Synthesis And Application Of Photoresponsive PEG-b-Poly((N-o-nitrobrnzyloxycarbonyl-aminoethyl)glycine)copolymer

As a natural macromolecule,protein is an important part of organisms.Polypeptoid with excellent biocompatibility and degradability is similar backbone to protein,and has been extensively studied in biomedicine.Here,we study the synthetic method and antimicrobial property of photoresponsive polypeptoids,and self-assembly and biological application of triblock copolymer modified by fluorescent probe.1.Synthesis of PEG-b-Poly((N-o-nitrobenzyloxycarbonyl-aminoethyl)glycine): We synthesized photoresponsive monomers(oNB-NCA)contained photoresponsive o-nitrobenzyl group.Photoresponsive polypeptide block polymer was synthesized by ring-opening polymerization using PEG-NH2 as macroinitiator and oNB-NCA as monomer.2.Upon the UV irradiation,the antimicrobial activity of PEG-b-Poly((N-o-nitrobenzyloxycarbonyl-aminoethyl)glycine): In PEG-b-PN(oNB)G,the cleavage degree of o-nitrobenzyl groups increases as UV irradiation time increases.Upon the UV irradiation,the polypeptoid possessed antimicrobial activity.We prepared the photoresponsive antimicrobial hydrogel using the agrose as substrate materials doped with PEG-b-PN(oNB)G.The surfaces of antimicrobial hydrogel with UV irradiation could kill all bacteria,and reuse.The amino group generated by the UV irradiation as hydrophilic group and o-nitrobenzyl group as hydrophobic group lead to the antimicrobial activity of polymer and hydrogel.3.Self-assembly and biological application of triblock copolymer modified by fluorescent probe(PEG-b-PGA-b-PNOG-Probe): PEG-b-PGA-b-PNOG was synthesized by ring-opening polymerization(ROP)using PEG-NH2 macroinitiator.The fluorescent probe reacted with activated carboxyl using EDC and NHS in PEG-b-PGA-b-PNOG.In 1 mg/mL concentration,PEG-b-PGA-b-PNOG-Probe could self-assemble into large sheets.We studied the cellular uptakes.The results of AFM show that large sheet was comprised of thin sheets with 5.5 nm thick.