2017
Structure and Dynamics of Alginate Gels Cross-Linked by Polyvalent Ions Probed via Solid State NMR Spectroscopy
BRUS, Jiří; Martina URBANOVA; Jiří CZERNEK; Miroslava PAVELKOVÁ; Kateřina KUBOVÁ et al.Základní údaje
Originální název
Structure and Dynamics of Alginate Gels Cross-Linked by Polyvalent Ions Probed via Solid State NMR Spectroscopy
Autoři
BRUS, Jiří; Martina URBANOVA; Jiří CZERNEK; Miroslava PAVELKOVÁ ORCID; Kateřina KUBOVÁ ORCID; Jakub VYSLOUŽIL ORCID; Sabina ABBRENT; Rafal KONEFAL; Jiří HORSKY; David VETCHÝ; Jan VYSLOUŽIL a Pavel KULICH
Vydání
Biomacromolecules, Washington, American Chemical Society, 2017, 1525-7797
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
30104 Pharmacology and pharmacy
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 5.738
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/17:00120342
Organizační jednotka
Přírodovědecká fakulta
UT WoS
EID Scopus
Klíčová slova anglicky
NUCLEAR-MAGNETIC-RESONANCE; EGG-BOX MODEL; SEGMENTAL DYNAMICS; DIVALENT-CATIONS; CALCIUM-ALGINATE; SODIUM ALGINATE; ACID; DELIVERY; COMPLEXATION; COMBINATION
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 4. 11. 2021 13:54, Mgr. Marie Novosadová Šípková, DiS.
Anotace
V originále
Alginate gels are an outstanding biomaterial widely applicable in tissue engineering, medicine, and pharmacy agent delivery, respectively. This contribution provides new and comrehensive into the atomic-resolution structure for cell transplantation, wound healing and efficient bioactive agent delivery, respectively. This contribution provides new and comrehensive insight into the atomic-resolution structure and dynamics of polyvalent ion-cross-linked alginate gels in microbead formulations. By applying various advanced solid-state NMR (ssNMR) spectroscopy techniques, we verified the homogeneous distribution of the cross-linking ions in the alginate gels and the high degree of ion exchange. We also established that the two-component character of the alginate gels arises from the concentration fluctuations of residual water molecules that are preferentially localized along polymer chains containing abundant mannuronic acid (M) residues. These hydrated M-rich blocks tend to self-aggregate into subnanometer domains. The resulting coexistence of two types of alginate chains differing in segmental dynamics was revealed by H-1-C-13 dipolar profile analysis, which indicated that the average fluctuation angles of the stiff and mobile alginate segments were about 5-9 degrees or 30 degrees, respectively. Next, the C-13 CP/MAS NMR spectra indicated that the alginate polymer microstructure was strongly dependent on the type of cross-linking ion. The polymer chain regularity was determined to systematically decrease as the cross linking ion radius decreased. Consistent with the H-1-H-1 correlation spectra, regular structures were found for the gels cross linked by relatively large alkaline earth cations (Ba2+, Sr2+, or Ca2+), whereas the alginate chains cross-linked by bivalent transition metal ions (Zn") and trivalent metal cations (Al3+) exhibited significant irregularities. Notably, however, the observed disordering of the alginate chains was exclusively attributed to the M residues, whereas the structurally well-defined gels all contained guluronic acid (G) residues. Therefore, a key role of the units in M-rich blocks as mediators promoting the self assembly of alginate chains was experimentally confirmed. Finally, combining 2D Al-27 3Q/MAS NMR spectroscopy with density functional theory (DFT) calculations provided previously unreported insight into the structure of the Al3+ cross-linking centers. Notably, even with a low residual amount of water, these cross-linking units adopt exclusively 6-fold octahedral coordination and exhibit significant motion, which considerably reduces quadrupolar coupling constants. Thus, the experimental strategy presented in this study provides a new perspective on cross-linked alginate structure and dynamics for which high-quality diffraction data at the atomic resolution level are inherently unavailable.
Návaznosti
| ED3.2.00/08.0144, projekt VaV |
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| LM2010005, projekt VaV |
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