Porous calcium alginate-gelatin interpenetrated matrix and its biomineralization potential

Artificial bone composites exhibit distinctive features by comparison to natural tissues, due to a lack of self-organization and intimate interaction apatite-matrix. This explains the need of "bio-inspired materials", in which hydroxyapatite grows in contact with self-assembling natural polymers. The present work investigates the function of a rational design in the hydroxyapatite-forming potential of a common biopolymer. Gelatin modified through intrinsic interactions with calcium alginate led through freeze-drying to porous hydrogels, whose architecture, constitutive features and chemistry were investigated with respect to their role on biomineralization. The apatite-forming ability was enhanced by the porosity of the materials, while the presence of alginate-reinforced Gel elastic chains, definitely favored this phenomenon. Depending on the concentration, polysaccharide chains act as "ionic pumps" enhancing the biomineralization. The mineralization-promoting effect of the peptide-polysaccharide network strictly depends on the hydrogels structural, compositional and morphological features derived from the interaction between the above mentioned two components.