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- Lo Nostro, P., et al.
(författare)
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Nanoassemblies from vitamin C derivatives
- 2007
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Ingår i: 2007 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2007, Technical Proceedings. - 9781420063424 - 9781420061833 ; 2, s. 9-12
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Konferensbidrag (refereegranskat)abstract
- Vitamin C is one of the most effective natural antioxidants. However, due to its poor solubility in non-aqueous environments, its use is restricted to water-based systems. In order to extend its advantages to lipophilic media, vitamin C must be converted into amphiphilic derivatives. Two new vitamin C-based surfactants were synthesized: a bolaform derivative (1,12-diascorbyl dodecanedioate, BOLA12), and a double chain product (2-octyl-dodecanoyl6-0- ascorbic acid, 8ASC10). Once dispersed in water above 0.5% w/w, BOLA12 forms hollow nanotubes that transform into clear micellar solutions on heating. 8ASC10 is poorly soluble in aqueous media, but it dissolves easily in cyclohexane where it forms true organogels. Cryo-TEM, XRD, SAXS, conductivity, viscosity and DSC experiments were performed in order to study the aggregation properties and morphology of these nanoassemblies.
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| 2. |
- Bombelli, F. B., et al.
(författare)
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DNA Closed Nanostructures: A Structural and Monte Carlo Simulation Study
- 2008
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 112:48, s. 15283-15294
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Tidskriftsartikel (refereegranskat)abstract
- DNA nanoconstructs are obtained in solution by using six unique 42-mer DNA oligonucleotides, whose sequences have been designed to form a pseudohexagonal structure. The required flexibility is provided by the insertion of two non-base-paired thymines in the middle of each sequence that work as flexible hinges and constitute the corners of the nanostructure when formed. We show that hexagonally shaped nanostructures of about 7 nm diameter and their corresponding linear open constructs are formed by self-assembly of the specifically designed linear oligonucleotides. The structural and dynamical characterization of the nanostructure is obtained in situ for the first time by using dynamic light scattering (DLS), a noninvasive method that provides a fast dynamic and structural analysis and allows the characterization of the different synthetic DNA nanoconstructs in solution. A validation of the LS results is obtained through Monte Carlo (MC) simulations and atomic force microscopy (AFM). In particular, a mesoscale molecular model for DNA, developed by Knotts et al., is exploited to perform MC simulations and to obtain information about the conformations as well as the conformational flexibilities of these nanostructures, while AFM provides a very detailed particle analysis that yields an estimation of the particle size and size distribution. The structural features obtained by MC and AFM are in good agreement with DLS, showing that DLS is a fast and reliable tool for characterization of DNA nanostructures in solution. © 2008 American Chemical Society.
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