The beneficial properties of seaweed in the treatment of wounds have since long been known to folk medicine and it is possible that its application goes even back to the dim and distant prehistoric times. There is documented evidence that seaweed used to be collected by seafarers before battles to serve as dressing material. When technological progress facilitated the production of fibres from alginic acid, the properties of the material in promoting wound healing were also specifically tested and confirmed. Pioneer work in this respect was in particular contributed in the forties by George Blaine, a major of the British Army Medical Corps, by means of animal experiments and clinical investigations. In addition to positive effects on wound healing several authors also reported hemostyptic activities of alginates.
Alginic acid is a linear polysaccharide made from two different monomer subunits.
The monomers are mannuronate and guluronate, the gel-forming properties of the respective alginates are mainly determined by the proportional content and distribution of these two components. The ratio of mannuronic acid to guluronic acid may vary to a certain extent, depending on the origin and species of the algae, the part of the plant utilized, and also on the season of harvesting. Through careful selection of the algae feedstock it is, nevertheless, possible to produce alginates of always constant properties. The manufacturing process of alginates involves crushing and washing of the raw material and dissolution of the extracted sodium alginate in water. A viscous solution is obtained which is extruded into a calcium chloride bath.