title: HPLC separation of different generations of poly(amidoamine) dendrimers modified with various terminal groups.
abstract: Polyamidoamine (PAMAM) dendrimers of different generations with various terminal groups were analyzed, for the first time, using a combination of high-performance liquid chromatography (HPLC), size exclusion chromatography (SEC), and matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) techniques. Separation of amine-terminated dendrimers from generation 1 through generation 9 (G1NH(2)-G9NH(2)) was achieved using reversed-phase HPLC with elution time increasing gradually as the density of terminal amine groups increases as a function of generation. Furthermore, separation of dendrimers with terminal amino, acetamide, hydroxyl, and carboxylate groups was obtained. It has also been shown that HPLC can be used to separate dendrimers based on some structural defects inherent during the syntheses of PAMAM dendrimers. MALDI-TOF mass spectra of G1NH(2) identify the major imperfections present during typical synthesis processes. The absolute molar masses (M(n)) and molar mass distributions of the dendrimers were measured using the SEC system equipped with multiangle laser light scattering and refractive-index detectors. Findings from this study suggest HPLC can be a vital tool for characterization and preparative separation of PAMAM dendrimers.
authors.affiliation: Center for Biologic Nanotechnology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
authors.forename: Mohammad T
authors.initials: MT
authors.lastname: Islam
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Shi
authors.forename: Lajos
authors.initials: L
authors.lastname: Balogh
authors.forename: James R
authors.initials: JR
authors.lastname: Baker
mesh_terms: D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D050091:Dendrimers / Q000032:analysis* / Q000737:chemistry*; D008970:Molecular Weight; D011073:Polyamines / Q000032:analysis / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000577:Amides; D000588:Amines; D050091:Dendrimers; C104700:PAMAM Starburst; D011073:Polyamines