| 1. |
- Abbafati, Cristiana, et al.
(författare)
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- 2020
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Patra, Hirak Kumar, 1981-, et al.
(författare)
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Rational Nanotoolbox with Theranostic Potential for Medicated Pro-Regenerative Corneal Implants
- 2019
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 29:38
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Tidskriftsartikel (refereegranskat)abstract
- Cornea diseases are a leading cause of blindness and the disease burden is exacerbated by the increasing shortage around the world for cadaveric donor corneas. Despite the advances in the field of regenerative medicine, successful transplantation of laboratory‐made artificial corneas is not fully realized in clinical practice. The causes of failure of such artificial corneal implants are multifactorial and include latent infections from viruses and other microbes, enzyme overexpression, implant degradation, extrusion or delayed epithelial regeneration. Therefore, there is an urgent unmet need for developing customized corneal implants to suit the host environment and counter the effects of inflammation or infection, which are able to track early signs of implant failure in situ. This work reports a nanotoolbox comprising tools for protection from infection, promotion of regeneration, and noninvasive monitoring of the in situ corneal environment. These nanosystems can be incorporated within pro‐regenerative biosynthetic implants, transforming them into theranostic devices, which are able to respond to biological changes following implantation.
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| 3. |
- Patra, Hirak Kumar, et al.
(författare)
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Inflammation-sensitive in situ smart scaffolding for regenerative medicine
- 2016
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 8:39, s. 17213-17222
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Tidskriftsartikel (refereegranskat)abstract
- To cope with the rapid evolution of the tissue engineering field, it is now essential to incorporate the use of on-site responsive scaffolds. Therefore, it is of utmost importance to find new 'Intelligent' biomaterials that can respond to the physicochemical changes in the microenvironment. In this present report, we have developed biocompatible stimuli responsive polyaniline-multiwalled carbon nanotube/poly(N-isopropylacrylamide), (PANI-MWCNT/PNIPAm) composite nanofiber networks and demonstrated the physiological temperature coordinated cell grafting phenomenon on its surface. The composite nanofibers were prepared by a two-step process initiated with an assisted in situ polymerization followed by electrospinning. To obtain a smooth surface in individual nanofibers with the thinnest diameter, the component ratios and electrospinning conditions were optimized. The temperature-gated rearrangements of the molecular structure are characterized by FTIR spectroscopy with simultaneous macromolecular architecture changes reflected on the surface morphology, average diameter and pore size as determined by scanning electron microscopy. The stimuli responsiveness of the nanofibers has first been optimized with computational modeling of temperature sensitive components (coil-like and globular conformations) to tune the mechanism for temperature dependent interaction during in situ scaffolding with the cell membrane. The nanofiber networks show excellent biocompatibility, tested with fibroblasts and also show excellent sensitivity to inflammation to combat loco-regional acidosis that delay the wound healing process by an in vitro model that has been developed for testing the proposed responsiveness of the composite nanofiber networks. Cellular adhesion and detachment are regulated through physiological temperature and show normal proliferation of the grafted cells on the composite nanofibers. Thus, we report for the first time, the development of physiological temperature gated inflammation-sensitive smart biomaterials for advanced tissue regeneration and regenerative medicine.
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| 4. |
- Ail, Ujwala, et al.
(författare)
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Thermoelectric Properties of Polymeric Mixed Conductors
- 2016
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 26:34, s. 6288-6296
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Tidskriftsartikel (refereegranskat)abstract
- The thermoelectric (TE) phenomena are intensively explored by the scientific community due to the rather inefficient way energy resources are used with a large fraction of energy wasted in the form of heat. Among various materials, mixed ion-electron conductors (MIEC) are recently being explored as potential thermoelectrics, primarily due to their low thermal conductivity. The combination of electronic and ionic charge carriers in those inorganic or organic materials leads to complex evolution of the thermovoltage (Voc) with time, temperature, and/or humidity. One of the most promising organic thermoelectric materials, poly(3,4-ethyelenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS), is an MIEC. A previous study reveals that at high humidity, PEDOT-PSS undergoes an ionic Seebeck effect due to mobile protons. Yet, this phenomenon is not well understood. In this work, the time dependence of the Voc is studied and its behavior from the contribution of both charge carriers (holes and protons) is explained. The presence of a complex reorganization of the charge carriers promoting an internal electrochemical reaction within the polymer film is identified. Interestingly, it is demonstrated that the time dependence behavior of Voc is a way to distinguish between three classes of polymeric materials: electronic conductor, ionic conductor, and mixed ionic–electronic conductor
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| 5. |
- Ajjan, Fátima, et al.
(författare)
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Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
- 2015
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 3:24, s. 12927-12937
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Tidskriftsartikel (refereegranskat)abstract
- We report spectroelectrochemical studies to investigate the charge storage mechanism of composite polypyrrole/lignin electrodes. Renewable bioorganic electrode materials were produced by electropolymerization of pyrrole in the presence of a water-soluble lignin derivative acting as a dopant. The resulting composite exhibited enhanced charge storage abilities due to a lignin-based faradaic process, which was expressed after repeated electrochemical redox of the material. The in situ FTIR spectroelectrochemistry results show the formation of quinone groups, and reversible oxidation-reduction of these groups during charge-discharge experiments in the electrode materials. The most significant IR bands include carbonyl absorption near 1705 cm(-1), which is attributed to the creation of quinone moieties during oxidation, and absorption at 1045 cm(-1) which is due to hydroquinone moieties.
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| 6. |
- Aminian-Dehkordi, Javad, et al.
(författare)
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A Systems-Based Approach for Cyanide Overproduction by Bacillus megaterium for Gold Bioleaching Enhancement
- 2020
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Ingår i: Frontiers in Bioengineering and Biotechnology. - : Frontiers Media SA. - 2296-4185. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- With the constant accumulation of electronic waste, extracting precious metals contained therein is becoming a major challenge for sustainable development. Bacillus megaterium is currently one of the microbes used for the production of cyanide, which is the main leaching agent for gold recovery. The present study aimed to propose a strategy for metabolic engineering of B. megaterium to overproduce cyanide, and thus ameliorate the bioleaching process. For this, we employed constraint-based modeling, running in silico simulations on iJA1121, the genome-scale metabolic model of B. megaterium DSM319. Flux balance analysis (FBA) was initially used to identify amino acids to be added to the culture medium. Considering cyanide as the desired product, we used growth-coupled methods, constrained minimal cut sets (cMCSs) and OptKnock to identify gene inactivation targets. To identify gene overexpression targets, flux scanning based on enforced objective flux (FSEOF) was performed. Further analysis was carried out on the identified targets to determine compounds with beneficial regulatory effects. We have proposed a chemical-defined medium for accelerating cyanide production on the basis of microplate assays to evaluate the components with the greatest improving effects. Accordingly, the cultivation of B. megaterium DSM319 in a chemically-defined medium with 5.56 mM glucose as the carbon source, and supplemented with 413 μM cysteine, led to the production of considerably increased amounts of cyanide. Bioleaching experiments were successfully performed in this medium to recover gold and copper from telecommunication printed circuit boards. The results of inductively coupled plasma (ICP) analysis confirmed that gold recovery peaked out at around 55% after 4 days, whereas copper recovery continued to increase for several more days, peaking out at around 85%. To further validate the bioleaching results, FESEM, XRD, FTIR, and EDAX mapping analyses were performed. We concluded that the proposed strategy represents a viable route for improving the performance of the bioleaching processes.
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| 7. |
- Aminian-Dehkordi, Javad, et al.
(författare)
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Manually curated genome-scale reconstruction of the metabolic network of Bacillus megaterium DSM319
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Bacillus megaterium is a microorganism widely used in industrial biotechnology for production of enzymes and recombinant proteins, as well as in bioleaching processes. Precise understanding of its metabolism is essential for designing engineering strategies to further optimize B. megaterium for biotechnology applications. Here, we present a genome-scale metabolic model for B. megaterium DSM319, iJA1121, which is a result of a metabolic network reconciliation process. The model includes 1709 reactions, 1349 metabolites, and 1121 genes. Based on multiple-genome alignments and available genome-scale metabolic models for other Bacillus species, we constructed a draft network using an automated approach followed by manual curation. The refinements were performed using a gap-filling process. Constraint-based modeling was used to scrutinize network features. Phenotyping assays were performed in order to validate the growth behavior of the model using different substrates. To verify the model accuracy, experimental data reported in the literature (growth behavior patterns, metabolite production capabilities, metabolic flux analysis using C-13 glucose and formaldehyde inhibitory effect) were confronted with model predictions. This indicated a very good agreement between in silico results and experimental data. For example, our in silico study of fatty acid biosynthesis and lipid accumulation in B. megaterium highlighted the importance of adopting appropriate carbon sources for fermentation purposes. We conclude that the genome-scale metabolic model iJA1121 represents a useful tool for systems analysis and furthers our understanding of the metabolism of B. megaterium.
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| 8. |
- Fernandez-Benito, Amparo, et al.
(författare)
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Green and Scalable Biopolymer-Based Aqueous Polyelectrolyte Complexes for Zinc-Ion Charge Storage Devices
- 2023
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Ingår i: ChemElectroChem. - : WILEY-V C H VERLAG GMBH. - 2196-0216. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Green and scalable materials are essential to fulfill the need of electrification for transitioning into a fossil-fuels free society, and sustainability is a requirement for all new technologies. Rechargeable batteries are one of the most important elements for electrification, enabling the transition to mobile electronics, electrical vehicles and grid storage. We here report synthesis and characterization of polyelectrolyte complexes of alginate and chitosan, both biopolymers deriving from the sea, for transport of zinc ions in hydrogel electrolytes. We have used vibrational spectroscopy, thermal measurements and microscopy, as well as transport measurements with ohmic or blocking contacts. The transference number for zinc ions is close to 1, the conductivity is approximate to 10 mS/cm, with stability at Zn interfaces seen through 7000 cycles in symmetric zinc//zinc cell. A zinc ion aqueous electrolyte was prepared from blends of chitosan and alginate, by using a simple and scalable route. These green zinc ion electrolytes exhibit a stability window up to 2 V, a zinc ion transference number close to 1, and electrochemical cyclability over 7000 cycles at interfaces to zinc. This biologically derived polyelectrolyte complex offers many possibilities for optimizing transport and stability at electrode interfaces.image
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| 9. |
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| 10. |
- Golabi, Mohsen, et al.
(författare)
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Doping Polypyrrole Films with 4-N-Pentylphenylboronic Acid to Enhance Affinity towards Bacteria and Dopamine
- 2016
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Here we demonstrate the use of a functional dopant as a fast and simple way to tune the chemical affinity and selectivity of polypyrrole films. More specifically, a boronic-functionalised dopant, 4-N-Pentylphenylboronic Acid (PBA), was used to provide to polypyrrole films with enhanced affinity towards diols. In order to prove the proposed concept, two model systems were explored: (i) the capture and the electrochemical detection of dopamine and (ii) the adhesion of bacteria onto surfaces. The chemisensor, based on overoxidised polypyrrole boronic doped film, was shown to have the ability to capture and retain dopamine, thus improving its detection; furthermore the chemisensor showed better sensitivity in comparison with overoxidised perchlorate doped films. The adhesion of bacteria, Deinococcus proteolyticus, Escherichia coli, Streptococcus pneumoniae and Klebsiella pneumoniae, onto the boric doped polypyrrole film was also tested. The presence of the boronic group in the polypyrrole film was shown to favour the adhesion of sugar-rich bacterial cells when compared with a control film (Dodecyl benzenesulfonate (DBS) doped film) with similar morphological and physical properties. The presented single step synthesis approach is simple and fast, does not require the development and synthesis of functional monomers, and can be easily expanded to the electrochemical, and possibly chemical, fabrication of novel functional surfaces and interfaces with inherent pre-defined sensing and chemical properties.
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