“Reduction” responsive thymine-conjugated biodynamers: synthesis and solution properties

Thioester chemistry was applied to construct the “reduction” responsive thymine-conjugated biodynamer by a transthioesterification reaction. The copolymers of N,N-dimethylacrylamide (DMA) and pyridyldisulfide ethylacrylamide (PDSEA) were obtained by reversible addition–fragmentation chain transfer (RAFT) radical polymerization, and used as a handle for incorporating thiol-reactive groups onto the copolymers. Thymine thioester reacted with the pendent thiol group produced in situ by the cleavage of PDS. The obtained thymine-conjugated biodynamer containing reversible thioester linkages can interact with the adenine-modified molecule mediated by hydrogen bonding, and demonstrate L-glutathione (GSH)-responsive feature by a thiol–thioester exchange reaction. The biodynamer can also interact with melamine and adenosine-5′-triphosphate (ATP), and form spherical aggregates in water. It is expected that this nucleobase-containing biodynamer has potential applications in the thiol-responsive controlled drug delivery and the construction of complex nanostructures and advanced materials as building blocks.