Alkaline biodegradable implants for osteoporotic bone defects-importance of microenvironment pH
Alkaline biodegradable implants for osteoporotic bone defects-importance of microenvironment pH
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碱性可生物降解植入物治疗骨质疏松性骨缺损——微环境 pH 值的重要性
DOI：
10.1007/s00198-015-3217-8
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发表时间：
2016-01-01
影响因子：
4
通讯作者：
Lu, W. W.
中科院分区：
文献类型：
--
作者：
Liu, W.;Wang, T.;Lu, W. W.
可生物降解植入物引起的微环境pH值的总体变化可能改善骨质疏松性骨重塑的失衡。本研究表明，弱碱性条件刺激成骨细胞分化，同时抑制破骨细胞生成。在体内，具有碱性微环境pH值（通过pH微电极监测）的植入物对骨质疏松性骨缺损的修复显示出良好的愈合效果。
引言
在骨质疏松条件下，骨微环境对骨内植入物的反应显著受损，这大大增加了骨折、骨不连和无菌性植入物松动的风险。酸碱平衡是影响骨细胞行为的一个重要因素。本研究旨在研究一系列碱性可生物降解植入材料对骨质疏松性骨缺损再生的影响，并随时间监测微环境pH值（微环境pH，mu e - pH）。
方法
在不同pH条件下检测骨质疏松大鼠骨髓基质细胞和RAW 264.7细胞的增殖和分化潜能。将去卵巢大鼠的骨缺损用特定的可生物降解材料填充，并用pH微电极测量mu e - pH。分别通过戈尔德纳三色染色和抗酒石酸酸性磷酸酶（TRAP）染色检测新骨样组织和抗酒石酸酸性磷酸酶阳性的破骨细胞样细胞。使用能量色散X射线光谱（EDX）线性扫描研究植入物和新骨之间的中间层。
结果
在体外，弱碱性条件刺激骨质疏松大鼠骨髓基质细胞（oBMSC）分化，同时抑制破骨细胞形成。在体内，mu e - pH不同于均匀的外周血pH值，并且随时间因材料而异。较高的初始mu e - pH与更多的新骨形成、抗酒石酸酸性磷酸酶阳性破骨细胞样细胞的延迟反应以及体内中间“磷灰石”层的形成相关。EDX表明，即使在术后9周，残留材料仍可能影响mu e - pH。
结论
pH微电极适用于体内mu e - pH检测。碱性可生物降解材料在体内产生高于正常生理值的微环境pH值，并且在骨质疏松性骨缺损修复中显示出良好的愈合效果。
SummaryChange of microenvironment pH by biodegradable implants may ameliorate unbalanced osteoporotic bone remodeling. The present work demonstrated that a weak alkaline condition stimulated osteoblasts differentiation while suppressed osteoclast generation. In vivo, implants with an alkaline microenvironment pH (monitored by a pH microelectrode) exhibited a promising healing effect for the repair of osteoporotic bone defects.IntroductionUnder osteoporotic conditions, the response of the bone microenvironment to an endosseous implant is significantly impaired, and this substantially increases the risk of fracture, non-union and aseptic implant loosening. Acid-base equilibrium is an important factor influencing bone cell behaviour. The present purpose was to study the effect of a series of alkaline biodegradable implant materials on regeneration of osteoporotic bone defect, monitoring the microenvironment pH (μe-pH) over time.MethodsThe proliferation and differentiation potential of osteoporotic rat bone marrow stromal cells and RAW 264.7 cells were examined under various pH conditions. Ovariectomized rat bone defects were filled with specific biodegradable materials, and μe-pH was measured by pH microelectrode. New osteoid and tartrate-resistant acid phosphatase-positive osteoclast-like cells were examined by Goldner’s trichrome and TRAP staining, respectively. The intermediate layer between implants and new bone were studied using energy-dispersive X-ray spectroscopy (EDX) linear scanning.ResultsIn vitro, weak alkaline conditions stimulated osteoporotic rat bone marrow stromal cells (oBMSC) differentiation, while inhibiting the formation of osteoclasts. In vivo, μe-pH differs from that of the homogeneous peripheral blood and exhibits variations over time particular to each material. Higher initial μe-pH was associated with more new bone formation, late response of TRAP-positive osteoclast-like cells and the development of an intermediate ‘apatitic’ layer in vivo. EDX suggested that residual material may influence μe-pH even 9 weeks post-surgery.ConclusionThe pH microelectrode is suitable for in vivo μe-pH detection. Alkaline biodegradable materials generate an in vivo microenvironmental pH which is higher than the normal physiological value and show promising healing effects in the context of osteoporotic bone defects.