Interaction pathways and structure-chemical transformations of alginate gels in physiological environments

0510805 - ÚMCH 2020 RIV US eng J - Journal Article
Urbanová, Martina - Pavelková, M. - Czernek, Jiří - Kubová, K. - Vysloužil, J. - Pechová, A. - Molinková, D. - Vysloužil, J. - Vetchý, D. - Brus, Jiří
Interaction pathways and structure-chemical transformations of alginate gels in physiological environments.
Biomacromolecules. Roč. 20, č. 11 (2019), s. 4158-4170. ISSN 1525-7797. E-ISSN 1526-4602
R&D Projects: GA MŠMT(CZ) LO1507; GA MŠMT(CZ) LTAUSA18011
Grant - others:AV ČR(CZ) StrategieAV21/10
Program: StrategieAV
Institutional support: RVO:61389013
Keywords : alginate gels * molecular-level interactions * physiological conditions
OECD category: Polymer science
Impact factor: 6.092, year: 2019
Method of publishing: Limited access
https://pubs.acs.org/doi/10.1021/acs.biomac.9b01052

The remarkably diverse affinity of alginate (ALG) macromolecules for polyvalent metal ions makes cross-linked alginate gels an outstanding biomaterial. Surprisingly, however, very little is known about their interactions and structural transformations in physiological environments. To bridge this gap, we prepared a set of ALG gels cross-linked by various ions and monitored their structural changes at different media simulating gastric and intestinal fluids and cellular environments. For these studies, we used multinuclear solid-state NMR (ss-NMR) spectroscopy, which revealed a range of competitive ion-exchange and interconversion reactions, the rate of which strongly depended on the nature of the cross-linking metal ions. Depending on the environment, ALG chains adopted different forms, such as acidic (hydro)gels stabilized by strong hydrogen bonds, and/or weakly cross-linked Na/H-gels. Simultaneously, the exchanged polyvalent ions extensively interacted with the environment even forming in some cases insoluble phosphate microdomains directly deposited in the ALG bead matrix. The extent of the transformations and incorporation of secondary phases into the alginate beads followed the size and electronegativity of the cross-linking ions. Overall, the applied combination of various macroscopic and biological tests with multinuclear ss-NMR revealed a complex pathway of alginate beads transformations in physiological environments.
Permanent Link: http://hdl.handle.net/11104/0302383