The effect of chelation of sodium alginate with osteogenic ions, calcium, zinc, and strontium

Alginates are attractive in tissue regeneration due to their similarity to the extracellular matrix, biocompatibility, biodegradability, non-antigenicity, and the ability to undergo ionotropic gelation. Alginate hydrogels are formed by ionic crosslinking mainly using calcium ions with some reports on the use of strontium and zinc ions. Strontium and zinc ions in trace amounts are known to accelerate bone healing due to their role in regulating osteoblasts and osteoclasts in addition to their antibacterial properties. This study reports the effect of forming alginate hydrogel films using three different ionic species, Ca 2+ , Zn 2+ and Sr 2+ with different M/G ratios on their physical properties as a method of introducing these ions in alginate composites for bone tissue engineering. The results reveal that mechanical and thermal properties of alginate films along with their water sorption behaviour are affected by the type of ions that crosslink them and the relative amounts of M and G length of the different block structures influence the gel forming ability. Since calcium, zinc and strontium are ions of interest due to their osteogenic properties, the results of this study can be used to tailor the properties of alginates for the development of composite scaffolds for bone tissue regeneration.