Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Hospital, Technische Universität Dresden, Dresden, Germany.
Acta Biomater. 2013 Jul;9(7):7536-44. doi: 10.1016/j.actbio.2013.03.014. Epub 2013 Mar 20.
The aim of this study was to evaluate two different approaches to obtaining strontium-modified calcium phosphate bone cements (SrCPCs) without elaborate synthesis of Sr-containing calcium phosphate species as cement precursors that could release biologically effective doses of Sr(2+) and thus could improve the healing of osteoporotic bone defects. Using strontium carbonate as a strontium(II) source, it was introduced into a hydroxyapatite-forming cement either by the addition of SrCO3 to an α-tricalcium phosphate-based cement precursor mixture (A-type) or by substitution of CaCO3 by SrCO3 during precursor composition (S-type). The cements, obtained after setting in a water-saturated atmosphere, contained up to 2.2at.% strontium in different distribution patterns as determined by time-of-flight secondary ion mass spectrometry and energy-dispersive X-ray spectroscopy. The setting time of CPC and A-type cements was in the range of 6.5-7.5min and increased for substitution-type cements (12.5-13.0min). Set cements had an open porosity between 26 and 42%. Compressive strength was found to increase from 29MPa up to 90% in substituted S-type cements (58MPa). SrCPC samples released between 0.45 and 1.53mgg(-1) Sr(2+) within 21days and showed increased radiopacity. Based on these findings, the SrCPC developed in this study could be beneficial for the treatment of defects of systemically impaired (e.g. osteoporotic) bone.
本研究旨在评估两种不同的方法来获得锶改性磷酸钙骨水泥（SrCPC），而无需精心合成作为水泥前体的含锶磷酸钙物种，这些前体可以释放出具有生物效应的 Sr（2+）剂量，从而改善骨质疏松性骨缺损的愈合。本研究使用碳酸锶作为锶（II）源，将其引入羟磷灰石形成的水泥中，方法是将 SrCO3 添加到α-磷酸三钙基水泥前体混合物中（A型），或者在制备前体时用 SrCO3 替代 CaCO3（S 型）。在水饱和气氛中凝固后获得的水泥，其锶含量高达 2.2at.%，不同分布模式通过飞行时间二次离子质谱和能量色散 X 射线光谱来确定。CPC 和 A 型水泥的凝固时间在 6.5-7.5min 范围内，而替代型水泥的凝固时间增加（12.5-13.0min）。凝固后的水泥具有 26-42%的开放孔隙率。抗压强度从 29MPa 增加到替代型 S 型水泥的 90%（58MPa）。SrCPC 样品在 21 天内释放出 0.45-1.53mgg(-1) Sr（2+），并显示出增加的射线不透性。基于这些发现，本研究中开发的 SrCPC 可能有益于治疗系统性受损（例如骨质疏松）骨骼的缺陷。
