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001-es BibID:BIBFORM114853
035-os BibID:(WoS)001048171000001 (Scopus)85169002443
Első szerző:Novák Levente (biológus)
Cím:Synthesis and Characterization of Carboxymethylated Polyethylenimines / Levente Novák, Tamás S. Miklósi, Dávid Nyul, Xiangyang Shi, István Bányai
Dátum:2023
ISSN:2637-6105
Megjegyzések:As potential paramagnetic metal ion complexing macromolecular ligands, carboxymethylated polyethylenimines (CM-PEIs) were successfully prepared from polyethylenimine (PEI) with 2-chloroacetic acid (CA) in an alkaline medium. SEC, pH-potentiometry, DLS, and multinuclear and multidimensional NMR techniques were used to determine the degree of functionalization, size, and possible structure of the modified polymers. By varying the amount of CA, functionalization degrees of 7?67% relative to the theoretical maximum were achieved. Diffusometry shows that the PEI and CM-PEIs are highly hydrated. The CM-PEIs are larger molecules than the parent PEI, although their hydrodynamic size decreases with higher degrees of functionalization. CM-PEIs are isostable except for the most highly substituted derivative. CM-PEIs form complexes with Cu(II) and efficiently decrease the rate of the copper-mediated oxidation of ascorbic acid. The good affinity toward cations of CM-PEI functionalized at 67% is further demonstrated by its capacity to bind even sodium ions. These properties show that CM-PEIs are promising metal-chelating polymers for diagnostic or theranostic purposes.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
karboximetilezett polietilénimin
progresszív funkcionalizáció
polimer jellemzés
többdimenziós és multinukleáris NMR
protonaffinitás spektrum
réz(II)-komplex
nátrium kötés
makromolekuláris ligandum
Megjelenés:ACS Applied Polymer Materials. - 5 : 9 (2023), p. 7208-7219. -
További szerzők:Miklósi Tamás Sándor (PhD hallgató) Nyul Dávid (1993-) (vegyészmérnök) Shi, Xiangyang Bányai István (1953-) (vegyész)
Pályázati támogatás:NKFIH KA_131989
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2.

001-es BibID:BIBFORM085630
Első szerző:Shi, Xiangyang
Cím:Generational, skeletal and substitutional diversities in generation one poly(amidoamine) dendrimers / Xiangyang Shi, István Bányai, Mohammad T. Islam, Wojciech Lesniak, Denzel Z. Davis, James R. Baker, Lajos P. Balogh
Dátum:2005
ISSN:0032-3861
Megjegyzések:Structural deviations of ethylenediamine core polyamidoamine (PAMAM) dendrimers and derivatives can be defined as skeletal and/or substitutional diversities. Detailed analysis of dendrimer starting materials and derivatives is necessary to understand the intrinsic characteristics of commercial dendrimer materials and their variations related to subsequent surface modifications. In this paper, structural deviations of ethylenediamine core generation 1 PAMAM dendrimers (PAMAM_E1 or E1) are studied and determined in a frame of a systematic investigation using combined characterization techniques. A primary amine-terminated PAMAM dendrimer of generation 1 (E1.NH2) was used as a starting material to synthesize glycidol (E1.N(Gly)OH) and acetamide-terminated (E1.NHAc) dendrimers. The purity and homogeneity of these dendrimers were extensively characterized by polyacrylamide gel electrophoresis (PAGE), capillary electrophoresis (CE), gel permeation chromatography (GPC), acid?base titration, nuclear magnetic resonance (NMR), matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and electrospray ionization (ESI) mass spectrometry. PAGE and CE studies showed that electrophoretic mobilities at pH 2.5 are in the order of E1.NH2>E1.N(Gly)OH>E1.NHAc. Mass spectrometry and NMR investigations (1H, 13C DEPT-135, and 13C NMR, COSY, HETCOR, NOESY) suggested that (a) the studied E1 dendrimers were generationally pure, (b) E1.NHAc and E1.N(Gly)OH dendrimers, and essentially had the same defects and skeletal diversity as E1.NH2 did. The broad distribution of the main peak in the CE electropherogram of E1.N(Gly)OH revealed the incomplete hydroxylation of E1.NH2 resulting in additional substitutional diversity between the dendrimer molecules. Potentiometric titration studies proved that overall numbers of terminal and tertiary amine groups also deviated from the theoretical values. NMR spectroscopy was applied for both qualitative and quantitative analysis of the structural defects of dendrimers and derivatives. E1.NH2 and E1.NHAc exhibited only minor deviations from ideal structures and, respectively, displayed a narrow distribution; while E1.N(Gly)OH had a much broader distribution centered around 14?3 glycidol substituents. The study of structural variations in generation 1 PAMAMs provides new insights for the characterization of higher generation PAMAM dendrimers and derivatives both in terms of the skeletal deviations as well as other resulting diversities related to dendrimer surface functionalization.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
dendrimer
distribution
Characterization
Megjelenés:Polymer. - 46 : 9 (2005), p. 3022-3034. -
További szerzők:Bányai István (1953-) (vegyész) Islam, Mohammad T. Lesniak, Wojciech G. Davis, Denzel Z. Baker, James R. Balogh Lajos P.
Pályázati támogatás:T-035127
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