The calcification potential of cryogel scaffolds incorporated with various forms of hydroxyapatite for bone regeneration

Cryogels are advantageous scaffolds for bone regeneration applications due to their high mechanical stability and macroporous structure. Anatomically, bone is composed of collagen and hydroxyapatite and during remodeling, these structural components are replaced. However, early forms of mineralization include calcium salts which take up to months to be converted to the desired hydroxyapatite form. Thus, it is beneficial to provide a primary source of hydroxyapatite within the scaffold, expediting the process of mineralization during bone regeneration. In this study, chitosan-gelatin (CG) cryogels were incorporated with various forms of hydroxyapatite to evaluate effects on the standard characteristics of cryogels, as well as the potential for increased mineralization. Testing included the comparison of porosity, swelling, mechanical integrity, cellular infiltration, and mineralization potential between all types of cryogels. The addition of bone char to CG cryogels produced scaffolds with appropriate porosity and interconnectivity. Additionally, the bone char cryogels exhibited an adequate swelling potential, suitable mechanical properties, excellent cell attachment, and increased mineralization. These properties support this cryogel for such an application in tissue engineering.