Strontium‐substituted biphasic calcium phosphate microspheres promoted degradation performance and enhanced bone regeneration

Abstract

Biphasic calcium phosphate (BCP) ceramics are the subject of much attention for use as bone replacement material. However, it remains a challenge to promote the degradation and osteoinductivity performances of BCP ceramics. In this work, novel BCP ceramic microspheres with good degradation and excellent osteoinductivity were prepared through high-content strontium (Sr) doping. The in vitro results indicated that the Sr10-BCP, Sr40-BCP, and Sr80-BCP microspheres all had their HA crystals partially transformed to the beta tricalcium phosphate phase following high-temperature sintering because of Ca-deficient HA formed by the partial substitution of Ca ions by Sr ions. In addition, the degradation rate was increased with the doping of increasing amounts of Sr. All prepared microspheres enhanced human bone marrow-derived mesenchymal stem cells attachment and proliferation. Specifically, among these modified microspheres, the Sr40-BCP microspheres showed the highest osteogenic potential. Furthermore, Sr40-BCP and HA microspheres were implanted in a calvarial defect model of rat to evaluate the in vivo bone augmentation ability. The results indicated that Sr40-BCP microspheres degraded more completely and significantly promoted new bone regeneration compared with HA microspheres. In conclusion, Sr40-BCP microspheres have excellent potential for degradation and bone regeneration and are promising osteogenic materials. K E Y W O R D Sbiphasic calcium phosphate, bone regeneration, degradation, microspheres, strontiumsubstituted

Octacalcium Phosphate for Bone Tissue Engineering: Synthesis, Modification, and In Vitro Biocompatibility Assessment

“…Cells of 7–10 passages were used in the experiments. The cells were planted in 96-well plates (SPL life science, Pocheon, Korea) at a concentration of 1.5 × 10 4 cells/cm 2 , cultured for 24 h and then added to OCP and OCP-Sr at concentrations of 10.00, 3.33, 1.11, 0.37, 0.12, 0.04, and 0.01 mg/mL and were co-cultured for another 96 h. OCP and OCP-Sr samples were pre-sterilized with 75% ethanol according to the indicated method [ 48 ].…”

“…Cells were grown in Basal Medium Eagle (Sigma-Aldrich, Milwaukee, WI, USA) supplemented with heat-inactivated fetal bovine serum (Gibco, Waltham, MA, USA) to a final concentration of 10% and 2 mM L-glutamine (Sigma-Aldrich, St. Louis, MO, USA), 40 µg/mL gentamicin sulfate (Sigma-Aldrich, St. Louis, MO, USA), under conditions of 5% CO 2 content in the air and at 37 • C. Cells of 7-10 passages were used in the experiments. The cells were planted in 96-well plates (SPL life science, Pocheon, Korea) at a concentration of 1.5 × 10 4 cells/cm 2 , cultured for 24 h and then added to OCP and OCP-Sr at concentrations of 10.00, 3.33, 1.11, 0.37, 0.12, 0.04, and 0.01 mg/mL and were co-cultured for another 96 h. OCP and OCP-Sr samples were pre-sterilized with 75% ethanol according to the indicated method [48].…”

Biodegradable Inorganic Nanostructured Biomaterials for Drug Delivery

“…For example, Chen et al. [ 165 ] reported enhanced degradation and osteoinductivity of biphasic calcium phosphate ceramic microspheres by high‐content Sr 2+ ion doping. They found that the degradation rate of materials increased with increasing doping amount of Sr 2+ ions, and 40% Sr 2+ ‐doped sample degraded more completely and significantly promoted new bone regeneration compared with HAP microspheres.…”

Enhanced ectopic bone formation by strontium-substituted calcium phosphate ceramics through regulation of osteoclastogenesis and osteoblastogenesis

“…Thus, many material modification techniques have been applied to improve the physico-chemical properties of CaP ceramics in order to further enhance their bioactivity and osteogenic capacity. 3,4 In recent years, extensive studies on ion doping have been performed to introduce a variety of bioactive ions into CaP ceramics, such as magnesium (Mg), 5 zinc (Zn), 6 and strontium (Sr). 7 Among these ions, Sr has attracted great interest due to its unique chemical and biological properties.…”