Research Progress in Calcium Phosphate Microspheres for Bone Defect Repair

Calcium phosphate ceramic microspheres have attracted many research interests in various application fields, such as separation, catalysis, sensor, tissue engineering and drug delivery, due to their excellent permeability, high surface area ratio, low density and stable mechanical properties. In this paper, current advances of calcium phosphate ceramic microspheres in bone regeneration applications, such as bone tissue engineering and anabolic drug delivery, were comprehensively reviewed. Calcium phosphate ceramic microspheres were classified into four main categories according to their solid, porous, hollow or flow-like structures. The corresponding preparation methods and specific applications were summarized. Advantages and disadvantages of such microspheres were evaluated and future improvements were proposed. This review is intended to provide a comprehensive guide to the design and fabrication of calcium phosphate microspheres aiming at repairing bone defects.