<scp>RAFT</scp> Synthesis of Photo Cross‐Linkable Tyrosine‐Containing Copolymers With Self‐Assembling and Thermoresponsive Properties

ABSTRACT Tyrosine is a proteinogenic amino acid with phenol functionality. Dityrosine cross‐linking is a key component in the development of novel functional biomaterials with tunable assemblies and mechanical properties. Herein, we report the synthesis of two series of photo cross‐linkable tyrosine‐containing copolymers by reversible addition‐fragmentation chain‐transfer (RAFT) copolymerization of N ‐acryloyl‐ L ‐tyrosine (ATyrOH) with N ‐acryloyl‐ L,L ‐diphenylalanine (APhePheOH) acting as a self‐assembling motif and N ‐isopropylacrylamide (NIPAM), exhibiting thermoresponsive properties. P(APhePheOH‐ co ‐ATyrOH)s with different co‐monomer compositions afforded self‐assembled structures (rigid and flexible fibers with different diameters and lengths). Dityrosine bond formation of P(APhePheOH‐ co ‐ATyrOH) was investigated under LED‐UV irradiation ( λ = 265 nm), which was evaluated by comparison of the blue fluorescence excitation‐emission at 405 nm. Owing to the presence of the carboxylic acid unit and the phenol functionality of ATyrOH, P(NIPAM‐ co ‐ATyrOH)s displayed thermo‐ and pH‐responsive properties, depending on the composition, and blue luminescence induced by the photo cross‐linking reaction.