Sintering of magnesium‐strontium doped hydroxyapatite nanocrystals: Towards the production of 3D biomimetic bone scaffolds

Abstract

The development of biomimetic scaffolds is a challenging aim in the field of bone repair for fabrication of osteoconductive and osteoinductive scaffolds. Biogenic hydroxyapatite (HA) is not stoichiometric but is substituted by several ions. An approach to improve synthetic scaffolds biomimetism can be the doping with osteoinductive ions. To this aim, herein thermally stable magnesium-strontium hydroxyapatite (HAMgSr) nanocrystals were synthesized and used for the fabrication of sintered highly porous scaffolds. The chemical and physical properties of the obtained scaffolds were analyzed by X-ray diffraction, scanning electron microscopy, mechanical testing. Three different substituting ions percentage were analyzed and among these, the copresence of Mg and Sr at 0.5 wt% has shown the best results in terms of thermal stability and mechanical properties. The potential utilization of these materials for bone regeneration purposes was preliminarily evaluated in vitro, by assaying proliferation of viable osteoblast-like cells; the experimental evidences suggest that the scaffolds can be exploited as bone-mimicking substrates suitable to support cell growth and proliferation. These observations underline the importance of the presence of Mg and Sr in scaffolds for bone remodeling as well as the good potential of the newly developed scaffolds for clinical use in tissue engineering. K E Y W O R D Sbone 3, doping 2, hydroxyapatite 1, scaffold 4, sintering 5

Mechanical and Biological Properties of Magnesium- and Silicon-Substituted Hydroxyapatite Scaffolds

“…HA-Mg and HA-Si showed almost similar weight loss around 1.8%. These results imply that Mg and Si ion substitution does not alter the biostability of scaffolds much, since the amount of substitution is very less compared to other works [26][27][28]. To evaluate the biostability, the synthesized scaffolds were immersed in Tris-HCl at 37 °C for different time intervals of 3, 7, 14 and 28 days of immersion.…”

Effects of Strontium-Doped β-Tricalcium Scaffold on Longitudinal Nuclear Factor-Kappa Beta and Vascular Endothelial Growth Factor Receptor-2 Promoter Activities during Healing in a Murine Critical-Size Bone Defect Model

“…Nevertheless, the oral application of strontium ranelate increases the risk of deep venous thromboembolism due to systemic distribution and, therefore, should be avoided in patients with an increased risk of stroke and ischemic cardiac disease [24]. To explore the positive effects of strontium, many reports have focused on the local application of Sr as single-ion substitutions in the scaffolds [54][55][56][57]. We used Sr-doped β-TCP in this study.…”

Research status of biodegradable metals designed for oral and maxillofacial applications: A review

“…Some MgHA particles were integrated by bone, and the residual biomaterial graft particles account for 32.2–38% [ 141 , 148 ]. Recently, MgHA has been applied to produce bone substitutes with excellent biocompatibility and osteogenic activity [ [149] , [150] , [151] , [152] ]. Caneva's team evaluated the performance of small particles of MgHA (Ca 10 -xMgx[PO4] 6 [OH] 2 ; SintLife®, Finceramica, Faenza, Italy) as a bone substitute in the immediate implantation of dog posterior teeth.…”