cross-linking in situ, allowing for injection of incorporated cells through a small caliber needle followed by gel formation in vivo. We tested the hypothesis that Gtn-HPA hydrogel supports survival and integration of retinal progenitor cells (RPCs) post-transplantation. In vitro compatibility and in vivo graft survival were assessed by mixing an equal volume of Gtn-HPA conjugate and RPC suspension and triggering enzyme-mediated gelation, using minute amounts of horseradish peroxidase and peroxide. Immunocytochemistry showed >80% survival of cells and minimal apoptosis for cells incorporated into Gtn-HPA, equivalent to controls grown on fibronectin-coated flasks. RPCs undergoing mitosis were seen within the three-dimensional Gtn-HPA hydrogel, but the percentage of Ki-67-positive cells was lower compared with the monolayer controls. For in vivo studies, gel–cell mixture or cell suspension in saline was trans-sclerally injected into the left eye of female Long Evans rats immunosuppressed with cyclosporine A. Grafts survived at the 1 week time point of the study, with Gtn-HPA-delivered grafts showing less inflammatory response demonstrated by anti-leukocyte staining. More eyes in the gel–cell mixture group showed surviving cells in the subretinal space compared with saline-delivered controls, while the number of cells surviving per graft was not significantly different between the two groups. This work demonstrates an injectable in situ cross-linking hydrogel as a potential vehicle for stem cell delivery in the retina.

NEGATIVE EFFECTS OF VITAMIN K PREPARATIONS ON GLUCURONYL TRANSFERASE ACTIVITY

PEDIATRICS ◽  
1967 ◽  
Vol 40 (6) ◽  
pp. 993-999
Author(s):  
Barbara Jones
Keyword(s):  
Vitamin K ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
In Vivo Studies ◽  
Transferase Activity ◽  
Negative Effects ◽  
Glucuronyl Transferase ◽  
Glucuronide Conjugation

In vitro studies using a mouse liver microsome system failed to demonstrate that menadiol sodium diphosphate, menadione sodium bisulfite, or phytonadione enhanced or inhibited the quantity of ortho-aminophenol glucuronide produced. In vivo studies in young rats with these vitamin K analogues also failed to show an effect on glucuronide conjugation. Based on this data, it is concluded that the hyperbilirubinemia seen in prematures after large doses of water-soluble vitamin K analogues is probably not due to an inhibitory effect of glucuronyl transferase. The evidence suggesting that it may be due in part to hemolysis is briefly reviewed.

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