Hydroxyapatite (HA) and Alginate Combination as Bone Graft Substitute for Bone Defect – A Literature Review

Background: Bone defects refer to the loss or absence of bone matrix. A critical-sized bone defect is defined as a defect large enough that the bone is unable to heal spontaneously without intervention, making it remains a significant challenge for healthcare professionals. According to the diamond concept of bone healing (osteogenic cells, scaffolds, growth factors and mechanical stability), bone substitutes are an important component for bone defects treatment. Autografts remain the gold standard for treating bone defects; however, the development of biomaterials combining ceramics and polymers has emerged as a promising alternative for bonegraft substitutes. The combination of hydroxyapatite as a ceramic and alginate as a polymer has shown promising results in both in vitro and in vivo studies, demonstrating favorable mechanical and biological properties. To further enhance its osteogenic potential, additional research is needed—either by optimizing the current combination or by incorporating growth factors or mesenchymal stem cells.