Hydrogel is a commonly used material for encapsulation due to its capability to absorb large amount of water
or biological fluids. Among many materials, calcium-alginate hydrogel is the most widely used due to several
advantageous features such as non-toxicity, biocompatible, easily produced; thermally and chemically stable [6].
Solutions of alginate can be cross-linked by a mild gelling reaction with calcium ions to form a hydrogel. Alginate
gel structure is relatively stable at acidic pH, but it is easily swollen and disintegrated under mild alkali conditions
[7].