ATRP under Biologically
Relevant Conditions: Grafting
from a Protein
- Publication date
- Publisher
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/CuCl<sub>2</sub>/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/CuBr<sub>2</sub>/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