Telechelic Triblock Poly(α-Amino Acid)-Poly(Tetrahydrofuran)-Poly(α-Amino Acid) Copolymers: Chain-End Transformation, Polymerization and pH-Responsive Hydrolysis†

Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects. Poly(alpha-amino acid)-b-poly(tetrahydrofuran)-b-poly(alpha-amino acid) (PAA-PTHF-PAA) is one of the copolymers. In this contribution, di-hydroxyl-ended HO-PTHF-OH is transferred into di-oxyamino-ended H2NO-PTHF-ONH2 quantitatively, which is used as a macroinitiator to polymerize sarcosine N-thiocarboxyanhydride (Sar-NTA) and N-phenyoxycarbonyl N-epsilon-carbobenzyloxy-D-lysine (ZDL-NPC). Well-defined triblock PAA-NHO-PTHF-ONH-PAA is produced with high molecular weight (up to 25.3 kg/mol) and narrow dispersity. The amphiphilic PSar-NHO-PTHF-ONH-PSar (STS) self-assembles into micelles with uniform diameters of 30-40 nm according to DLS. Owing to oxygen amide groups inside the backbone of these copolymers, the polyether-poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.

Automated summary

The study demonstrates that the triblock PAA-NHO-PTHF-ONH-PAA has high molecular weight and narrow dispersity, suitable for applications as polyether-poly(amino acid)s block copolymers. Due to the presence of oxygen amide groups in the backbone, these copolymers are cleavable under acidic conditions, showing potential in smart biomedicine and engineering.