Biotinylated Photocleavable Polyethylenimine:  Capture and Triggered Release of Nucleic Acids from Solid Supports

Abstract

A biotinylated photocleavable polyethylenimine (B-PC-PEI) was designed and synthesized for the capture and controlled release of nucleic acids from solid supports. B-PC-PEI was synthesized via a 3-step reaction process and verified by 1 H NMR and mass spectrometry. In aqueous solution, the o-nitrobenzyl group within B-PC-PEI was efficiently cleaved by 5 min of 365 nm light exposure from a distance of 20 cm (9 mW/cm 2 ). When coupled to streptavidin-coated beads, the PEI domain of Cy5-labeled B-PC-PEI was released by 365 nm light exposure. In contrast, a Cy5-labeled biotinylated PEI (B-PEI) was used as a control and negligible fluorescence loss was observed. Cy5-labeled siRNA was electrostatically captured to streptavidin-coated beads preabsorbed with B-PC-PEI or B-PEI, and flow cytometry demonstrated significant loss of fluorescence from the bead surface after 5 min of light exposure only for B-PC-PEI, demonstrating controlled release of siRNA from the bead surface. Finally, the release of the Cy5-labeled siRNA into the supernatant was quantified. The release of Cy5-siRNA into the supernatant was significantly greater after 5 min of light exposure for B-PC-PEI/streptavidin beads compared to 0 min exposure and remained unchanged for B-PEI/streptavidin beads. B-PC-PEI facilitates capture and triggered release of surface-tethered nucleic acids with light exposure and is fully compatible with streptavidin-based applications.

Synthesis and characterization of mannosylated pegylated polyethylenimine as a carrier for siRNA

“…1 H NMR spectra’s confirmed that both constructs had PEI, PEG and mannose present and the peaks strongly corresponded to previously reported values (Handwerger and Diamond, 2007; Sagara and Kim, 2002). The signal for mannose at 7 ppm was weak due to the relatively low proportion of mannose in the overall construct composition.…”

Light‐Mediated Activation of siRNA Release in Diblock Copolymer Assemblies for Controlled Gene Silencing

“…[30] Specifically, this system provides robust polyplex stability against polyanion- or serum-mediated disassembly, along with light-mediated release of a significant fraction of siRNA following light exposure. Light-induced structural changes remove the hydrophobic and cationic moieties responsible for siRNA binding and elicit a charge reversal along the mPEG- b -P(APNBMA) 23.6 polymer backbone, which may account for the enhanced dissociation of the siRNA structures in this work as compared with other approaches.…”

Light‐Switchable Polymer from Cationic to Zwitterionic Form: Synthesis, Characterization, and Interactions with DNA and Bacterial Cells

“…Cationic polymers with the labile chemical features are the potential candidates to controlled release of RNA or DNA at the locus of delivery and/or required time 3. The mechanisms of release, of varying degree of success, include reductively,4–6 hydrolytically7–11 and photolytically degradable chemical bonds12 as a response to changes in pH, ionic strength, temperature and also light. The release of DNA occurs as a result of either the release of positive charges from the vehicle or switching the positively charged moieties to electrically neutral ones.…”