Incorporation of strontium up to 5 Mol. (%) to hydroxyapatite did not affect its cytocompatibility

Abstract

The aim of this work was to produce hydroxyapatite (HA) granules containing 0, 0.5, 1 and 5 mol. (%) of strontium (Sr), evaluate the physico-chemical properties and also the cytotoxicity by three different parameters of cell viability (ISO 10993-5, 10993-12). The physico-chemical characterization was carried out by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and X-ray fluorescence (XRF). The XRD profile presented the main peaks of HA (JCPDS 860740) and the absorption bands of HA were identified by FTIR. The XRF results showed that the strontium concentration was close to the theoretical value. Regarding the cytotoxicity assays, the incorporation of strontium up to 5 mol. (%) to the HA did not affected dehydrogenase activity (XTT, 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide), membrane integrity (neutral red uptake) or DNA contend (incorporation of crystal violet), in relation to HA alone. In conclusion, hydroxyapatite containing from 0.5 to 5 mol. (%) of Sr was successfully produced and presented no cytotoxicity.

Substituted hydroxyapatites for biomedical applications: A review

“…However, Chung and Long [206] proved that coatings with a concentration exceeding 38.9 at.% of Sr significantly inhibit RAW264.7 osteoclast differentiation. Dos Santos Tavares et al [218] revealed that hydroxyapatite containing from 0.5 to 5 mol.% of Sr did not affect dehydrogenase activity, membrane integrity or DNA content.…”

Synthesis and characterization of Sr and Mg-doped hydroxyapatite by a simple precipitation method

“…SrHAP2, [24,25] and the transformation of HAP to β-TCP (tricalcium phosphate) above 700 °C. [26,27] The to pure HAP based on statistical calculation (F and t probes).…”

“…presents that the Ca/P or (Ca+Sr)/P molar ratios are approximately 1.67 in the case of HAPht and SrHAP4 but only 1.42 for SrHAP2. This small ratio would mean the formation of Ca-deficient HAP which decomposes above 700 °C to β-TCP[26,27,32]. As the samples were pure HAP without any other phases, we assume the real value is close to the theoretical 1.67.…”

Microwave-assisted fabrication of strontium doped apatite coating on Ti6Al4V

“…Such phenomenon has been reported in both Sr based drug [20] and Sr doped ceramics [14], although the optimum content of Sr may be different as reported in different doped materials. As reported by Tavares et al, Sr doping at 5 mol% has no cytotoxicity on osteoblasts [21]. In the work of Fu et al, Sr substituted HA containing different Sr concentrations (0%, 1%, 5%, 10%, 100%) have been biologically tested [22,23].…”