生物骨移植材料的灭菌

Sterilization of bio-active bone graft

目的 为寻找用于骨移植材料灭菌的最佳方法和途径 .对比研究环氧乙烷 (EO)及γ射线对生物骨移植材料的灭菌方法及其对诱导成骨活性的影响 .方法 以金葡菌繁殖体、枯草杆菌黑色变种芽胞及蜡样杆菌芽胞 3种标准菌株定量污染复合 BMP的重组合异种骨 (RBX) ,分别做各剂量组6 0 Co-γ射线辐照及 EO气体灭菌试验 ,计数残存活菌 .同时将上述 RBX植入小鼠股部肌袋内 ,做异位成骨活性实验 ,术后7,1 4 ,2 1 ,2 8d取材 ,检测生成组织碱性磷酸酶 (AKP)及钙(Ca)含量 ,并常规做组织学切片 .结果 EO及γ射线均有较强的灭菌效果 ,金葡菌在 EO中 0 .5 h或 γ射线辐照 3k Gy即可完全灭菌 .两种芽胞菌抗性较大 ,EO2 0 0 0 mg· h· L- 1 的消毒强度可完全杀灭 ,而 γ射线辐照则需 40 k Gy以上剂量 .EO及γ射线对诱导成骨活性影响呈一剂量依赖关系 ,小的消毒剂量对移植骨生物活性无明显影响 ,但当 γ射线辐照 2 0k Gy以上或 EO消毒 2 5 0 0 mg· h· L- 1 以上时 ,对诱导成骨活性均有不良影响 .结论 环氧乙烷比γ射线有更快更强的灭菌效果 ,安全范围大 ,完全杀菌的 γ射线辐照剂量 (40 k Gy)也同时完全破坏了骨移植物的成骨诱导活性 ,而完全灭菌的EO剂量对成骨活性干扰小 .中等剂量的 EO消毒即质量浓度 5 0 0 mg· L-

AIM To assure the safety and effectiveness of the bio active bone graft in its clinical use and to search for a better way to sterilize bone graft, this paper has compared the sterilization effect of gaseous ethylene oxide (EO) and cobalt 60 γ radiation on reconstituted bone xenograft (RBX). METHODS The bone chips were contaminated with 107 per milliliter bacteria of Staphylococcus Aureus ATCC 25923, Bacillus Subtilis globigii 8017 and Bacillus Cereus 4001 and then sterilized with various doses of gaseous EO or cobalt 60 γ radiation. The bacteriocidal capacity was determined and theosteoinductive properties were studied by analyzing the bone histomorphology and by evaluating the alkaline phosphatase activity and calcium content of heterotopic ossification after implanting RBX into a muscle pouch in the mouse. RESULTS Both EO and cobalt 60 γ radiation had strong microcidal properties. The S. aureus were fully sterilized by EO after 0.5 hour or by γ radiation at 3 kGy and the two kinds of bacilli were killed by 2000 mg·h·L -1 EO or by 40 kGy γ radiation. The bone inductive properties were reduced in a dose dependent manner and were reduced significantly when sterilized by EO or γ radiation with a dosage of more than 2500 mg·h·L -1 or 20 kGy. CONCLUSION EO has a stronger germicidal capacity and a wider safety range than γ radiation. The radiation of full bacteriocidal doses destroyed the bone induction properties completely while EO doesn't. Moderate doses of EO are preferable in sterilizing particulate bioactive bone grafts, for they possess full bacteriocidal properties but only little interference with the osteoinductive potential.