| The skeletal system is vital for the support of body. It also serves as the reservoir of calcium and phosphorus, and is crucial for the maintenance of calcium and phosphorus balance. The skeletal tissue contains three types of cells: osteoblasts, osteoclasts and osteocytes. Bone remodeling is an important mechanism for maintaining bone metabolism and mechanical function in adulthood, and disruptions to the balance between bone formation and bone resorption during the remodeling cycle lead to many skeletal diseases, such as osteoporosis, Paget’s disease, and cancer metastases. Skeletal disease is one of the most prevalent chronic diseases, affecting population health, and is a serious public health problem. Due to the characteristic of bone, skeletal diseases can be hard to treat. The targeting and delivery of therapeutic agents to skeletal system provide both a challenge and an opportunity. Targeting drugs to the site of action not only can increase efficacy but also can reduce toxicity. There are two general methods of targeted drug delivery to the bone tissue. The first involves targeting of the entire skeletal system, such as tetracyclines, bisphosphonates, bionic protein and radio pharmaceutical; the second involves targeting drugs to specific cellular locations within the skeletal system. These targets are often either osteoblasts, osteoclasts, osteocytes or bone marrow stromal cells. In this paper, research advances of bone targeted delivery systems have been reviewed. |