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

Interaction pathways and structure-chemical transformations of alginate gels in physiological environments. Biomacromolecules. 2019 Oct 11;: Authors: Urbanová M, Pavelkova M, Czernek J, Kubova K, Vyslouzil J, Pechova A, Molinkova D, Vysloužil J, Vetchy D, Brus J Abstract The remarkably diverse affinity of alginate (ALG) macromolecules for polyvalent metal ions makes crosslinked 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 crosslinked 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 crosslinking metal ions. Depending on the environment, ALG chains adopted different forms, such as acidic (hydro)gels stabilized by strong hydrogen bonds, and/or weakly crosslinked 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 ...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research