In this study, bioactive hydroxyapatite nanoparticles were prepared by two different methods: wet chemical precipitation and biomimetic precipitation. The aim was to evaluate the morphology, particle-size, crystallinity and phases of the powders obtained by traditional wet chemical precipitation and the novel biomimetic precipitation using a supersaturated calcium solution. The nanoparticles were investigated by transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The results revealed that the nanoparticles were formed by hydroxyapatite with a high crystallinity and controlled morphology. Additionally, it was found that the shape and size of the nanoparticles can be modified with each preparation method.

En este trabajo se prepararon cementos óseos acrílicos de poli(metacrilato de metilo) (PMMA) modificados con 30, 55 y 80 % en peso de dos tipos de hidroxiapatita: CORALINA® Porosa HAP-200 y nanopartículas de hidroxiapatita con un tamaño promedio de 66 ± 7 µm y 57 ± 4 nm respectivamente. Las nanopartículas de hidroxiapatita se sintetizaron mediante precipitación química por vía húmeda y fueron caracterizadas mediante Espectroscopia Infrarroja, Difracción de Rayos X y Microscopia Electrónica de Transmisión. Las formulaciones fueron sometidas a ensayos mecánicos estáticos, obteniéndose valores máximos de resistencia a compresión axial y a tracción de 95,5 ± 0,9 MPa y 32,4 ± 0,1 MPa respectivamente. Se evidenció que a medida que aumenta el contenido de relleno inorgánico en los cementos disminuyen los valores de ambas propiedades en comparación con un cemento convencional. Las formulaciones que contienen un 55 y 80 % de relleno presentaron resultados satisfactorios de temperaturas máximas de polimerización, pues las mismas no excedieron los 90 ºC

In this work, acrylic bone cements of polymethyl methacrylate (PMMA) were prepared. The formulations were modified with 30, 55 and 80 % in weight of two types of hydroxyapatite: CORALINA® Porous HAP-200 and hydroxyapatite nanoparticles with an average size of 66 ± 7 µm and 57 ± 4 nm respectively. Hydroxyapatite nanoparticles were synthesized by a wet chemical precipitation and were characterized by infrared spectroscopy, X-ray diffraction and transmission electron microscopy. The formulations were subjected to static mechanical testing, obtaining maximum values of axial compressive strength and tensile strength of 95.5 ± 0.9 MPa and 32.4 ± 0.1 MPa respectively. The study showed that with increasing the cement inorganic filler content, both values of mechanical properties diminished in comparison with a conventional cement. The formulations containing 55 and 80 % filler showed satisfactory results in the polymerization temperatures, since they do not exceed 90 ºC