Synthesis and gelation of copolypept(o)ides with random and block structure

Abstract
Copolypept(o)ides of polysarcosine (PSar) and poly(N‐isopropyl‐L‐glutamine) (PIGA) with random and block sequence structures were synthesized by ring‐opening polymerization (ROP) of sarcosine N‐carboxyanhydrides (Sar‐NCA) and γ‐benzyl‐l‐glutamate N‐carboxyanhydrides (BLG‐NCA) and post modification. With different distribution of Sar along the main chain, H‐bonding pattern and secondary structure of polypeptides were turned, as well as aggregation and gelation behavior. Both copolypept(o)ides formed hydrogels above their critical gelation concentrations (CGCs) without thermo‐sensitivity, which was normally reserved for PEG copolypeptides (eg, PEG‐b‐PIGA). In particular, a different mechanism from previously reported micellar percolation or fibrillar entanglement was suggested for gelation of the random copolypept(o)ide. Therefore, hydrogels from copolymers of PSar and PIGA represented a new approach to construct easy‐handling, biocompatible, biodegradable and thermo‐stable gels that could potentially be applied in biomedical fields.

Random and block copolypept(o)ides of polysarcosine‐co‐poly(N‐isopropyl‐l‐glutamine) (PSar‐co‐PIGA) and polysarcosine‐b‐poly(N‐isopropyl‐l‐glutamine) (PSar‐b‐PIGA) were designed and synthesized via ROP of NCAs of sarcoine (Sar) and γ‐benzyl‐l‐glutamate (BLG) followed by post‐polymerization modification. Copolymerization of Sar with peptide easily altered the hydrogen ...

Source: Biopolymers - August 18, 2017 Category: Biochemistry Authors: Yan Xiao, Jianqiang Wang, Jun Zhang, Andreas Heise, Meidong Lang Tags: ORIGINAL ARTICLE Source Type: research