Magnetic Nanoparticle-Based Imaging of RNA Transcripts in Breast Cancer Cells
Abstract
We have developed a novel approach to detect RNA transcripts via magnetic resonance by taking advantage of the decrease in the spin-spin (i.e. T2) relaxation time that results from the self-assembly of superparamagnetic iron oxide nanoparticles (NPs). Specifically, two unique NP-oligonucleotide (ON) conjugates were designed to recognize adjacent sites on nucleic acid targets (Figure 1). Thus, upon hybridization to complementary targets the NP-ON conjugate pairs were brought into close proximity, which resulted in a detectable reduction in the T2 relaxation time. This mechanism of switching from a high T2- relaxation time to a low T2-relaxation time is generally referred to as magnetic relaxation switching (MRSw). We tested the ability of NP-ON conjugates with sizes ranging from ~20 nm to 1 um to detect nucleic acid targets. It was found that aminated NPs ~100 nm in diameter performed the best, exhibiting as much as a 61% decrease in T2 signal upon the addition of nucleic acid targets, with a lower detection limit of 10 pmoles. It was also found that the 100 nm particles were rapidly internalized into cells, opening up the possibility of detecting endogenous RNA.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2009
- Accession Number
- ADA537361
Entities
People
- Andrew Tsourkas
Organizations
- University of Pennsylvania