Schematic illustration of the two-component alginate system and the method of gel formation. The system consists of an aqueous sodium alginate solution (A), and insoluble strontium or calcium alginate particles dispersed in an aqueous medium (B). The individual components reside in each of two syringes connected with a three-way connector (C). Upon mixing, gelling ions migrate from the strontium or calcium alginate particles (D). A reciprocal migration of non-gelling ions associated with the soluble alginate also takes place. The gelling ions coordinate with binding sites on two adjacent chains (E) and a gel is formed.