Accession Number : ADA537361


Title :   Magnetic Nanoparticle-Based Imaging of RNA Transcripts in Breast Cancer Cells


Descriptive Note : Annual rept. 1 Jun 2008-31 May 2009


Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA


Personal Author(s) : Tsourkas, Andrew


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a537361.pdf


Report Date : 01 Jun 2009


Pagination or Media Count : 40


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.


Descriptors :   *BREAST CANCER , *RIBONUCLEIC ACIDS , *CELLS(BIOLOGY) , NUCLEIC ACIDS , RELAXATION TIME , MAGNETIC RESONANCE , DETECTION , RECORDS


Subject Categories : Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE