Wound dressings made from the calcium salt of alginic acid, prepared as a textile fibre and presented as a loose 'rope' or packing for cavities, a ribbon for narrow wounds or sinuses, and a flat non-woven pad for application to larger open wounds. When in contact with serum, wound exudate or solutions containing sodium ions, SORBSAN's insoluble calcium alginate is partially converted to the soluble sodium salt, and a hydrophilic gel is produced. The gel overlays the wound and provides a micro-environment that is believed to facilitate wound healing.