Alginate-based hydrogels can find uses in a wide range of applications, including
in the encapsulation field. This type of hydrogels is usually ionically crosslinked
using calcium sources giving rise to products with limited internal crosslinking.
In this work, it is hypothesized that the combination of alginate crosslinked by calcium
chloride (external crosslinking; ionic mechanism) with gelatin crosslinked by transglutaminase
(internal crosslinking; enzymatic induced mechanism) can be used to tailor the swelling
behavior of alginate-based hydrogel microspheres. A systematic study was conducted
by covering process variables such as gelatin content, TGase concentration, and CaCl2
contact time, added by statistic tools as central composite rotatable design (CCRD),
principal component analysis (PCA) and multiobjective optimization, to map their effect
on the resulting water content after production (expressed as swelling ratio), and
swelling properties at pH 3 and 7. Among the studied variables, particle's swelling
was mostly affected by the gelatin content and transglutaminase concentration.