Hydrothermal fabrication of mesoporous carbonated hydroxyapatite microspheres for a drug delivery system

Continuous-flow precipitation as a route to prepare highly controlled nanohydroxyapatite:in vitromineralization and biological evaluation

“…As described above, the prepared HAp has a lower calcium content, suggesting thereby a more negative surface when compared to the commercial HAp [46,47]. Moreover, the lower dimensions (Figures 2 and 3) and the higher surface area (Table 2) of the synthesized HAp particles make them to adsorb more ions on their surface, leading to an increased degree of supersaturation of the surrounding fluid with respect to apatite, and thus accelerating the precipitation process [27,39,48]. The surface reactivity of the synthesized HAp may also be attributed to the existence of adsorbed water on its surface [28], constituting an ion reservoir for the growth of a new apatite phase [49].…”

Structural and microstructural interpretations of Zn-doped biocompatible bone-like carbonated hydroxyapatite synthesized by mechanical alloying

“…The band at 878 cm À1 belongs to the 2 bending vibration of the C-O bonds in the carbonate group, which is characteristic of A-type carbonation in HAp. On the other hand, we did not notice any prominent peak at 3570 cm À1 arising from the stretching vibration of an OH À group (Guo et al, 2012;Zhu et al, 2011;Zou et al, 2012;Rehman & Bonfield, 1997;Chaikina et al, 2009;Ivankovic et al, 2007). This is due to the replacement of OH À by a CO 3 2À group and it confirms the dominance of A-type over B-type carbonation in these HAp samples.…”

“…The doublets present at 563 and 598 cm À1 are derived from the O-P-O bending-mode ( 4 ) vibration. The peak at 958 cm À1 results from the symmetric stretching ( 1 ) vibration of the P-O bonds, while the quite broad peak between 1038 and 1106 cm À1 can be assigned to the P-O asymmetric stretching ( 3 ) vibration (Guo et al, 2012;Zhu et al, 2011;Zou et al, 2012). In all these as-milled samples, there is a relatively broad band in the region 1400-1580 cm À1 due to the 3 stretching vibration of the carbonate group (Rehman & Bonfield, 1997;Chaikina et al, 2009;Ivankovic et al, 2007) which contains three overlapping frequencies of 3 , 1470 and 1550 cm À1 due to A-type carbonation and a small kink at 1419 cm À1 due to B-type carbonation (He et al, 2008(He et al, , 2007.…”

Biodegradable and Biocompatible Systems Based on Hydroxyapatite Nanoparticles

“…Porous HAp particles can be prepared according to a great diversity of methods [11] such as self-assembly [12][13][14][15], spray drying [16], double emulsion [17], solvothermal [18], sol-gel [19] and hydrothermal [20][21][22][23].…”