title: Nanofabrication of helical peptide-shelled dendrimers.
abstract: This study describes nanofabrication of helical peptide-shelled dendrimers using a Langmuir monolayer technique. Poly(amido amine) dendrimers (G3) modified with poly(gamma-benzyl-L-glutamate) [number averaged degree of polymerization, n = 12, 17, and 34 (G3-PBLGs hereafter)] were newly prepared by graft polymerization of gamma-benzyl-L-glutamate-N-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 considering the alpha-helical PBLG segment length. G3-PBLGs were found to form stable monomolecular films with high collapse pressures above 40 mN m-1 at the air-water interface. In addition, these monolayers could be successfully transferred onto various solid substrates. Circular dichroism and Fourier transfer infrared spectroscopies of the deposited G3-PBLGs monolayers showed that PBLG segments took an alpha-helical conformation over a wide range of surface pressure even on solid substrates as well as in bulk solutions. Monolayer thicknesses of these Langmuir-Blodgett films, estimated by x-ray photoelectron spectroscopy and atomic force microscopy, were compatible with the hydrodynamic diameters of G3-PBLGs.
authors.affiliation: Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Higashi
authors.forename: T
authors.initials: T
authors.lastname: Koga
authors.forename: M
authors.initials: M
authors.lastname: Niwa
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis* / Q000737:chemistry; D032701:Biomimetics / Q000379:methods; D003460:Crystallization / Q000379:methods; D046911:Macromolecular Substances; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D011073:Polyamines / Q000138:chemical synthesis* / Q000737:chemistry; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010455:Peptides; D011073:Polyamines; D011108:Polymers; C003172:poly-gamma-benzyl-L-glutamate; D011099:Polyglutamic Acid