scholarly journals Convergent synthesis of diversified reversible network leads to liquid metal-containing conductive hydrogel adhesives

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yong Xu ◽  
Rebecca Rothe ◽  
Dagmar Voigt ◽  
Sandra Hauser ◽  
Meiying Cui ◽  
...  

AbstractMany features of extracellular matrices, e.g., self-healing, adhesiveness, viscoelasticity, and conductivity, are associated with the intricate networks composed of many different covalent and non-covalent chemical bonds. Whereas a reductionism approach would have the limitation to fully recapitulate various biological properties with simple chemical structures, mimicking such sophisticated networks by incorporating many different functional groups in a macromolecular system is synthetically challenging. Herein, we propose a strategy of convergent synthesis of complex polymer networks to produce biomimetic electroconductive liquid metal hydrogels. Four precursors could be individually synthesized in one to two reaction steps and characterized, then assembled to form hydrogel adhesives. The convergent synthesis allows us to combine materials of different natures to generate matrices with high adhesive strength, enhanced electroconductivity, good cytocompatibility in vitro and high biocompatibility in vivo. The reversible networks exhibit self-healing and shear-thinning properties, thus allowing for 3D printing and minimally invasive injection for in vivo experiments.

2021 ◽  
Author(s):  
Raphaelle Delattre ◽  
Jeremy Seurat ◽  
Feyrouz Haddad ◽  
Thu-Thuy Nguyen ◽  
Baptiste Gaborieau ◽  
...  

The clinical (re)development of phage therapy to treat antibiotic resistant infections requires grasping specific biological properties of bacteriophages (phages) as antibacterial. However, identification of optimal dosing regimens is hampered by the poor understanding of phage-bacteria interactions in vivo. Here we developed a general strategy coupling in vitro and in vivo experiments with a mathematical model to characterize the interplay between phage and bacterial dynamics during pneumonia induced by a pathogenic strain of Escherichia coli. The model estimates some key parameters for phage therapeutic efficacy, in particular the impact of dose and route of administration on phage dynamics and the synergism of phage and the innate immune response on the bacterial clearance rate. Simulations predict a low impact of the intrinsic phage characteristics in agreement with the current semi-empirical choices of phages for compassionate treatments. Model-based approaches will foster the deployment of future phage therapy clinical trials.


Author(s):  
C. B. Ranaweera ◽  
A. K. Chandana

Clitoria ternatea commonly known as Butterfly pea is a standard Ayurvedic medicinal plant used in many parts of south Asian countries. Traditional medicinal plants are a great alternative to find new treatments and for the development of novel antimicrobials to combat many diseases. In Ayurveda and traditional and folk medicine in several countries, decoction and extracts made from C. ternatea are recommended to be used for various medical treatments. C. ternatea extracts claimed to possess antibacterial, antiviral, and antifungal properties, which had been supported and validated by many in vitro and in vivo experiments. However, biologically active compound/s isolation and development novel compounds still remain in its infancy. Despite its enormous potential health benefits, only a single commercial product managed to reach industrial level production. C. ternatea cyclotide studies are also limited despite the fact that it the fastest known natural ligase discovered to date. These cyclotides are rapid peptide ligators and has been the focus of many recent studies on peptide ligation and cyclization for biotechnological applications. In this mini summary we have tried to point out innate unique biological properties of C. ternatea and suggested few future studies, more specifically on C. ternatea cyclotides development against bacterial heat shock proteins (Hsp 100) for novel antimicrobial discovery and development.


2020 ◽  
Author(s):  
sabri ahmed cherrak ◽  
merzouk hafida ◽  
mokhtari soulimane nassima

A novel (COVID-19) responsible of acute respiratory infection closely related to SARS-CoV has recently emerged. So far there is no consensus for drug treatment to stop the spread of the virus. Discovery of a drug that would limit the virus expansion is one of the biggest challenges faced by the humanity in the last decades. In this perspective, testing existing drugs as inhibitors of the main COVID-19 protease is a good approach.Among natural phenolic compounds found in plants, fruit, and vegetables; flavonoids are the most abundant. Flavonoids, especially in their glycosylated forms, display a number of physiological activities, which makes them interesting to investigate as antiviral molecules.The flavonoids chemical structures were downloaded from PubChem and protease structure 6lu7 was from the Protein Data Bank site. Molecular docking study was performed using AutoDock Vina. Among the tested molecules Quercetin-3-O-rhamnoside showed the highest binding affinity (-9,7 kcal/mol). Docking studies showed that glycosylated flavonoids are good inhibitors for the covid-19 protease and could be further investigated by in vitro and in vivo experiments for further validation.


2019 ◽  
Vol 116 (31) ◽  
pp. 15706-15715 ◽  
Author(s):  
Noëlie S. Cayla ◽  
Beza A. Dagne ◽  
Yun Wu ◽  
Yao Lu ◽  
Larry Rodriguez ◽  
...  

Intravenous anesthetic agents are associated with cardiovascular instability and poorly tolerated in patients with cardiovascular disease, trauma, or acute systemic illness. We hypothesized that a new class of intravenous (IV) anesthetic molecules that is highly selective for the slow type of γ-aminobutyric acid type A receptor (GABAAR) could have potent anesthetic efficacy with limited cardiovascular effects. Through in silico screening using our GABAAR model, we identified a class of lead compounds that are N-arylpyrrole derivatives. Electrophysiological analyses using both an in vitro expression system and intact rodent hippocampal brain slice recordings demonstrate a GABAAR-mediated mechanism. In vivo experiments also demonstrate overt anesthetic activity in both tadpoles and rats with a potency slightly greater than that of propofol. Unlike the clinically approved GABAergic anesthetic etomidate, the chemical structure of our N-arylpyrrole derivative is devoid of the chemical moieties producing adrenal suppression. Our class of compounds also shows minimal to no suppression of blood pressure, in marked contrast to the hemodynamic effects of propofol. These compounds are derived from chemical structures not previously associated with anesthesia and demonstrate that selective targeting of GABAAR-slow subtypes may eliminate the hemodynamic side effects associated with conventional IV anesthetics.


Author(s):  
Boris Andryukov ◽  
Natalya Besednova ◽  
Tatyana Kuznetsova ◽  
Tatyana Zaporozhets ◽  
Svetlana Ermakova ◽  
...  

Wound healing involves a complex cascade of cellular, molecular, and biochemical responses and signaling processes. It consists of successive interrelated phases, the duration of which depends on multifactorial processes. Wound treatment is a major healthcare issue that can be resolved by development of effective and affordable wound dressings based on natural materials and biologically active substances. Proper use of modern wound dressings can significantly accelerate wound healing with minimal cosmetic defects. The innovative biotechnologies for creating modern natural interactive dressings are based on sulfated polysaccharides from seaweeds with their unique structures and biological properties, the availability of their sources in the form of wild bushes, and in the form of aquaculture, as well as with a high potential for participation in process control wound healing. These natural biopolymers are a novel and promising biologically active source for designing wound dressings based on alginates, fucoidans, carrageenans, and ulvans, which serve as active and effective therapeutic tools. The aim of this review is to summarize available information about the modern wound dressing’s technologies based on seaweed-derived polysaccharides, including those successfully implemented in commercial products, with the emphasis on promising and innovative designs. The further prospect of using marine biopolymers is related to the need to analyze the results of numerous in vitro and in vivo experiments, summarize clinical trial data, develop a scientifically based approach and relevant practical recommendations for the treatment of wounds.


Author(s):  
Oksana V. Kadyseva ◽  
◽  
Vladimir N. Bykov ◽  
Olga Y. Strelova ◽  
Alexander N. Grebenyuk ◽  
...  

Chitosan are biopolymers that are actively used for the production of local haemostatic agents. The physicochemical characteristics that determine its biological properties include the molecular weight and the deacetylation degree. However, there is no linear relationship between these parameters and haemostatic activity. The most reliable method of confirming the effectiveness is still in vivo experiments. The ability to initiate haemostasis depends on the conformational transition of chitosan macromolecules. The highest efficiency in vitro was for samples in which the transition of a significant part of the molecules from the ‘rigid rod’ state to the ‘globule’ occurred at physiological pH. It is proposed to expand the list of indicators of chitosan that can be controlled to evaluate the quality of raw materials, related to haemostatic activity, to include the definition of the conformational transition at physiological pH.


2020 ◽  
pp. 66-74
Author(s):  
Vanja Tadić ◽  
Nemanja Krgović ◽  
Ana Žugić

Lady's mantle (Alchemilla vulgaris L. syn. Alchemilla xanthochlora Rothm., Rosaceae) has been commonly used in folk medicine to heal inflammations in the mouth, bleeding of the nose, furuncules, gynaecological (menorrhagia and dysmenorrhoea), and gastrointestinal disorders. Although therapeutic indications for lady's mantle are non-specific diarrhoea and gastrointestinal complaints, it has been reported to exert, as well, a variety of biological activities, including wound healing, antimicrobial, neuroprotective, gastroprotective, cytotoxic, and antioxidant. Lady's mantle presents a valuable source of natural bioactive compounds, mostly phenolic compounds - a large amount of tannins, phenolcarboxylic acids, and flavonoids, being responsible for the abovementioned effects. In this work, a literature review of biological properties, investigated in in vitro and in vivo experiments in regard to the determined chemical profile is presented. In addition, the data reported are discussed, and the directions for further investigations are proposed.


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


2019 ◽  
Vol 26 (25) ◽  
pp. 4799-4831 ◽  
Author(s):  
Jiahua Cui ◽  
Xiaoyang Liu ◽  
Larry M.C. Chow

P-glycoprotein, also known as ABCB1 in the ABC transporter family, confers the simultaneous resistance of metastatic cancer cells towards various anticancer drugs with different targets and diverse chemical structures. The exploration of safe and specific inhibitors of this pump has always been the pursuit of scientists for the past four decades. Naturally occurring flavonoids as benzopyrone derivatives were recognized as a class of nontoxic inhibitors of P-gp. The recent advent of synthetic flavonoid dimer FD18, as a potent P-gp modulator in reversing multidrug resistance both in vitro and in vivo, specifically targeted the pseudodimeric structure of the drug transporter and represented a new generation of inhibitors with high transporter binding affinity and low toxicity. This review concerned the recent updates on the structure-activity relationships of flavonoids as P-gp inhibitors, the molecular mechanisms of their action and their ability to overcome P-gp-mediated MDR in preclinical studies. It had crucial implications on the discovery of new drug candidates that modulated the efflux of ABC transporters and also provided some clues for the future development in this promising area.


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