Poly(amido amine) dendrimers (03) modified with poly(y-benzyl-L-glutamate) (number average degree of polymerization, n = 12, 17, and 34) (G3-PBLOs) were prepared successfully by graft polymerization ofy-benzyl-L-glutamateN-carboxy anhydride initiated with amino groups of the dendrimer surface. The hydrodynamic diameters of G3-PBLGs were determined to be 6.9 ± 0.7,8.2 ± 1.0 and 11.9 ± 1.7 nm for n = 12, 17 and 34, respectively, by means of dynamic light scattering. These values were consistent with the theoretical diameters of G3-PBLGs, which were calculated by assuming the completely helical conformation of PBLG segment. G3-PBLGs were found to form stable mono-molecular films at the air-water interface. In addition, these monolayers could be successfully transferred onto various solid substrates. CD and FrIR spectroscopies of the deposited G3-PBLGs monolayers showed that PBLG segments had an a-helical conformation over the wide range of surface pressure even on solid substrates as well as in bulk solutions. Monolayer thicknesses of these LB films, estimated by AFM observations, were compatible with the hydrodynamic diameters of G3-PBLGs.
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