title: Silica-polypeptide composite particles: controlling shell growth.
abstract: A method is presented for preparing core-shell silica-polypeptide composite particles with variable and controllable shell growth. The procedure is demonstrated using poly(carbobenzoxy-L-lysine) and poly(benzyl-L-glutamate); after deprotection, these can lead to the most common basic and acidic homopolypeptides, poly(L-lysine) and poly(L-glutamic acid). Control over shell thickness is made possible by sequential addition of N-carboxyanhydride peptide monomer to surfaces that have been functionalized with an amino initiator combined with a surface passivation agent. This results in a series of particles having different shell thicknesses. Variation of shell thickness was evident both in light scattering and in thermogravimetric assays. The shells were visible by transmission electron microscopy; these images along with light scattering measurements suggest the polymers in the shells are highly solvated.
authors.affiliation: Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
authors.forename: Erick
authors.initials: E
authors.lastname: Soto-Cantu
authors.forename: Sibel
authors.initials: S
authors.lastname: Turksen-Selcuk
authors.forename: Jianhong
authors.initials: J
authors.lastname: Qiu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhou
authors.forename: Paul S
authors.initials: PS
authors.lastname: Russo
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Henk
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D010455:Peptides; D012822:Silicon Dioxide