Gold nanoparticles (AuNPs) are particularly versatile and applicable nanomaterials, illustrated by many biomedical uses.1 Upon excitation of their localised surface plasmon resonance (LSPR) band, plasmonic NPs can undergo efficient light-to-heat transduction generating an efficient and sharp local heating effect.2 NIR illumination of AuNPs is currently being explored in photothermal therapy3 optoacoustic imaging4 and very recently in thermal sensing.5 The LSPR bands of both triangular gold ‘nanonachos’ (AuNNs)6 and gold nanorods (AuNRs)7 can be fine-tuned in the NIR range to exhibit strong absorption in the ‘biological window’.8 Conveniently, AuNPs can be stabilized with polymers to improve their colloidal stability and with biomolecules to improve cellular uptake.9,10
We are also interested in AuNPs functionalized with small-interfering RNA (siRNA) for use as gene delivery systems to treat and prevent disease. The delivery of siRNA can be used as a therapeutic agent to bind cellular mRNA in order to inhibit the translation processes of proteins in the cytoplasm and therefore has an important role in the down-regulation of gene expression.11 We are using siRNA-functionalized AuNPs directed specifically towards treating gastrointestinal cancers.[12]
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8. G. Alfranca, A. Artiga, G. Stepien, M. Moros, S. G. Mitchell*, J. M. de la Fuente*, Nanomedicine 2016, 11, 2903-2916.
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11. J. Conde, A. Ambrosone, V. Sanz, Y. Hernandez, V. Marchesano, F. Tian, H. Child, C. C. Berry, M. R. Ibarra, P. V. Baptista and J. M. Fuente. ACS Nano 2012, 8316–8324.
12. Á. Artiga, I. Serrano-Sevilla, L. De Matteis, S. G. Mitchell, J. M. de la Fuente, J. Mater. Chem. B, 2019, 7, 876-896.