Surface Modification of β-TCP with Stearic Acid and Its Effects on β-TCP/PLLA Biodegradable Composite Nanofibers

Abstract

In order to improve interfacial compatibility between beta-tricalcium phosphate (β-TCP) with poly-L-lactide (PLLA) to prepare bone tissue engineering (TE) scaffold material, a surface modification of β-TCP with stearic acid was investigated. Interfacial interaction between β-TCP particles with stearic acid was studied using Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analyzer (TGA) and X-ray Photoelectron Spectra (XPS). The unmodified β-TCP/PLLA and modified β-TCP/PLLA composite nanofiber membranes with different quality ratios were prepared by electrospinning. Morphology of these composite nanofiber membranes was observed by using scanning electron microscope (SEM). Mechanical properties of these composites were also tested. The results indicated that hydrogen ions of stearic acid produced protonation reaction with oxygen ions in phosphate of β-TCP and then generated hydroxyls. The β-TCP particles modified by stearic acid reduced the agglomeration of β-TCP particles in matrix and obtained continuous and uniform nanofibers. The mechanical properties of the modified β-TCP/PLLA composite nanofiber membranes were significantly improved than those of unmodified β-TCP/ PLLA composite nanofiber membranes.