Smart Magnetic Fluorescent Nanoparticle Imaging Probes to Monitor MicroRNAs

An imaging system that can be used to evaluate the expression levels of microRNAs during neuronal development can provide noninvasive information for investigating a variety of biological phenomena related to microRNAs (miRNAs, miRs). Herein, the development of a novel imaging platform to monitor intracellular miR124a during neuronal differentiation is reported using rhodamine-coated cobalt ferrite magnetic fluorescent (MF) nanoparticles linked to a quenching molecular system containing an miR124a binding sequence (MF-miR124a beacon). During neuronal differentiation, in vitro fluorescence signals of the MF-miR124a beacon are significantly increased under conditions where miR124a is highly expressed, and dramatically return to the original quenched fluorescence after anti-miR124a treatment. In vivo fluorescence images show enhanced fluorescence signals in mice with P19 cells within a poly-L-lactic acid scaffold after induction of neuronal differentiation. In addition, magnetic resonance (MR) images provide in vivo tracking of cells containing the MF-miR124a beacon. These studies represent the first step toward the use of nanotechnological imaging of mature miRNA, and this technique could be used for cellular tracking with a MR imaging system as well as for simultaneous monitoring of the miRNA expression pattern in vivo.Mao X, 2009, CHEM COMMUN, P3065, DOI 10.1039/b822582fWu PC, 2008, BIOCONJUGATE CHEM, V19, P1972, DOI 10.1021/bc800092wHwang DW, 2008, EUR J NUCL MED MOL I, V35, P1887, DOI 10.1007/s00259-008-0751-zKim HJ, 2008, J NUCL MED, V49, P1686, DOI 10.2967/jnumed.108.052894Li YS, 2008, BIOCHEM BIOPH RES CO, V373, P457, DOI 10.1016/j.bbrc.2008.05.038Ko MH, 2008, FEBS J, V275, P2605, DOI 10.1111/j.1742-4658.2008.06408.xLee JY, 2008, J NUCL MED, V49, P285, DOI 10.2967/jnumed.107.042507KIM HJ, 2008, MOL IMAGING BIOL, V11, P71Cai WB, 2007, SMALL, V3, P1840, DOI 10.1002/smll.200700351Liu YY, 2007, INT J CANCER, V120, P2527, DOI 10.1002/ijc.22709Cao XW, 2007, GENE DEV, V21, P531, DOI 10.1101/gad.1519207Kim JS, 2006, J VET SCI, V7, P321Leary SP, 2006, NEUROSURGERY, V58, P1009, DOI 10.1227/01.NEU.0000217016.79256.16Cai WB, 2006, NANO LETT, V6, P669, DOI 10.1021/nl052405tYoon TJ, 2006, SMALL, V2, P209, DOI 10.1002/smll.200500360Kim JS, 2006, TOXICOL SCI, V89, P338, DOI 10.1093/toxsci/kfj027So MK, 2006, NAT PROTOC, V1, P1160, DOI 10.1038/nprot.2006.162SHARMA P, 2006, ADV COLLOID INTERFAC, V16, P123KRICHEVSKY AM, 2006, STEM CELLS, V24, P85Giraldez AJ, 2005, SCIENCE, V308, P833, DOI 10.1126/science.1109020Peng XH, 2005, CANCER RES, V65, P1909Mhlanga MM, 2005, NUCLEIC ACIDS RES, V33, P1902, DOI 10.1093/nar/gki302Pachernik J, 2005, PHYSIOL RES, V54, P115SMIMOVA L, 2005, EUR J NEUROSCI, V21, P1469Tan WH, 2004, CURR OPIN CHEM BIOL, V8, P547, DOI 10.1016/j.cbpa.2004.06.010Clapp AR, 2004, J AM CHEM SOC, V126, P301, DOI 10.1021/ja037088bNITIN N, 2004, NUCL ACIDS RES, V32Medintz IL, 2003, NAT MATER, V2, P630, DOI 10.1038/nmat961