RESUMO
The aim of the present study was to prepare resorbable hydroxyapatite (HA) based bone graft materials reinforced with carbon nanotubes as a way to cope with the inability of pure HA to resorb and its intrinsic brittleness and poor strength that restrict its clinical applications under load-bearing conditions. With this purpose, a Si-doped HA nanopowder (n-Si0.8HA) was prepared by chemical synthesis and used as composite matrix reinforced with different amounts of functionalized multiwall carbon nanotubes (MWCNTs). The effect of the added amounts of MWCNTs on the mechanical properties of nanocomposites and their in vitro biomineralization was assessed by bending strength measurements, immersing tests in simulated body fluid solution (SBF), scanning electron microscopy (SEM), and inductively coupled plasma atomic emission spectroscopy analysis (ICP-AES). The bioactivity and bending strength were enhanced, reaching maximum balanced values for an optimum addition of 3 wt.% f-MWCNTs. These results might contribute to broaden the potential applications of HA-based bone grafts.
Assuntos
Líquidos Corporais/química , Durapatita/química , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Silício/química , Materiais Biocompatíveis/síntese química , Força Compressiva , Cristalização/métodos , Módulo de Elasticidade , Teste de Materiais , Tamanho da Partícula , Estresse Mecânico , Propriedades de Superfície , Resistência à TraçãoRESUMO
Rod-like hydroxyapatite nanoparticles (n-HAp) with a highly ordered nanostructure were prepared by hydrothermal synthesis from calcium chloride, and phosphoric acid, as calcium and phosphorus sources, respectively. Various surfactant families such as cationic (CTAB), anionic (SDS) and nonionic (Triton X-100) were used as regulators of the nucleation and crystal growth. The synthesized nanopowders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectrograph (FTIR) and transmission electron microscopy (TEM). The rod-like morphology was obtained regardless of the surfactant used during the hydrothermal treatment, but the aspect ratio of the crystals was found to be surfactant dependent. The mechanism of crystal growth as well-oriented nanostructure is discussed.