Progress in composite hydrogels enriched with icariin for bone defect healing

Abstract At present, the repair of severe bone defects caused by trauma, tumors, infection, or congenital diseases is still a significant problem in surgical treatment and one of the major challenges in modern medicine. Many studies have confirmed that bone tissue has a particular self‐repair ability. However, artificial bone substitute materials are still needed to repair large‐area bone defects that exceed their self‐repair ability. Currently, tissue engineering materials that mimic natural bone structure and mechanical and biological properties have been widely used to repair bone defects and promote in situ bone regeneration. Hydrogels with extracellular matrix‐like properties are common bone tissue engineering materials. Among them, hydrogels loaded with bioactive molecules have received widespread attention as an ideal bone replacement material. Icariin, a flavonoid compound extracted from the traditional Chinese medicine Epimedium, has multiple biological activities such as promoting osteogenesis, anti‐bone resorption, and inhibiting inflammation, especially showing great potential in the treatment of osteoporosis. This article reviews the biological functions of icariin, the preparation strategy of hydrogels, and the research progress of icariin‐loaded hydrogels as bone defect repair materials in the field of bone tissue engineering in recent years. The challenges that need to be overcome in applying icariin‐loaded hydrogels in bone tissue repair and the future development trends are also summarized. Highlights The chemical structure and biological functions of icariin were reviewed. The preparation materials and strategies of hydrogels were introduced. The research progress, challenges, and development trends of icariin hydrogel in repairing bone defects were summarized.