Polymeric micelles were prepared by dropping ethanol into solutions containing（poly（γ-benzyl L-）glutamate）-poly（ethylene oxide） block copolymer （PBLG-b-PEO）,chloroform（CHCl3） and trifluoroacetic acid（TFA）.Viscometry,transmission electron microscopy（TEM）,nuclear magnetic resonance（（）1H-NMR） spectroscopy and infra-red difference spectroscopy（IR） were used to investigate the influence of PBLG chain conformation on the self-assembly behavior of PBLG-b-PEO.The experimental results revealed that PBLG-b-PEO could associate into polymeric micelles in ethanol solutions.The introduction of TFA not only changes the conformation of PBLG segments,but also increases the critical micelle concentration,and further affects the morphologies of the formed micelles.
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.
