Self-association behavior of an amphiphilic polypeptide graft copolymer,poly(γ-benzyl L-glutamate)-g-poly(ethylene glycol), and the drug carrier capability of the formed micelles were examined by fluorescence spectro...Self-association behavior of an amphiphilic polypeptide graft copolymer,poly(γ-benzyl L-glutamate)-g-poly(ethylene glycol), and the drug carrier capability of the formed micelles were examined by fluorescence spectroscopy,transmission electron microscopy and UV spectroscopy.It was found that the hydrophobic inner core of the micelles formed by poly(γbenzyl L-glutamate)(PBLG) segments can act as an incorporation site for hydrophobic drugs.The drug-loading content of the graft copolymer micelles tends to be larger when the content of the PBLG segments in the copolymer increases.The results obtained from the drug-release studies showed that the drug-release rates were dependent on the chemical nature of the graft copolymer.展开更多
A novel amphiphilic copolymer poly（ethylene glycol）-block-poly（N,N-dimethylamino-2-ethylmethacrylate）-block- poly[6-（4-methoxy-azobenzene-4＇-oxy） hexyl methacrylate] （PEG-b-PDMAEMA-b-PMMAzo） was prepared by A...A novel amphiphilic copolymer poly（ethylene glycol）-block-poly（N,N-dimethylamino-2-ethylmethacrylate）-block- poly[6-（4-methoxy-azobenzene-4＇-oxy） hexyl methacrylate] （PEG-b-PDMAEMA-b-PMMAzo） was prepared by ATRP polymerization. The self-assembly and responsive behaviors were investigated by SEM, TEM, LLS and UV-Vis spectra. The results indicated that the copolymers can self-assemble into spherical structures in aqueous media. The aggregate size can be tuned by pH and temperature. The trans-cis isomerization behavior of the formed aggregates was also examined. Upon irradiation with a linear polarized light, the elongation degree of the aggregates was increased with the irradiation time.展开更多
Phase transitions of polymer liquid crystals may be i nduced not only by changes of temperature or polymer concentration,but also b y external electric,magnetic or other orientational fields.In this paper the pha se b...Phase transitions of polymer liquid crystals may be i nduced not only by changes of temperature or polymer concentration,but also b y external electric,magnetic or other orientational fields.In this paper the pha se behavior of polypeptide liquid crystal solutions,such as PBLG/TCE and PBLG/CH Cl 3/TFA solutions,was studied in the presence of an external electric field.It was found that the liquid crystal phase was stabilized when the external electr ical field was applied and the area of liquid crystal phase was broadened.Qualit atively,the experimental results are in good agreement with the theoretical resu lts calculated by a lattice model previously.The information obtained may be use d to develop new routes for processing rigid flexible block copolymers with be tter mechanical properties and to construct molecular devices for processing and storing information.展开更多
文摘Self-association behavior of an amphiphilic polypeptide graft copolymer,poly(γ-benzyl L-glutamate)-g-poly(ethylene glycol), and the drug carrier capability of the formed micelles were examined by fluorescence spectroscopy,transmission electron microscopy and UV spectroscopy.It was found that the hydrophobic inner core of the micelles formed by poly(γbenzyl L-glutamate)(PBLG) segments can act as an incorporation site for hydrophobic drugs.The drug-loading content of the graft copolymer micelles tends to be larger when the content of the PBLG segments in the copolymer increases.The results obtained from the drug-release studies showed that the drug-release rates were dependent on the chemical nature of the graft copolymer.
基金financially supported by the National Natural Science Foundation of China(Nos.51103044,21174038 and 50925308)Projects of Shanghai Municipality(11QA1401600 and 13ZZ041)Fundamental Research Funds for the Central Universities(20100074120001,NCET-12-0857 and WD1213002)
文摘A novel amphiphilic copolymer poly（ethylene glycol）-block-poly（N,N-dimethylamino-2-ethylmethacrylate）-block- poly[6-（4-methoxy-azobenzene-4＇-oxy） hexyl methacrylate] （PEG-b-PDMAEMA-b-PMMAzo） was prepared by ATRP polymerization. The self-assembly and responsive behaviors were investigated by SEM, TEM, LLS and UV-Vis spectra. The results indicated that the copolymers can self-assemble into spherical structures in aqueous media. The aggregate size can be tuned by pH and temperature. The trans-cis isomerization behavior of the formed aggregates was also examined. Upon irradiation with a linear polarized light, the elongation degree of the aggregates was increased with the irradiation time.
基金supported by the National Natural Science Foundation of China (52073094,52273291,52073092,52025032 and 12032015)Shanghai Scientific and Technological Innovation Projects (20ZR1415600)。
文摘Phase transitions of polymer liquid crystals may be i nduced not only by changes of temperature or polymer concentration,but also b y external electric,magnetic or other orientational fields.In this paper the pha se behavior of polypeptide liquid crystal solutions,such as PBLG/TCE and PBLG/CH Cl 3/TFA solutions,was studied in the presence of an external electric field.It was found that the liquid crystal phase was stabilized when the external electr ical field was applied and the area of liquid crystal phase was broadened.Qualit atively,the experimental results are in good agreement with the theoretical resu lts calculated by a lattice model previously.The information obtained may be use d to develop new routes for processing rigid flexible block copolymers with be tter mechanical properties and to construct molecular devices for processing and storing information.
