Autotransfecting Short Interfering RNA through Facile Covalent Polymer Escorts

Abstract

Short interfering ribonucleic acids (siRNAs) are important agents for RNA interference (RNAi) that have proven useful in gene function studies and therapeutic applications. However, the efficacy of exogenous siRNAs for gene knockdown remains hampered by their susceptibility to cellular nucleases and impermeability to cell membranes. We report here new covalent polymer-escort siRNA constructs that address both of these constraints simultaneously. By simple postsynthetic click conjugation of polymers to the passenger strand of an siRNA duplex followed by annealing with the complementary guide strand, we obtained siRNA in which one strand includes terminal polymer escorts. The polymer escorts both confer protection against nucleases and facilitate cellular internalization of the siRNA. These autotransfecting polymer-escort siRNAs are viable in RNAi and effective in knocking down reporter and endogenous genes.

Controlled Radical Polymerization: State-of-the-Art in 2014

“…In the former case, polymers grown from nanoparticles or flat surfaces, dramatically change particles stability, dispersibility and thermomechanical properties, in addition to tremendously enhancing lubricity, antifouling or antibacterial properties (53)(54)(55)(56)(57)(58)(59)(60)(61). Hybrids with proteins or nucleic acids increase stability of proteins in harsh environments, (including temperature, pH, and salts) assist in delivery of genes, and can be used in advanced drug delivery (45,(62)(63)(64)(65)(66)(67)(68)(69)(70)(71).…”

Conformation–function relationships for the comb-shaped polymer pOEGMA

“…This was notably observed for a bio-conjugate of P2-stat-P9 and trypsin [74]. pOEGMA has also been used for similar purposes to protect DNA (or RNA) within self-assembled supramolecular structures such as complex coacervate core micelles or by covalent conjugation [75][76][77]. For example, Averick et al [77] modified siRNA with two copies of either P9, P2-stat-P5, or P9-stat-N,N-dimethylaminoethyl methacrylate (DMAEMA), one at each extremity.…”

“…pOEGMA has also been used for similar purposes to protect DNA (or RNA) within self-assembled supramolecular structures such as complex coacervate core micelles or by covalent conjugation [75][76][77]. For example, Averick et al [77] modified siRNA with two copies of either P9, P2-stat-P5, or P9-stat-N,N-dimethylaminoethyl methacrylate (DMAEMA), one at each extremity. Interestingly, the authors demonstrated that the polymer-siRNA architecture simultaneously imparted protection from nucleases as well as cell permeability.…”

Reductive nanocomplex encapsulation of cRGD-siRNA conjugates for enhanced targeting to cancer cells

“…However, in current studies of siRNA conjugates, more attention has been paid to the 3′-terminus of sense strand. Meanwhile, there are a few literatures reporting bis-conjugated siRNAs, such as 3′,3″-bis-phospholipidsiRNA conjugate, 12 3′,3″-bis-polymer-siRNA conjugate 13 and 3′,3″-bis-peptide-siRNA conjugate. 14 In our previous research, we used a peptide derivative, CPG, to develop a relatively simple strategy to prepare peptide-siRNA conjugates in which hydrophobic hexapeptide (KALLAL) was conjugated at 3′-terminus of single oligonucleotide.…”