<P> Calcium alginate is used in different types of medical products including skin wound dressings to promote healing and can be removed with less pain than conventional dressings . </P> <P> Alginate may be used in a hydrogel consisting of microparticles or bulk gels combined with nerve growth factor in bioengineering research to stimulate brain tissue for possible regeneration . In research on bone reconstruction, alginate composites have favorable properties encouraging regeneration, such as improved porosity, cell proliferation, and mechanical strength, among other factors . </P>

____ are a source of algin a product that humans use in cosmetics and ice cream