ATRP under Biologically Relevant Conditions: Grafting from a Protein

Abstract

Atom transfer radical polymerization (ATRP) methods were developed in water-based media, to grow polymers from proteins under biologically relevant conditions. These conditions gave good control over the resulting polymers, while still preserving the protein’s native structure. Several reaction parameters, such as ligand structure, halide species, and initiation mode were optimized in water and PBS buffer to yield well-defined polymers grown from bovine serum albumin (BSA), functionalized with cleavable ATRP initiators (I). The CuCl complex with ligand 2,2′-bipyridyne (bpy) provides the best conditions for the polymerization of oligo­(ethylene oxide) methacrylate (OEOMA) in water at 30 °C under normal ATRP conditions (I/CuCl/CuCl2/bpy = 1/1/9/22), while the CuBr/bpy complex gave better performance in PBS. Activators generated by electron transfer (AGET) ATRP gave well-controlled polymerization of OEOMA at 30 °C with the ligand tris­(2-pyridylmethyl)­amine (TPMA), (I/CuBr2/TPMA = 1/10/11). The AGET ATRP reactions required slow feeding of a very small amount of ascorbic acid into the aqueous reaction medium or buffer. The reaction conditions developed were used to create a smart, thermoresponsive, protein–polymer hybrid.

Cationic Nanogel-mediated Runx2 and Osterix siRNA Delivery Decreases Mineralization in MC3T3 Cells

“…Cationic nanogels were prepared by activators generated by electron transfer atom transfer radical polymerization [5,35,36,[45][46][47][48][49]64] in inverse miniemulsion by copolymerizing quaternized dimethyl aminoethylmethacrylate, oligo(ethylene oxide) methacrylate (M n = 300), and a water-soluble disulfide methacrylate crosslinker with a poly(ethylene glycol 2-bromoisobutyrate) initiator and a copper bromide tris(2-[dimethylamino]ethyl)amine catalyst system dissolved in water. The inverse miniemulsion was prepared by ultrasonication of the aqueous phase in a cyclohexane Span80 solution.…”

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

“…Several well-controlled Cu mediated polymerizations have been performed in water and protic media (98,105,(110)(111)(112). These polymerizations have traditionally been a challenge, due to the low binding constant between Cu II species and halide anions.…”

Conformation–function relationships for the comb-shaped polymer pOEGMA

“…1a) [13,22]. Additionally, the polymerization reaction can take place in aqueous media which enables interfacing with biomaterials [12,21,23], and pOEGMA can be directly grown from initiator-functionalized (bio)macromolecules and solid substrates, providing access to bio-hybrid materials relevant for a variety of sectors [17,18,21,23,24].…”