Multimerized siRNA cross-linked by gold nanoparticles.

In this study, siRNAs terminated with thiol groups were multimerized and cross-linked using ∼5 nm gold nanoparticles (AuNPs) via Au-S chemisorption that can be intracellularly reduced. AuNPs immobilized with single-stranded antisense siRNA were assembled with those with single-stranded sense siRNA via complementary hybridization or assembled with those with single-stranded dimeric sense siRNA. The multimerized siRNA cross-linked by AuNPs showed increased charge density and enhanced enzymatic stability, and exhibited good complexation behaviors with a polycationic carrier, linear polyethylenimine (L-PEI). The resultant multi-siRNA/AuNPs/L-PEI polyelectrolyte complexes exhibited far greater gene silencing efficiencies of green fluorescent protein (GFP) and vascular endothelial growth factor (VEGF) compared to naked siRNA complexes. They could also be visualized by micro-CT imaging. The results suggest that AuNP-mediated multimerization of siRNAs could be a rational approach to achieve both gene silencing and imaging at a target tissue simultaneously.

[1]  Heather L. Tierney,et al.  Dynamics of Thioether Molecular Rotors: Effects of Surface Interactions and Chain Flexibility , 2009 .

[2]  C. Mirkin,et al.  A fluorescence-based method for determining the surface coverage and hybridization efficiency of thiol-capped oligonucleotides bound to gold thin films and nanoparticles. , 2000, Analytical chemistry.

[3]  A. Fire,et al.  Specific inhibition of gene expression by small double-stranded RNAs in invertebrate and vertebrate systems , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[4]  Vincent M Rotello,et al.  Gold nanoparticles in delivery applications. , 2008, Advanced drug delivery reviews.

[5]  Francesco Stellacci,et al.  Divalent Metal Nanoparticles , 2007, Science.

[6]  Vincent M Rotello,et al.  Tunable reactivation of nanoparticle-inhibited beta-galactosidase by glutathione at intracellular concentrations. , 2004, Journal of the American Chemical Society.

[7]  John J Rossi,et al.  RNAi and small interfering RNAs in human disease therapeutic applications. , 2010, Trends in biotechnology.

[8]  Chad A Mirkin,et al.  Biomimetic high density lipoprotein nanoparticles for nucleic acid delivery. , 2011, Nano letters.

[9]  M Geso,et al.  Gold nanoparticles: a new X-ray contrast agent. , 2007, The British journal of radiology.

[10]  Sung Wan Kim,et al.  Efficient siRNA Delivery with Non-viral Polymeric Vehicles , 2009, Pharmaceutical Research.

[11]  T. Tuschl,et al.  Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells , 2001, Nature.

[12]  Subashini Asokan,et al.  Effective gene silencing by multilayered siRNA-coated gold nanoparticles. , 2011, Small.

[13]  Faisal A. Aldaye,et al.  Dynamic DNA templates for discrete gold nanoparticle assemblies: control of geometry, modularity, write/erase and structural switching. , 2007, Journal of the American Chemical Society.

[14]  T. Park,et al.  Efficient intracellular siRNA delivery strategy through rapid and simple two steps mixing involving noncovalent post-PEGylation. , 2009, Journal of controlled release : official journal of the Controlled Release Society.

[15]  So Jin Lee,et al.  Stability and cellular uptake of polymerized siRNA (poly-siRNA)/polyethylenimine (PEI) complexes for efficient gene silencing. , 2010, Journal of controlled release : official journal of the Controlled Release Society.

[16]  Judy Lieberman,et al.  Running interference: prospects and obstacles to using small interfering RNAs as small molecule drugs. , 2006, Annual review of biomedical engineering.

[17]  R. Andino,et al.  The silent treatment: RNAi as a defense against virus infection in mammals. , 2006, Trends in biotechnology.

[18]  Chad A Mirkin,et al.  Maximizing DNA loading on a range of gold nanoparticle sizes. , 2006, Analytical chemistry.

[19]  Weiwei Guo,et al.  Glutathione-mediated release of functional plasmid DNA from positively charged quantum dots. , 2008, Biomaterials.

[20]  T. Park,et al.  siRNA delivery systems for cancer treatment. , 2009, Advanced drug delivery reviews.

[21]  P. Schultz,et al.  Organization of 'nanocrystal molecules' using DNA , 1996, Nature.

[22]  Soo Hyun Lee,et al.  PEG conjugated VEGF siRNA for anti-angiogenic gene therapy. , 2006, Journal of controlled release : official journal of the Controlled Release Society.

[23]  T. Park,et al.  Multimeric small interfering ribonucleic acid for highly efficient sequence-specific gene silencing. , 2010, Nature materials.

[24]  J. Yates,et al.  Surface bonding and dynamical behavior of the CH3SH molecule on Au(111). , 2005, The journal of physical chemistry. B.

[25]  A. Kotlyar,et al.  Synthesis and AFM characterization of poly(dG)-poly(dC)-gold nanoparticle conjugates. , 2010, Bioconjugate chemistry.

[26]  Jae-Seung Lee,et al.  Synthesis and thermally reversible assembly of DNA-gold nanoparticle cluster conjugates. , 2009, Nano letters.

[27]  Christine M. Micheel,et al.  Conformation of oligonucleotides attached to gold nanocrystals probed by gel-electrophoresis , 2003 .

[28]  R. Langer,et al.  Gold, Poly(-amino ester) Nanoparticles for Small Interfering RNA Delivery , 2009 .

[29]  Jean-Paul Behr,et al.  Sticky overhangs enhance siRNA-mediated gene silencing , 2007, Proceedings of the National Academy of Sciences.

[30]  Kangseok Lee,et al.  Modulation of biological processes in the nucleus by delivery of DNA oligonucleotides conjugated with gold nanoparticles. , 2011, Biomaterials.

[31]  Chad A. Mirkin,et al.  Gene regulation with polyvalent siRNA-nanoparticle conjugates. , 2009, Journal of the American Chemical Society.

[32]  A Paul Alivisatos,et al.  Use of plasmon coupling to reveal the dynamics of DNA bending and cleavage by single EcoRV restriction enzymes , 2006, Proceedings of the National Academy of Sciences.

[33]  M. Hepel,et al.  Double-shell gold nanoparticle-based DNA-carriers with poly-L-lysine binding surface. , 2011, Biomaterials.

[34]  J. Storhoff,et al.  A DNA-based method for rationally assembling nanoparticles into macroscopic materials , 1996, Nature.

[35]  M. Brust,et al.  Thiol-specific and nonspecific interactions between DNA and gold nanoparticles. , 2006, Langmuir : the ACS journal of surfaces and colloids.