Maazouz Yassine, Chizzola Giacomo, Döbelin Nicola, Bohner Marc
RMS Foundation, Bischmattstrasse 12, 2544, Bettlach, Switzerland.
RMS Foundation, Bischmattstrasse 12, 2544, Bettlach, Switzerland.
Biomaterials. 2021 Aug;275:120912. doi: 10.1016/j.biomaterials.2021.120912. Epub 2021 May 28.
Some synthetic bone graft substitutes (BGS) can trigger ectopic bone formation, which is the hallmark of osteoinduction and the most important prerequisite for the repair of large bone defects. Unfortunately, measuring or predicting BGS osteoinductive potential based on in vitro experiments is currently impossible. A recent study claimed that synthetic BGS can induce bone formation ectopically if they create a local homeostatic imbalance during their in vivo mineralization. This raised the hope that a simple cell free in vitro mineralization experiment would correlate with osteoinduction. The aim of the present study was therefore to assess the ability of a quantitative in vitro mineralization test to predict and rank the osteoinductive potential of BGS. Eight calcium phosphate BGS already tested ectopically in 9 different in vivo studies were used for that purpose. The experiment was able to identify materials that are reliably osteoinductive from those that are not, but was inaccurate in ranking the osteoinductive materials between each other. Chemical contaminants (Ca, Mg, H, OH, PO) present in some of the BGS affected the in vitro mineralization experiment results, but not in a direction that could explain the different rankings. In conclusion, this study suggests that an in vitro experiment can be used as a fast and reliable screening tool to identify osteoinductive BGS and underline the need to study ionic contaminants on calcium phosphate BGS.
一些合成骨移植替代物（BGS）可引发异位骨形成，这是骨诱导的标志，也是修复大骨缺损的最重要前提条件。遗憾的是，目前无法基于体外实验来测量或预测BGS的骨诱导潜力。最近一项研究称，如果合成BGS在体内矿化过程中造成局部稳态失衡，就能够异位诱导骨形成。这让人们燃起了希望，即简单的无细胞体外矿化实验可能与骨诱导相关。因此，本研究的目的是评估定量体外矿化试验预测BGS骨诱导潜力并对其进行排序的能力。为此，使用了已在9项不同体内研究中进行异位测试的8种磷酸钙BGS。该实验能够从非骨诱导材料中识别出可靠的骨诱导材料，但在对骨诱导材料进行相互排序时并不准确。一些BGS中存在的化学污染物（钙、镁、氢、氢氧根、磷酸根）影响了体外矿化实验结果，但影响方向无法解释不同的排序情况。总之，本研究表明体外实验可作为一种快速可靠的筛选工具来识别骨诱导性BGS，并强调了研究磷酸钙BGS上离子污染物的必要性。
