Study on Preparation of n-HA and Silk Fibroin Bio-mineral Material

A new hydroxyapatite(n-HA)-Silk fibroin(SF) bio-mineral material was prepared by using a biomimetic method,with Ca(NO3)2 and Na3PO4 used as the starting reagent to synthesize the inorganic phase.In details,SF was dissolved in Ca(NO3)2 solution without desalting procedure,the compound solution was directly dropped into Na3PO4 solution.In this way,HA was synthesized at 37℃ by controlling Ca/P ratio,meanwhile the minerialized HA interacted with SF to form biomineral material.The morphology and structure of this n-HA-SF biomineral material were characterized by XRD,FTIR,XPS and SEM.The results show that there are strong chemical interaction between n-HA and SF.Moreover,in the biomineral material,the inorganic phase is calcium-deficient hydroxyapatite,containing a small amount of carbonated HA with an average crystal size of 37.6nm.In addition,The particle size of biomineral materials range from 50nm to 200nm.It can be deduced that silk fibroin chain can regulate the growth and morphology of HA crystals.The compressive strength of the biomineral material is 32.21MPa,which is a good potential material for bone tissue engineering and unloaded-bearing bone defects repairing.