Universal and biocompatible hydroxyapatite coating induced by phytic acid-metal complex multilayer.

As the basic component of natural bone in the human body, hydroxyapatite is widely used in orthopedic, dental, and bone implants, especially as a surface coating to improve osteoconductivity and osseointeration of materials. Several methods have been used for hydroxyapatite coating, including plasma spraying, laser pulse deposition, and electrophoretic and electrochemical deposition. However, these methods require expensive instruments and involve complex operations. Thus, it is highly desirable to develop a feasible, simple, cheap, and universal method to prepare hydroxyapatite coatings. In this work, we develop a method for hydroxyapatite coating on various materials by a phytic acid-metal complex multilayer. The abundant phosphate moieties on phytic acid not only work for chemical modification of a wide range of materials but also for further the formation of hydroxyapatite. The formed crystals improve the biocompatibility and osteogenic ability of MG63 cells. This method is simple, cheap, and novel, and can be utilized in biomedical applications such as orthopedic, dental, and bone implants.