Aptamer-conjugated, fluorescent gold nanorods as potential cancer theradiagnostic agents

Abstract

GNRs are emerging as a new class of probes for theradiagnostic applications thanks to their unique optical properties. However, the achievement of proper nanoconstructs requires the synthesis of highly pure GNRs with well-defined aspect ratio (AR), in addition to extensive surface chemistry modification to provide them with active targeting and, possibly, multifunctionality. In this work, we refined the method of the seed mediated growth and developed a robust procedure for the fabrication of GNRs with specific AR. We also revealed and characterized unexplored aging phenomena that follow the synthesis and consistently alter GNRs' final AR. Such advances appreciably improved the feasibility of GNRs fabrication and offered useful insights on the growth mechanism. We next produced fluorescent, biocompatible, aptamer-conjugated GNRs by performing ligand exchange followed by bioconjugation to anti-cancer oligonucleotide AS1411. In vitro studies showed that our nanoconstructs selectively target cancer cells while showing negligible cytotoxicity. As a result, our aptamer-conjugated GNRs constitute ideal cancer-selective multifunctional probes and promising candidates as photothermal therapy agents.

Combined Magnetic Resonance Imaging and Photodynamic Therapy Using Polyfunctionalised Nanoparticles Bearing Robust Gadolinium Surface Units

“…In order to explore this targeting concept, a thiol‐functionalised folic acid group (FA‐SH, 11 ) we have previously used was added to the assembly to investigate uptake in HeLa cells, which express folate receptors on their surface to a greater degree than MCF‐7 cells . More complex alternatives, such as DNA/RNA aptamers, can also be used . The modular conjugation of different thiol‐based targeting moieties (some of which are commercially available), tailored to recognise specific proteins or receptors, indicates the versatility of the proposed nanoparticles and their potential use as combined imaging and therapy platforms.…”

“…In conjunction with this effect, the selectivity of the material for certain cell types can be dramatically increased by the addition of targeting surface units, such as aptamers or antibodies . Gold nanostructures bearing aptamers show very specific protein binding, bringing the material into the proximity of the target protein, allowing targeting to be combined with therapy (such as PTT) to achieve localised destruction of cells …”

“…[11] Gold nanostructures bearing aptamerss howv ery specific protein binding, bringing the material into the proximity of the target protein, allowing targeting to be combined with therapy (such as PTT) to achieve localised destruction of cells. [12][13][14] Magnetic resonance imaging (MRI) is an on-invasivet echnique that exploits the same principles as NMR to acquire detailed anatomical images with the highest spatial resolution of all the imaging modalities. In the body,d ifferent tissue types possess diversef undamentalr elaxation parameters (T 1 /T 2 )a sa resulto ft heir different proton densities.…”

Modulatory Functionalization of Gold Nanorods Using Supramolecular Assemblies

“…In addition, GNRs with different charges can broaden the scope in various biomedical applications owing to charge‐dependent cellular uptake and programmable interactions with biomolecules such as proteins and nucleic acids . In particular, COOH‐functionalized GNRs can be used as a precursor for further conjugation of GNRs with various biomaterials involving drugs, probes, and targeting moieties . In this study, supramolecular‐assembly‐mediated functionalization of GNRs has been developed by reversible phase transfer between water and oils, which offers a facile method for fabricating robust GNRs with surface‐charge tunability.…”

“…[16] In particular,C OOH-functionalized GNRs can be used as ap recursor for further conjugationo fG NRs with various biomaterials involvingd rugs,p robes, and targeting moieties. [17] In this study, supramolecular-assembly-mediatedf unctionalization of GNRs has been developedb yr eversiblep hase transfer between water and oils, which offers af acile methodf or fabricating robust GNRs with surface-charge tunability.…”