Laboratory for Bone and Implant Sciences (LBIS), The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA.
J Dent Res. 2010 Apr;89(4):411-6. doi: 10.1177/0022034510363243. Epub 2010 Mar 3.
Lack of cytocompatibility in bone substitutes impairs healing in surrounding bone. Adverse biological events around biomaterials may be associated with oxidative stress. We hypothesized that a clinically used inorganic bone substitute is cytotoxic to osteoblasts due to oxidative stress and that N-acetyl cysteine (NAC), an antioxidant amino acid derivative, would detoxify such material. Only 20% of rat calvaria osteoblasts were viable when cultured on commercial deproteinized bovine bone particles for 24 hr, whereas this percentage doubled on bone substitute containing NAC. Intracellular ROS levels markedly increased on and under bone substitutes, which were reduced by prior addition of NAC to materials. NAC restored suppressed alkaline phosphatase activity in the bone substitute. Proinflammatory cytokine levels from human osteoblasts on the bone substitute decreased by one-third or more with addition of NAC. NAC alleviated cytotoxicity of the bone substitute to osteoblastic viability and function, implying enhanced bone regeneration around NAC-treated inorganic biomaterials.
骨替代物缺乏细胞相容性会损害周围骨骼的愈合。生物材料周围的不良生物学事件可能与氧化应激有关。我们假设由于氧化应激，一种临床使用的无机骨替代物对成骨细胞具有细胞毒性，而抗氧化氨基酸衍生物 N-乙酰半胱氨酸 (NAC) 将使这种物质解毒。当在商业脱蛋白牛骨颗粒上培养 24 小时时，只有 20%的大鼠颅骨成骨细胞存活，而含有 NAC 的骨替代物的这一比例增加了一倍。在骨替代物上和下方，细胞内 ROS 水平显著增加，而 NAC 的预先添加降低了这些水平。NAC 恢复了骨替代物中受抑制的碱性磷酸酶活性。添加 NAC 后，人成骨细胞在骨替代物上的促炎细胞因子水平降低了三分之一或更多。NAC 减轻了骨替代物对成骨细胞活力和功能的细胞毒性，这意味着 NAC 处理的无机生物材料周围的骨再生得到增强。
