Reducible, dibromomaleimide-linked polymers for gene delivery

Abstract

Polycations have been successfully used as gene transfer vehicles both in vitro and in vivo; however, their cytotoxicity has been associated with increasing molecular weight. Polymers that can be rapidly degraded after internalization are typically better tolerated by mammalian cells compared to their non-degradable counterparts. Here, we report the use of a dibromomaleimide-alkyne (DBM-alkyne) linking agent to reversibly bridge cationic polymer segments for gene delivery and to provide site-specific functionalization by azidealkyne cycloaddition chemistry. A panel of reducible and non-reducible, statistical copolymers of (2-dimethylamino) ethyl methacrylate (DMAEMA) and oligo(ethylene glycol) methyl ether methacrylate (OEGMA) were synthesized and evaluated. When complexed with plasmid DNA, the reducible and non-reducible polymers had comparable DNA condensation properties, sizes, and transfection efficiencies. When comparing cytotoxicity, the DBM-linked, reducible polymers were significantly less toxic than the non-reducible polymers. To demonstrate polymer functionalization by click chemistry, the DBM-linked polymers were tagged with an azidefluorophore and were used to monitor cellular uptake. Overall, this polymer system introduces the use of a reversible linker, DBM-alkyne, to the area of gene delivery and allows for facile, orthogonal, and site-specific functionalization of gene delivery vehicles.

One-pot thiol–amine bioconjugation to maleimides: simultaneous stabilisation and dual functionalisation

“…To overcome these limitations we, and others, have reported extensively on the use of dibromomaleimides (DBMs), [16][17][18][19][20][21][22][23] and related substituted maleimides known collectively as next generation maleimides (NGMs). 20,24 These reagents retain the favourable kinetics of maleimides 25,26 whilst avoiding the formation of stereoisomers, and through the addition of two thiols allow the construction of dual conjugates (Fig.…”

Microbubbles and ultrasound increase intraventricular polyplex gene transfer to the brain

“…Luciferase or GFP reporter polyplexes were prepared in 5% glucose using 2.5 μg of DNA in 10 μL total volume at an N/P = 15 as previously described [36]. Adult (8–9 weeks) female C57BL/6J mice (Jackson Laboratories) were anesthetized by an intraperitoneal injection of Avertin.…”

Initial Characterization of PDMAEMA: Styrene Porous Polymer Monolithic Morphologies

“…This pH-dependent tunability has made PDMAEMA a material of great interest across multiple fields and applications. It has been studied for its utility in gene delivery, as a sensor, and a mediator for drug encapsulation and release [6][7][8][9][10][11][12][13]. This methacrylate polymer is usually polymerized into self-assembled moieties, brushes, dendrimers, and star-like forms [7,14,15].…”