Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles

  • Vanesa Sanz
  • João Conde
  • Yulán Hernández
  • Pedro V. Baptista
  • M. R. Ibarra
  • Jesús M. de la Fuente
Research Paper

Abstract

The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold–thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs (~14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

Keywords

Gold nanoparticles PEG biofunctional spacers TAT peptide dsRNA oligonucleotide Surface science 

Supplementary material

11051_2012_917_MOESM1_ESM.doc (252 kb)
TEM images of AuNP; Determination of the degree of saturation of AuNPs functionalized with thiolated PEG chains; Procedure for the determination of the bound TAT peptide by the EDC coupling reaction to functionalized AuNPs; Quantification of the dsRNA strands loaded into AuNPs. (DOC 252 kb)

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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Vanesa Sanz
    • 1
  • João Conde
    • 1
    • 2
  • Yulán Hernández
    • 1
  • Pedro V. Baptista
    • 2
  • M. R. Ibarra
    • 1
  • Jesús M. de la Fuente
    • 1
  1. 1.Instituto de Nanociencia de AragónUniversidad de ZaragozaZaragozaSpain
  2. 2.Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Centro de Investigação em Genética Molecular HumanaUniversidade Nova de LisboaCaparicaPortugal

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