Cancer Cell Targeting Using Multiple Aptamers Conjugated on Nanorods
- 1 January 2008
- journal article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 80 (3), 567-572
- https://doi.org/10.1021/ac702322j
Abstract
Molecular recognition toward specific cells is a key issue for effective disease, such as cancer, diagnosis and therapy. Although many molecular probes such as aptamers and antibodies can recognize the unique molecular signatures of cancer cells, some of these probes only have relatively weak binding affinities. This results in poor signaling and hinders cell targeting. Here, we use Au−Ag nanorods (NRs) as a nanoplatform for multivalent binding by multiple aptamers on the rod to increase both the signal and binding strengths of these aptamers in cancer cell recognition. Up to 80 fluorophore-labeled aptamers can be attached on a 12 nm × 56 nm NR, resulting in a much stronger fluorescence signal than that of an individual dye-labeled aptamer probe. The molecular assembly of aptamers on the NR surfaces also significantly improves the binding affinity with cancer cells through simultaneous multivalent interactions with the cell membrane receptors. This leads to an affinity at least 26-fold higher than the intrinsic affinity of the original aptamer probes. As determined by flow cytometric measurements, an enhancement in fluorescence signal in excess of 300-fold is obtained for the NR−aptamer-labeled cells compared with those labeled by individual aptamer probes. Therefore, the molecular assembly of aptamers clearly shows potential applications for the elucidation of cells with low density of binding sites, or with relatively weak binding probes, and can thus greatly improve our ability to perform cellular imaging and targeting. This is an excellent example of using nanomaterials to develop advanced molecular binders with greatly improved properties for cellular studies.Keywords
This publication has 16 references indexed in Scilit:
- Maximizing DNA Loading on a Range of Gold Nanoparticle SizesAnalytical Chemistry, 2006
- Aptamers evolved from live cells as effective molecular probes for cancer studyProceedings of the National Academy of Sciences of the United States of America, 2006
- Gold Nanoparticles Quench Fluorescence by Phase Induced Radiative Rate SuppressionNano Letters, 2005
- Cancer Statistics, 2005CA: A Cancer Journal for Clinicians, 2005
- Preparation and Growth Mechanism of Gold Nanorods (NRs) Using Seed-Mediated Growth MethodChemistry of Materials, 2003
- Fluorescence Quenching of Dye Molecules near Gold Nanoparticles: Radiative and Nonradiative EffectsPhysical Review Letters, 2002
- Systematic Evolution of a DNA Aptamer Binding to Rat Brain Tumor MicrovesselsPublished by Elsevier BV ,2001
- Adsorption of proteins onto surfaces containing end-attached oligo(ethylene oxide): a model system using self-assembled monolayersJournal of the American Chemical Society, 1993
- In vitro selection of RNA molecules that bind specific ligandsNature, 1990
- Systematic Evolution of Ligands by Exponential Enrichment: RNA Ligands to Bacteriophage T4 DNA PolymeraseScience, 1990