Generation of Silk Fibroin-Ca-P Composite Biomimetic Bone Replacement Material Using Electrochemical Deposition

Abstract

Mineralized natural protein based novel bone replacement materials are investigated for tissue engineering. Mineralized silk fibroin composite foams and films display excellent biocompatibility. In this study, the biomimetic and electrochemical mineralization of orderly oriented silk fibroin scaffolds was studied. Commercially obtained pure silk woven fabric was boiled in 0.02 M Na2CO3 for 20 min. Calcium phosphate was deposited at 37 degrees C for twenty minutes in seven sequential immersion steps, using 250 mM CaCl2 2H(2)O and 120 mM K2HPO4, containing 0.15 M NaCl and 50 mM TRIS-HCl, pH 7.4, followed by electrochemical treatment in modified SBF solution at 40 degrees C at a current density of -25mA/cm(2) for 60 min. The amount of biomimetically deposited Ca-P increased with the number of immersion steps. SEM images and XRD analysis of the Ca-P deposit indicated the initial formation of brushite with its monoclinic crystal structure and characteristic peak at 11.76 2 theta, and electrochemical conversion of brushite to hydroxyapatite on silk after electrochemical cathodization as confirmed by XRD and SEM analysis. Thus, a silk-fibroin-hydroxyapatite composite material prepared as a xenograft consisting of biocompatible components, and easily prepared as an economical bone segment replacement material with highly oriented fibers.