title: Using capillary electrophoresis to characterize polymeric particles.
abstract: Capillary electrophoresis (CE) was used for the characterization of a variety of polymeric micron and sub-micron particles based on size, surface functionality, and binding properties. First, a robust capillary zone electrophoresis (CZE) method was developed for the baseline separation and quantitation of commercially available polystyrene particles with various surface modifications (including amino, carboxylate, and sulfate functional groups) and various sizes (0.2, 0.5, 1.0, and 3.0μm). The separation of DNA-templated polyacrylamide particles from untemplated particles (as used for the Ion Torrent Personal Genome Machine) was demonstrated. Finally, using the 29-base thrombin aptamer and thrombin protein as a model system, a study was undertaken to determine dissociation constants for the aptamer and protein in free solution and when the aptamer was conjugated to a particle, with the goal of better understanding how the use of solid substrates, like particles, affects selection and binding processes. Dissociation constants were determined and were found to be approximately 5-fold higher for the aptamer conjugated to a particle relative to that in free solution.
authors.affiliation: Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA; Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Riley
authors.affiliation: Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA; Alcami, Wilmington, NC 28405, USA.
authors.forename: Sophia
authors.initials: S
authors.lastname: Liu
authors.affiliation: Nanomedica, LLC, Winston-Salem, NC 27101, USA.
authors.forename: Guo
authors.initials: G
authors.lastname: Yu
authors.affiliation: Nanomedica, LLC, Winston-Salem, NC 27101, USA.
authors.forename: Kara
authors.initials: K
authors.lastname: Libby
authors.affiliation: Nanomedica, LLC, Winston-Salem, NC 27101, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Cubicciotti
authors.affiliation: Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA. Electronic address: colyercl@wfu.edu.
authors.forename: Christa L
authors.initials: CL
authors.lastname: Colyer
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000302:isolation & purification; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry* / Q000302:isolation & purification*; D011485:Protein Binding; D012996:Solutions / Q000737:chemistry; D013816:Thermodynamics; D013917:Thrombin / Q000032:analysis / Q000737:chemistry*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D052157:Aptamers, Nucleotide; D004247:DNA; D011137:Polystyrenes; D012996:Solutions; D013917:Thrombin; D000099166:Polyacrylamides; C081676:thrombin aptamer
keywords: Binding constants; Capillary electrophoresis; DNA-conjugated particles; Ion sphere particles; NECEEM; Polystyrene particles