Objective:To evaluate the biocompatability of nano-hydroxyapatite crystals and polyamide composite(n-HA/PA66) with the human embryonic fibroblast(HEFs)

to provide an experimental evidence for its clinical application.Methods:The morphological observation was made and pictures of HEFs were taken 1d

2d

4d

and 7d after co-culture with extract of n-HA/PA66

and direct contact with n-HA/PA66.To determine absorbance of every hole under 500 nm with enzyme linked immunity instrument after 1d

2d

4d

and 7d of contact of n-HA/PA66 extract with HEF cells

and direct contact with n-HA/PA66.In the meanwhile calculate the relative multiplication rate of cells

and evaluate them by six degree tests for cytotoxicity.Results:The HEFs in direct contact culture with composite were attached and proliferated well on the materials surface.The growth and proliferation of cultured cells was not significantly inhibited between every composite group with the negative group ( P >0.05).There was significant difference between every composite group with the positive group( P <0.05).In this experiment the toxicity of n-HA/PA66 to HEF cells ranges from zero to one degree.Conclusion:n-HA/PA66 have good biocompatibility with human embryonic fibroblast(HEFs) in vitro

up to the standard of International Organization for Standardization(ISO).