Nano-hydroxyapatite surfaces grafted with electroactive aniline tetramers for bone-tissue engineering.

An electroactive amino/carboxyl-capped aniline tetramer (AT) is covalently grafted to the surface of hydroxyapatite (HA) nanoparticles to generate novel electroactive HA-AT nanoparticles. The amount of AT ranges from 16.5 to 34.0 wt% and is characterized by thermogravimetric analysis (TGA). The HA-AT nanoparticles are characterized by Fourier transform IR (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction, and scanning electron microscopy (SEM). For the excellent electroactivity of HA-AT, the mixture of HA-AT and PLA shows much better adhesion ability and proliferation ability than that of HA and a PLA matrix. At a 15 wt% AT grafting amount, the matrix shows the best biocompatibility.