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| 2. |
- Hedberg, Yolanda S., et al.
(author)
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Can Cobalt(II) and Chromium(III) ions released from joint prostheses influence the friction coefficient?
- 2015
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In: ACS Biomaterial Science and Engineering. - : American Chemical Society (ACS). - 2373-9878. ; 1:8, s. 617-620
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Journal article (peer-reviewed)abstract
- Cobalt chromium molybdenum alloys (CoCrMo) are commonly used as articulating components in joint prostheses. In this tribocorrosive environment, wear debris and metal ionic species are released and interact with proteins, possibly resulting in protein aggregation. This study aimed to investigate whether this could have an effect on the friction coefficient in a typical material couple, namely CoCrMo-on-polyethylene. It was confirmed that both Co(II) and Cr(III) ions, and their combination, at concentrations relevant for the metal release situation, resulted in protein aggregation and its concomitant precipitation, which increased the friction coefficient. Future studies should identify the clinical importance of these findings.
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| 3. |
- Kurut, Anil, et al.
(author)
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Dimerization of Terminal Domains in Spiders Silk Proteins Is Controlled by Electrostatic Anisotropy and Modulated by Hydrophobic Patches
- 2015
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In: ACS Biomaterials Science & Engineering. - : American Chemical Society (ACS). - 2373-9878. ; 1:6, s. 363-371
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Journal article (peer-reviewed)abstract
- The well-tuned spinning technology from spiders has attracted many researchers with the promise of producing high-performance, biocompatible, and yet biodegradable fibers. So far, the intricate chemistry and rheology of spinning have eluded us. A breakthrough was achieved recently, when the 3D structures of the N and C terminal domains of spider dragline silk were resolved and their pH-induced dimerization was revealed. To understand the terminal domains' dimerization mechanisms, we developed a protein model based on the experimental structures that reproduces charge and hydrophobic anisotropy of the complex protein surfaces. Monte Carlo simulations were used to study the thermodynamic dimerization of the N-terminal domain as a function of pH and ionic strength. We show that the hydrophobic and electrostatic anisotropies of the N-terminal domain cooperate constructively in the association process. The dipolar attractions at pH 6 lead to weakly bound dimers by forcing an antiparallel monomer orientation, stabilized by hydrophobic locking at close separations. Elevated salt concentrations reduce the thermodynamic dimerization constant due to screened electrostatic dipolar attraction. Moreover, the mutations on ionizable residues reveal a free energy of binding, proportional to the dipole moment of the mutants. It has previously been shown that dimers, formed at pH 6, completely dissociate at pH 7, which is thought to be due to altered protein charges. In contrast, our study indicates that the pH increase has no influence on the charge distribution of the N-terminal domain. Instead, the pH-induced dissociation is due to an adapted, loose conformation at pH 7, which significantly hampers both electrostatic and hydrophobic attractive interactions.
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| 4. |
- Quellmalz, Arne, et al.
(author)
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Citric acid cross-linked nanocellulose-based paper for size-exclusion nanofiltration
- 2015
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In: ACS Biomaterials Science & Engineering. - : American Chemical Society (ACS). - 2373-9878. ; 1:4, s. 271-276
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Journal article (peer-reviewed)abstract
- This article explores the effect of cross-linking of nanocellulose with citric acid for the development of novel paper filters for potential application within nanofiltration, including sterile (virus) filtration. Cladophora cellulose paper sheets were cross-linked by first soaking in 16 wt % citric acid in the presence of 1 wt % sodium hypophosphate overnight and then curing at 160 degrees C for 10 min in a hot-press. The cross-linked paper filter samples were then characterized with FTIR, AFM, N-2 gas adsorption, and tensile strength analysis (dry and wet strength). The particle retention properties were further studied with respect to filtering of 20 nm Au nanoparticles with SEM and comparing the UV absorbance intensity of the starting solution and the filtrate. The wet strength of the paper filter was greatly improved following the cross-linking, although in the dry state, the paper becomes brittle. The improved wet strength of the paper filter enables increasing the pressure gradient applied for filtration without compromising the integrity of the filter. This is the first report in which a fully nature-derived paper filter is capable of removing tracer particles as small as 20 nm. It is concluded that citric acid cross-linking of nanocellulose is beneficial for developing paper based sterile (virus) removal industrial filters.
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| 5. |
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| 6. |
- Zhou, Juan, et al.
(author)
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Trehalose-Conjugated, Photofunctionalized Mesoporous Silica Nanoparticles for Efficient Delivery of Isoniazid into Mycobacteria
- 2015
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In: ACS Biomaterials Science & Engineering. - : American Chemical Society (ACS). - 2373-9878. ; 1:12, s. 1250-1255
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Journal article (peer-reviewed)abstract
- Glyconanoparticle carriers have been synthesized and efficiently delivered into mycobacteria. Mesoporous silica nanoparticles were functionalized with a,a-trehalose through azide-mediated surface photoligation, and loaded with the antitubercular drug isoniazid. The glyconanoparticles showed high isoniazid loading capacity and higher antimicrobial activity than the free drug.
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