Substitution of strontium and boron into hydroxyapatite crystals: Effect on physicochemical properties and biocompatibility with human Wharton-Jelly stem cells

Multisubstituted hydroxyapatite powders and coatings: The influence of the codoping on the hydroxyapatite performances

“…The carried out physicochemical analyses demonstrated that Sr,B‐HAw, obtained by wet method, was composed of nanocrystal apatite structure, whereas Sr,B‐HAd, obtained by dry method, presented microcrystal apatite structure. Between the two different followed processes, the dry method resulted more efficient in promoting the simultaneous strontium and boron incorporation within apatite lattice, revealing higher Sr and B amounts in the Sr,B‐HAd sample than in the Sr,B‐HAw one . Furthermore, Sr 2+ and ions co‐doping led to the modification of a and c parameters of the unit cell, without any significant influence on the crystals morphology.…”

“…Furthermore, strontium was co‐substituted with boron within hydroxyapatite crystals, using two different methods, ie the precipitation method (Sr,B‐HAw) and the dry method (Sr,B‐HAd) . The carried out physicochemical analyses demonstrated that Sr,B‐HAw, obtained by wet method, was composed of nanocrystal apatite structure, whereas Sr,B‐HAd, obtained by dry method, presented microcrystal apatite structure.…”

“…Furthermore, Sr 2+ and ions co‐doping led to the modification of a and c parameters of the unit cell, without any significant influence on the crystals morphology. Moreover, it was evidenced that in Sr,B‐HAw sample boron occurs in the form of ions, which are mostly accumulated on the hydrated surface layer, whereas in Sr,B‐HAd sample both strontium and boron are located inside HAp crystals, substituting Sr ions for Ca ones and B ions,in the form of borate for orthophosphate ions and, in the form of for hydroxyl groups …”

“…Finally, cytotoxicity cells were carried out by Uysal et al, Kolmas et al, Basar et al, Landi et al and Kim et al In details, Uysal et al studied the Saos‐2 cells in vitro viability, proliferation and morphology and highlighted an increment of cell proliferation and ALP due to Zn 2+ (2 mol%) incorporation within apatite lattice and further increase in the case of co‐doping with Zn 2+ (2 mol%) and F − (1 mol%). Thus, the obtained co‐doped particles can be considered promising candidates for biomedical applications, particularly in the case of osteoporosis treatments, due to their enhanced mechanical properties and biological responsiveness.…”

“…Thus, the obtained co‐doped particles can be considered promising candidates for biomedical applications, particularly in the case of osteoporosis treatments, due to their enhanced mechanical properties and biological responsiveness. On the other hand, Kolmas et al investigated the biocompatibility of Sr/B co‐doped hydroxyapatite crystals, by seeding human Wharton‐Jelly stem cells, demonstrating the biocompatibility of all the produced materials. Furthermore, Basar et al analysed the biocompatibility properties of yttrium and fluoride co‐substituted HAp powders ([Y 3+ ] = 2.5, 5.0 and 7.5 mol%), [F − ] = 2.5 mol%), evidencing that the lowest 2.5 mol% Y 3+ and 2.5 mol% F − doped HAp, sintered at 1100°C, was characterised by the highest cell attachment, even if the cell proliferation and bone specific differentiation markers were comparable to those revealed in the case of undoped HAp.…”