title: Formulation and surface modification of poly(ester-anhydride) micro- and nanospheres.
abstract: This report presents the formulation and surface modification of poly(ester-anhydride) copolymers. Two synthetic schemes were used to generate a variety of copolymers with varying compositions and molecular weights. These polymers were formulated into both micro- and nanospheres using a water-in-oil-in-water double emulsion technique. Microspheres were between 3 and 10 microm in diameter; whereas, nanospheres were between 300 and 500 nm. Finally, both micro- and nanospheres were surface modified using cystamine and quantified, following cystamine reduction, with DTNB (Ellman's reagent). Surface labeling was observed at 0.20-35 micromol/g for microspheres and 0.6-100 micromol/g for nanospheres and followed the expected trend of increased labeling with increased polyanhydride content.
authors.affiliation: Division of Biological Engineering, Department of Chemical Engineering, Massachusetts Institute of Technology, 45 Carleton Street, E25-342, Cambridge, MA 02142, USA.
authors.forename: Blaine A
authors.initials: BA
authors.lastname: Pfeifer
authors.forename: Jason A
authors.initials: JA
authors.lastname: Burdick
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D004343:Drug Implants / Q000737:chemistry*; D008422:Materials Testing; D008863:Microspheres; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D049388:Polyanhydrides / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D004343:Drug Implants; D049388:Polyanhydrides; D011091:Polyesters