The Effect of Y2O3 on Properties of Hydroxyapatite Thin Films Prepared by Pulsed Laser Deposition

HA and HA+Y2O3 films were prepared by pulsed laser deposition. The microstructure and composition of films were studied by EPMA, XRD, AFM and SEM. In vitro study was performed by immersing the sample in simulate body fluid (SBF) in different days. There are more droplets on films prepared by HA+Y2O3 target than that of HA. And addition of Y2O3 can decrease the size of crystal grains. The XRD results show that the peaks corresponding to HA slightly shift to lower angel which indicates the HA lattice distorting due to addition of Y2O3. The critical load of the films increases from 10.3N to 13N when Y2O3 added. The film prepared by target HA+Y2O3 shows a higher resistance to dissolution and the precipitated grain size is small. New precipitated phases have similar functional groups with the original films.

Novel Composite of Nano-Sized SiO2/Chitosan Induce the Growth of HAp Crystal

A novel hybrid material of chitosan/nano-sized SiO2/hydroxyapatite (HAp) composite was prepared through a biomimetic approach. HAp deposited in situ on the surface of chitosan/ nano-sized SiO2 composite film in simulate body fluid (SBF) solution at 36.5°C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study composition and morphological characteristics of the HAp crystal. The results indicated that nano-sized SiO2 dispersed in the chitosan film provided initial nucleation sites for the growth of the HAp in SBF solution by adsorbing further PO4 3−, Ca2+ due to the induction of HAp formed. The strength of the composite was largely improved because of the addition of nano-sized SiO2.

Hydroxyapatite Formation on Cellular Alumina Coated with Bioactive Glasses

Various works have been done to produce a cellular form of bioactive ceramics for a scaffold. However, the most of these cellular implants have low compressive strength. In this study, therefore, glass-infiltrated cellular alumina with compressive strength of 7.3MPa was first prepared. Bioactive glass was then coated on the cellular alumina. When the specimen was reacted in simulate body fluid, hydroxyapatite developed on the bioactive glass coat in 18 hours.