Multi-functional gold nanoparticles for drug delivery.
ABSTRACT Multi-functional gold nanoparticles have been demonstrated to be highly stable and versatile scaffolds for drug delivery due to their unique size, coupled with their chemical and physical properties. The ability to tune the surface of the particle provides access to cell-specific targeting and controlled drug release. This chapter describes current developments in the area of drug delivery using gold nanoparticles as delivery vehicles for multiple therapeutic purposes.
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ABSTRACT: The surface chemistry of gold nanoparti-cles (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 unde-fined ionic species on citrate-reduced gold nanoparti-cle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such deriv-atives 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 spac-ers 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.Journal of Nanoparticle Research 06/2012; 14(6). DOI:10.1007/s11051-012-0917-2 · 2.28 Impact Factor
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ABSTRACT: Nanotechnology has prompted new and improved materials for biomedical applications with particular emphasis in therapy and diagnostics. Special interest has been directed at providing enhanced molecular therapeutics for cancer, where conventional approaches do not effectively differentiate between cancerous and normal cells; that is, they lack specificity. This normally causes systemic toxicity and severe and adverse side effects with concomitant loss of quality of life. Because of their small size, nanoparticles can readily interact with biomolecules both at surface and inside cells, yielding better signals and target specificity for diagnostics and therapeutics. This way, a variety of nanoparticles with the possibility of diversified modification with biomolecules have been investigated for biomedical applications including their use in highly sensitive imaging assays, thermal ablation, and radiotherapy enhancement as well as drug and gene delivery and silencing. Here, we review the available noble metal nanoparticles for cancer therapy, with particular focus on those already being translated into clinical settings.01/2012; 2012:751075. DOI:10.1155/2012/751075
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ABSTRACT: In the war against cancer, radiotherapy is a prominent tool but counterbalanced by the fact that it also induces damages in healthy tissues. Nanotechnologies could open a new possibility to decrease these side effects. In particular, gold nanoparticles (GNPs) could be used as radio-sensitizers. As the role of proteins in the processes leading to cell death cannot be neglected, their radio-sensitization by GNPs is of great interest. This is particularly true in the case of the human centrin 2 protein, which has been proposed to be involved in DNA repair processes. To investigate this effect, we quantified for the first time the degradation of this protein in a gold colloidal solution when submitted to X-rays. We showed that the X-ray-induced degradation of the human centrin 2 protein is enhanced 1.5-fold in the presence of GNPs, even though no covalent bond exists between protein and GNPs. Among the conditions tested, the maximum enhancement was found with the higher GNP:protein ratio of 2×10−4 and with the higher X-ray energy of 49 keV.Radiation Physics and Chemistry 03/2009; DOI:10.1016/j.radphyschem.2008.11.003 · 1.19 Impact Factor