Unveiling the Potential: Exploring Gelation Mechanisms in Alginate Beads Crosslinked with Calcium, Copper and Zinc and their Versatile Applications in Agriculture and Biomedicine

Identifier:  TDX:4312

Handle: https://hdl.handle.net/20.500.11797/TDX4312

Authors:  Reig Vañó, Belén

Abstract:
Encapsulation technology offers protection, stability and a controlled release of encapsulated compounds. Alginate is a natural polysaccharide, which has been widely applied as encapsulating material. However, the influence of gelation conditions on resulting beads has been overlooked, which is crucial for tailored and enhanced hydrogel properties. Calcium, copper and zinc were studied as crosslinking agents at different concentrations: 0.5%, 2% i 10% (w/w). NMR, FT-IR, compression tests, TGA, EXAFS and SAXS analysis were performed to characterize alginate and beads properties. The research highlighted the distinct crosslinking mechanisms and interactions, leading to varied bead structures, compositions and mechanical attributes. Zinc-based beads exhibited promising core-shell structures. Mechanical properties were better in Copper- and Zinc-based systems. Bridging coordination type between alginate residues and cations was proposed. The application of encapsulated cations in Agriculture demonstrated differential effects on mustard seed growth. Alginate beads loaded with biologically active compounds were investigated in Biomedicine, showing varying cytotoxicity effects on 3T3, T24 and SV-HUC-1 cells.