Gold, Poly(β-amino ester) Nanoparticles for Small Interfering RNA Delivery

Abstract

The safe and effective delivery of RNA therapeutics remains the major barrier to their broad clinical application. Here we develop a new nanoparticulate delivery system based on inorganic particles and biodegradable polycations. First, gold nanoparticles were modified with the hydrophilic polymer poly(ethylene glycol) (PEG), and then small interfering RNA (siRNA) was conjugated to the nanoparticles via biodegradable disulfide linkages, with ~30 strands of siRNA per nanoparticle. The particles were then coated with a library of end-modified poly(β-amino ester)s (PBAEs), previously identified as capable of facilitating intracellular DNA delivery. Nanoparticulate formulations developed here facilitate high levels of in vitro siRNA delivery, facilitating delivery as good or better than the commercially available lipid reagent, Lipofectamine 2000.RNA interference (RNAi) is an endogenous process whereby double-stranded RNA (dsRNA) can mediate the catalytic destruction of its homologous mRNA target. Short 22 nt dsRNA fragments called small interfering RNA (siRNA), are intermediates in the process and have shown their potential as therapeutics. 1-4 The development of RNAi based upon synthetic siRNA has led to a variety of potential therapeutic applications for diseases whose conventional treatments are limited. 5-9 The safe and effective intracellular delivery of siRNA remains the most challenging barrier to the broad application of siRNA in the clinic. [10][11][12][13][14] To date a number of carriers have been investigated for their potential as siRNA delivery agents 15 including cationic polymers, 16,17 lipids 8 or lipid-like materials, 18 iron oxide nanoparticles, 19 gold particles, 20-22 and semiconductor nanocrystals. 23,24 Alternatively, siRNA has been chemically modified and conjugated to small organic molecules 25,26 or polymeric materials 12,27,28 to enhance its stability and cellular uptake. 15 Poly(β-amino ester)s (PBAEs) have shown potential as delivery agents for DNA in various cell lines and therapeutic models. [29][30][31][32][33][34][35][36] To the best of our knowledge, however, these materials have not yet demonstrated their ability to deliver siRNA. The disorderly interactions of siRNA with polymer are likely to result in incomplete condensation of the polymer into a particulate due to the stiffer nature of an RNA molecule relative to DNA ( Figure 1A). 37 We hypothesized

Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

“…The technique employs a NIR light trigger to facilitate site specific silencing through biomolecule delivery and the conversion of electronic energy to heat [245][246][247]. Nanocarriers typically target proteins, peptides, nucleic acids, DNA, and RNA [71,241,[248][249][250][251][252][253]. Polymeric structures and liposomes are usually employed as carriers, however, as stated above; polymers are large and cytotoxic and liposomes prone to leakage [254][255][256].…”

15 years on siRNA delivery: Beyond the State-of-the-Art on inorganic nanoparticles for RNAi therapeutics

“…This compound effectively reacts with amine groups on one end (N-hydroxisuccinimide group forming an amide bond) and thiols on the other (pyridil disulfide group that forms a new disulfide bond). Its use has been described with almost all types of inorganic nanoparticles such as AuNPs [25], MNPs [131], QDs [21,119] and carbon nanotubes [17,132]. It has also been reported in the use of products with the same reactive groups as SPDP (i.e.…”

“…Many examples of silencing have used luciferase activity as an indicator of success [25,29,38,45,46].…”

“…The same is true for studies that use GFP as a reporter gene. As GFP is not a native protein, it has limited used for further studies, which would ideally aim at altering native protein levels by using silencing machinery, such as siRNA, miRNA or small molecules [24,25,38]. When verifying protein knockdown, alternative techniques would need to be used such as western blots [143], flow cytometry [45] and In-Cell westerns [144].…”

Multifunctional Gold Nanocarriers for Cancer Theranostics: From Bench to Bedside and Back Again?

“…Several other studies using engineered NPs modified with siRNA have demonstrated a cytoplasmic delivery system of siRNA and efficient gene silencing using AuNPs (Giljohann et al, 2009;Lee et al, 2009;Guo et al, 2010;Lee et al, 2008). However, almost all nanoconjugates using siRNA have exclusively been tested in cell cultures targeting only reporter genes.…”