Figure 2. Hydrogel formulation and modulation of mechanical and degradation properties.

(a) Composition of sulfated alginate hydrogels. (b) Initial moduli of sulfated alginate can be regulated by varying the concentration of ionic crosslinkers. A 3 mM BaCl₂ and 100 mM CaCl₂ concentration produced a hydrogel with low initial modulus, and 6 mM BaCl₂ and 200 mM CaCl₂ produced a high initial modulus. The moduli for 1% oxidized (c) low initial moduli, and (d) high initial moduli decreased to similar levels by day 14. Increasing the oxidation percentage of the MVG alginate from 1% to 5% caused the day 14 moduli to decrease further for (e) low and (f) high initial moduli groups without affecting initial moduli. Data are mean ± SD (n=7–12). Groups with statistically significant differences do not share the same letters.