scholarly journals A Comparison of Chemical and Electrochemical Synthesis of PEDOT:Dextran Sulphate for Bio-Application

2015 ◽  
Vol 1717 ◽  
Author(s):  
Leo R. Stevens ◽  
David G. Harman ◽  
Kerry J. Gilmore ◽  
Marc in het Panhuis ◽  
Gordon G. Wallace

ABSTRACTPoly(3,4-ethylenedioxythiophene) (PEDOT) is an organic conducting polymer that has been the focus of significant research over the last decade, in both energy and biological applications. Most commonly, PEDOT is doped by the artificial polymer polystyrene sulfonate due to the excellent electrical characteristics yielded by this pairing. The biopolymer dextran sulphate (DS) has been recently reported as a promising alternative to PEDOT:PSS for biological application, having electrical properties rivaling PEDOT:PSS, complimented by the potential bioactivity of the polysaccharide. In this work we compared chemical and electrochemical polymerisations of PEDOT:DS in terms of their impact on the electrical, morphological and biological properties of the resultant PEDOT:DS films. Post-growth cyclic voltammograms and UV-Vis analyses revealed comparable redox behaviour and absorbance profiles for the two synthesis approaches. Despite good intrinsic conductivity of particles, the addition of chemically produced PEDOT:DS did not markedly enhance the bulk conductivity of aqueous solutions due to the lack of interconnectivity between adjacent PEDOT:DS particles at achievable concentrations. Scanning electron microscopy revealed significantly greater roughness in films cast from chemically produced PEDOT:DS compared to electropolymerised samples, attributable to the formation of solution phase nanoparticles prior to casting. In cell studies with the L929 cell line, electrochemical polymerisation of PEDOT:DS afforded better integrity of resultant films for surface seeding, whilst chemically polymerised PEDOT:DS appeared to localised at the proliferating cells, suggesting possible applications in drug delivery.

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.


2019 ◽  
Vol 294 ◽  
pp. 65-70
Author(s):  
Kanin Nimcharoensuk ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Vanthana Sattabanasuk ◽  
Panya Sunintaboon ◽  
...  

The objective of this study was to compare the cytotoxicity of a domestically-made light-cured orthodontic adhesive to a commercial adhesive, Transbond XT (3M Unitek, USA). An in-house orthodontic adhesive composed of a filler 60-70 weight % and a monomer ratio (BisGMA:TEGDMA) of 6:4 with 0.5% of photoinitiator was mixed. The potential cytotoxic effect of this experimental and a control adhesive was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay according to ISO 10993-5: 2009(E). The L929 cell line was grown in 96-well tissue culture plates (1x105 cells/mm3). Thin cured-resin discs of each material weighing 0.4 gram were prepared and incubated for 1, 3, 5, 7, 14, and 30 days in Dulbecco’s modified Eagle medium (DMEM) at 37°C and 95% humidity with 5% CO2. The percentage of cell viability was reported by descriptive statistics. The result showed that the cell viability of the experimental adhesive was higher than Transbond XT in all measured periods. The cytotoxicity of both the adhesives gradually decreased with the progression of time. In conclusion, the in-house adhesive showed a good biocompatibility since the first day following polymerization. On the other hand, Transbond XT started with a cytotoxic potential, then, turned to be non-cytotoxic after 5 days of curing.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Surender Verma ◽  
Akash Yadav

Abstract Background Acknowledging population control to be an essential step for global health promotes wide research study in the area of male contraception. Although there are a great number of synthetic contraceptives available in the market, they have plenty of adverse effects. Different potential strategies for male contraception were investigated over a long period time consisting of hormonal, chemical, and immunological interventions, although these methods showed good antifertility results with low failure rates relative to condoms. Main text This review is based upon the concept of herbal contraceptives which are an effective method for controlling the fertility of animals and humans. This review has highlighted herbal medicinal plants and plant extracts which have been reported to possess significant antifertility action in males. The review considers those plants which are used traditionally for their spermicidal and antispermatogenic activities and imbalance essential hormones for fertility purposes and plants with reported animal studies as well as some with human studies for antifertility effect along with their doses, chemical constituents, and mechanism of action of the antifertility effect of the plants. This review also explains the phases of sperm formation, hormone production, and the mechanism of male contraceptives. Conclusion As far as the relevance of the current review is discussed, it might be quite useful in generating monographs on plants and recommendations on their use. A lot of the plant species listed here might appear promising as effective alternative oral fertility-regulating agents in males. Therefore, significant research into the chemical and biological properties of such less-explored plants is still needed to determine their contraceptive efficacy and also to possibly define their toxic effects so that these ingredients can be utilized with confidence to regulate male fertility. The new inventions in this field are necessary to concentrate on modern, more potent drugs with less harmful content and that are self-administrable, less costly, and entirely reversible.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Aline Margarete Furuyama Lima ◽  
Marcelo de Freitas Lima ◽  
Odílio Benedito Garrido Assis ◽  
Alice Raabe ◽  
Hemelen Caroline Amoroso ◽  
...  

In this study, the preparation of porous nanocomposite scaffolds (HX-CNT) from a combination of a hydroxamic derivative of alginate (HX) and an amine-functionalized multiwalled carbon nanotube (CNT) at different concentrations is described. The structure of HX was investigated by FTIR, and the degree of substitution around 9% was confirmed by elemental analysis. The interaction between CNT and alginate derivative in the nanocomposite crosslinked with calcium was confirmed by FTIR, Raman spectroscopy, and SEM. The results obtained in this study showed that scaffolds based on HX-CNT composites with a 4 wt% concentration level exhibited improved physical and mechanical properties compared to plain alginate (Young’s modulus increased from 2.2 to 5.1 MPa and elastic strength from 0.13 to 0.25 MPa) and decreased the swelling ratios from ~900 to ~673. The cytotoxicity assays using the L929 cell line proved that the nanocomposite scaffolds were nontoxic, even at the highest CNT concentration.


Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2772 ◽  
Author(s):  
Husam Hamid Ibrahim ◽  
Mandeep S. J. Singh ◽  
Samir Salem Al-Bawri ◽  
Mohammad Tariqul Islam

The investigation into new sources of energy with the highest efficiency which are derived from existing energy sources is a significant research area and is attracting a great deal of interest. Radio frequency (RF) energy harvesting is a promising alternative for obtaining energy for wireless devices directly from RF energy sources in the environment. An overview of the energy harvesting concept will be discussed in detail in this paper. Energy harvesting is a very promising method for the development of self-powered electronics. Many applications, such as the Internet of Things (IoT), smart environments, the military or agricultural monitoring depend on the use of sensor networks which require a large variety of small and scattered devices. The low-power operation of such distributed devices requires wireless energy to be obtained from their surroundings in order to achieve safe, self-sufficient and maintenance-free systems. The energy harvesting circuit is known to be an interface between piezoelectric and electro-strictive loads. A modern view of circuitry for energy harvesting is based on power conditioning principles that also involve AC-to-DC conversion and voltage regulation. Throughout the field of energy conversion, energy harvesting circuits often impose electric boundaries for devices, which are important for maximizing the energy that is harvested. The power conversion efficiency (PCE) is described as the ratio between the rectifier’s output DC power and the antenna-based RF-input power (before its passage through the corresponding network).


2020 ◽  
Vol 38 (No. 6) ◽  
pp. 337-346
Author(s):  
Emmanuelle Silva ◽  
Juliana Oliveira ◽  
Yhelda Silva ◽  
Stela Urbano ◽  
Danielle Sales ◽  
...  

The objective of this review was to search the literature for studies on the lactoperoxidase system (LPS) as milk natural preservation, action mechanisms, usage methods and perspectives for the dairy industry. A comprehensive literature review approach was conducted for collecting evidence in scientific publications. The biological properties of milk promote the development of microorganisms which compromise its quality, therefore demanding the use of techniques for preserving the milk matrix from its collection until processing. Within this context, LPS could represent an alternative to guarantee the safety of this food in are as where refrigeration is not possible; in addition, studies on applying this system in the dairy industry have been explored, as is the case in the test for verifying pasteurisation efficiency according to determining the lactoperoxidase enzyme activity. Natural antimicrobial properties of LPS make it a promising alternative for the industrial preservation and processing of milk, especially when considering the current quality standard demanded by the market. However, the potential of LPS as a biopreservative is still little technically and scientifically explored, which implies the need to develop new studies.


Author(s):  
Joicy Abraham ◽  
Mahija S. P ◽  
Jency George ◽  
Manjusha W. A

Marine sponges are rich sources of pharmacological active compound. Marine sponge, Dendrilla membranosa was collected from the Vizhingam coast. The sponge extract was tested against eight human bacterial pathogens. The bioactive compounds present in marine sponge were determined by GC-MS analysis. The cytotoxic effect of the sponge was evaluated by using MTT assay. The extracts showed potent anti-bacterial activity against Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogens. The bioactive compound present in marine sponge was identified by GC-MS analysis and the compounds are ethane, butane, formate pentane, Alpha d-galactopyranoside, 2-Ethylhexyl2-ethylhexanoate, Hexahydro hexitol, Styrene, Alpha-d glucopyranoside 1-pentyl-2-proppyl-1-octene, nonadecane, 1,2-benzenedicarboxylic acid, bis-2, Octanoic acid. The test material showed none cytotoxic response to fibroblasts cells. The results of present investigation revealed that, Dendrilla membranosa is a potential source of novel anticancer and antibacterial leads.


Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1416
Author(s):  
Leontina Grigore-Gurgu ◽  
Oana Crăciunescu ◽  
Iuliana Aprodu ◽  
Carmen Alina Bolea ◽  
Andreea Iosăgeanu ◽  
...  

This study focuses on combining different bioprocessing tools in order to develop an in-depth engineering approach for enhancing the biological properties of two valuable food by-products, namely fish waste and yellow onion skins, in a single new bioactive formulation. Bone tissue from phytophagous carp (Hypophthalmichthys molitrix) was used to obtain bioactive peptides through papain-assisted hydrolysis. The peptides with molecular weight lower than 3 kDa were characterized through MALDI-ToF/ToF mass spectrometry and bioinformatics tools. As a prerequisite for microencapsulation, the ability of these peptides to bind the flavonoids extracted from yellow onion skins was further tested through fluorescence quenching measurements. The results obtained demonstrate a considerable binding potency with a binding value of 106 and also the presence of one single or one class of binding site during the interaction process of flavonoids with peptides, in which the main forces involved are hydrogen bonds and van der Waals interactions. In the freeze-drying microencapsulation process, an efficiency for total flavonoids of 88.68 ± 2.37% was obtained, considering the total flavonoids and total polyphenols from the powder of 75.72 ± 2.58 quercetin equivalents/g dry weight (DW) and 97.32 ± 2.80 gallic acid equivalents/g DW, respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on the L929 cell line cultivated in the presence of different concentrations of microencapsulated samples (0.05–1.5 mg/mL) proved no sign of cytotoxicity, the cell viability being over 80% for all the samples.


2019 ◽  
Vol 290 ◽  
pp. 274-279
Author(s):  
Sufiniza Nordin ◽  
Shahrom Mahmud ◽  
Azman Seeni ◽  
Nur Mariam Kamaruddin ◽  
Nur Syuhada Ahmad

In this study, we investigated in vitro toxicity of ZnO nanopowder on L929 fibroblast cell lines. The ZnO nanoparticles were observed to possess relatively more surficial zinc compared to oxygen. Field-emission scanning electron microscope (FESEM) data revealed that the particle morphologies consisted of nanorods, platelets and nodules between 40-100 nm size range. EDS confirmed that there were more zinc elements on the surfaces of the particles. XRD results showed that the calculated average crystallite size of ZnO nanopowder was 44.28 nm. The optical band gap calculated was 3.298 eV based on UV-visible absorption spectra. In vitro toxicity results showed that ZnO concentration at 0.3125mM, 0.625mM and 1.25 mM were considered non-toxic to L929 cell line since the cell viability was higher than 70 % after 72 hours treatment whereas the ZnO nanopowder concentration above 2.5mM was considered toxic. High surficial zinc atoms on ZnO particles could have been a significant factor in cell toxicity.


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