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.

Dual stimuli‐responsive polypeptide prepared by thiol‐ene click reaction of poly(l‐cysteine) and N, N‐dimethylaminoethyl acrylate

“…Ring‐opening polymerization (ROP) aims for the preparation of biodegradable polymers, such as poly( ε ‐caprolactone) (PCL), poly(trimethylene carbonate) (PTMC), poly(lactic acid) (PLA), polypeptides, and etc . Among them, polypeptides synthesized by ROP of amino acid N ‐carboxyanhydride (NCA) monomers are greatly desirable for biomedical applications due to its good biocompatibility, biodegradability, and biological activity, as well as inherent secondary structures . Providing that dual responsive vinyl monomers could have been introduced onto polypeptides, the biodegradable backbone would be endowed with both temperature and pH sensitivity.…”

“…[15][16][17] Among them, polypeptides synthesized by ROP of amino acid Ncarboxyanhydride (NCA) monomers are greatly desirable for biomedical applications due to its good biocompatibility, biodegradability, and biological activity, as well as inherent secondary structures. [18][19][20][21] Providing that dual responsive vinyl monomers could have been introduced onto polypeptides, the biodegradable backbone would be endowed with both temperature and pH sensitivity. Two issues had to be addressed before such a polypeptide could be achieved.…”

Superfast and Water‐Insensitive Polymerization on α‐Amino Acid N‐Carboxyanhydrides to Prepare Polypeptides Using Tetraalkylammonium Carboxylate as the Initiator

“…Above studies indicate that carboxylate-initiated NCA polymerization using the terminal tetraalkylammonium carbamate as the reactive center is suitable to prepare block copolymers that have extensive applications in self-assembly, [14,27] antimicrobial [1i, 28] and drug delivery. [29] In aproof-ofconcept demonstration, we did block copolymerization on BLL NCA/BLGNCA in THF using TBAA as the initiator in an open vessel at ambient condition, and easily obtained the multiblock polypeptide with 15 blocks of alternate BLL and BLG and with an arrow dispersity ( = 1.07-1.21) after adding each block (Figure 4a,b).…”

Multicompartment Hydrogels

“…Micelles derived from random copolymers were utilized for hydrogel formation as well, e.g., copolymers with OEG and dodecyl sidegroups [ 75 ] or polypeptoids. [ 76 ] Furthermore, melt‐processing of micelle crosslinked hydrogels formed by a copolymerization of acrylic acid (AA) and n ‐octadecyl acrylate was investigated by Okay and co‐workers. [ 77 ] Therefore, micellar hydrogels were formed employing SDS as surfactant.…”