Figure 2.

Schematic representation of the photopolymerization process of alginate methacrylate. (a) After exposing the polymer solution to ultraviolet radiation, the photoinitiators generated free radicals that react with the vinyl methylene starting the crosslinking reaction; (b) the reaction propagates with macroradicals reacting with unreacted carbon-carbon double bonds. (c) At the end through a bimolecular termination mechanism, a three-dimensional network of the cross-linked hydrogel is formed [30].