快速有效的促进骨再生仍然是临床治疗各种骨疾病的一大挑战。虽然近年来开发的电活性材料显示出了较高的骨再生潜能，但电刺激的不稳定性和电荷极性对成骨分化的影响尚不明确，阻碍了其临床应用。2020年，南方医科大学邵龙泉教授首次利用极性可控的GaN/AlGa材料诱导出内源性电场促进骨再生。通过控制功能层中压电和自发极化的方向和大小，得到了极性相反、zeta电位在生理电位范围内的带电GaN/AlGaN表面。与N-极性的GaN/AlGaN相比(表面带正电荷)，Ga极性GaN/AlGaN(表面带负电荷)纳米膜在体内显示出快速和良好的骨修复效果。此外，Ga极性GaN/AlGaN异质结构显著促进骨间充质干细胞在体外的附着、扩散、募集和成骨分化。此外，骨形态发生蛋白-6（BMP6）在成骨分化早期的表达谱表明，BMP6可能是一种电敏感的成骨蛋白。本研究对Ⅲ族氮化材料在骨再生中的应用具有重要意义。

Rapid and effective bone regeneration is still a major challenge in the clinical treatment of various bone diseases. Although recently developed electroactive materials have demonstrated high bone regeneration potential, the instability of the electrical stimulation and the unclear effects of the charge polarity on osteogenic differentiation hinder their clinical applications. In this work, GaN/ AlGaN materials with well-controlled polarity are used for the first time to induce endogenous electric stimulation and facilitate bone regeneration. By controlling the direction and magnitude of the piezoelectric and spontaneous polarization in the functional layer (GaN), charged GaN/AlGaN surfaces of opposite polarity, whose zeta potentials are within the range of the physiological potential, are obtained. Compared with N-polarity GaN/AlGaN (with a positively charged surface), Ga-polarity GaN/AlGaN (with a negatively charged surface) nanofilms show rapid and superior bone repair in vivo. In addition, the Ga-polarity GaN/AlGaN hetero-structures significantly promote the attachment, spreading, recruitment, and osteogenic differentiation of bone mesenchymal stem cells in vitro. Moreover, the bone morphogenetic protein-6 (BMP6) expression profile in the early stages of osteogenic differentiation reveals that BMP6 may be an electrically sensitive osteogenic protein. This work sheds light on the application of III-nitride materials in bone regeneration.

DOI:10.1016/j.cej.2020.126203

（王鹏）