Alginates as biomaterials in tissue
engineering
Therese Andersen,” Bent L. Strand,” KjetiI Formo,” Eben Alsberg’
and Bjørn E. Christensen’
DOl: 10.103919781849732765-00227
Alginates comprise a unique — and at the same time - diverse family of
polysaccharides that allows fabrication of a variety of biomaterials suitable
for tissue engineering. This is reflected in a rapidly expanding scientific
literature on the subject, novel regulatory approved products, and on-going
clinical trials. Alginate based biomaterials include gels and fibres for
immobilisation and proliferation of mammalian cells, as well as injectable
solutions and pastes with delayed gelation. The diversity of chemical
compositions [for example high or low content of L-guluronic acid (G)
blocks] as well as control of the molecular weight distribution and mode of
gelation allow precise tailoring of pre-determined biomaterial properties.
Crosslinking of alginate chains may be obtained either by the classical
calcium route, or by covalent crosslinking. Derivatives such as peptide
coupled alginates or periodate oxidised alginates allow enhanced cell
enhancement and proliferation, and enhanced depolymerisation, respec
tively. Recent advances in the study of alginate biosynthesis in bacteria, in
particular the discovery of several processive mannuronan C5-epimerases
with different epimerisation patterns, have provided a remarkable insight
into the compositional heterogeneity of alginates.