ABSTRACT
BACKGROUND: Nano-hydroxyapatite has been widely used as reconstructive and prosthetic material for osseous tissue, owing to its excellent biocompatibility and bioactivity. But, its brittleness is one of the most serious obstacles for its wider applications as load-bearing implants. Therefore, hydroxyapatite/chitosan composites have been widely studied as bone substitute, due to their excellent biocompatibUity and suitable mechanical properties.OBJECTIVE: To review various preparation methods of hydroxya patite/chitosan composites and the development trend in this field.METHODS: Articles were searched in Medline Database (1995-01/2009-03), VIP Database (1995-01/2009-03) and "qinghuatongfang" Database (1995-01/2009-03) with the keywords of "nano-hydroxyapatite, chitosan, preparation, development trend".RESULTS AND CONCLUSION: Total 2 034 related articles were collected, including 1 634 in Chinese and 670 in English. Following excluding earilier published, duplicate, and similar studies, we brought into 37 sub-standard literatures. Hydroxyapatite/chitosan composite in nanometer size, with similar structure as natural bone, has better biological function compared with corresponding micrometer composite. Simultaneously, optimized material composition, structure and technology will obtain more suitable bone substitute in mechanical property compared with natural bone. This paper reviews preparation methods at home and abroad in recent years, with the rapid development of biological materials, hydroxyapatite compositematerials have been wisely used in bone tissue repair and replacement surgery, but its poor mechanical properties limits its clinical application.