Hyaluronic acid-based materials for bone regeneration: A review

The healing of bone and cartilage injuries is complex and difficult. Currently, commercially available autogenous and allogeneic bone grafts often fail to meet all clinical requirements. Therefore, the need for effective and methodical treatments has motivated efforts to develop various bone tissue engineering techniques. The design of a successful bone graft requires both mechanical properties that match injury site tissues and biological properties to support stem cell activities, such as differentiation, migration, and mineral deposition. Osteoinductivity can also be achieved by the system itself, loaded drugs, growth factors, or even all of them combined. Composite hydrogel systems have been proven to be mechanically strong, biocompatible, biodegradable, and can be used in combination with several cells, scaffolds, and drugs to promote osteogenesis. Creating such composite scaffolds often requires the utilization of combination of natural polymers, synthetic polymers, and bioceramics at a micro or nanoscale. Hyaluronic acid (HA), a natural polymer found in the human body, is often used to stimulate extracellular matrix microenvironments to promote cell activities such as adhesion and proliferation. Furthermore, HA is capable of cross-linking with other polymers and entrapping drugs/growth factors to achieve controlled release. This review reports the recent efforts in developing HA and modified HA hydrogel systems for in vitro/vivo applications in bone tissue engineering.