PRONOVA® sodium alginates

PRONOVA® sodium alginates product group belongs to a family of highly purified and well-characterized alginates developed for use in biomedical and pharmaceutical applications.
Alginate is one of the most versatile biopolymers. It is in commercial use or in advanced clinical evaluation in a range of pharmaceutical and biomedical applications, including bone regeneration and tissue bulking. Gels, pastes, fibers and solid structures of alginate are being evaluated for use in numerous tissue-engineering applications. The best known technology is immobilization of living cells in alginate gels. Such bioreactor systems are currently being developed for the treatment of a variety of diseases.

Alginate is a linear copolymer with homopolymeric blocks of (14)-linked b-D-mannuronate (M) and its C-5 epimer -L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks.

The monomers can appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks), alternating M and G-residues (MG-blocks) or randomly organized blocks [1-4]. The relative amount of each block type varies with the origin of the alginate.

Alternating blocks form the most flexible chains and are more soluble at lower pH than the other blocks. G-blocks form stiff chain elements, and two G-blocks of more than 6 residues each form stable cross-linked junctions with divalent cations (e.g. Ca2+, Ba2+, Sr2+ among others) leading to a three-dimensional gel network [5, 6].

At low pH, protonized alginates will form acidic gels. In these gels, it is mostly the homopolymeric blocks that form the junctions, where the stability of the gel is determined by the relative content of G-blocks [7].

Determination of primary structure is today possible by NMR techniques by analyzing the spectrum using appropriate statistical considerations [8, 9].