Department of Orthopaedic and Spinal Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Biomed Mater Res B Appl Biomater. 2010 Jan;92(1):161-7. doi: 10.1002/jbm.b.31502.
In this study, the effects of gamma-ray irradiation on the mechanical properties, absorbability, and osteoconductivity of porous hydroxyapatite/collagen (HAp/Col) were investigated. Porous HAp/Col was exposed to 16, 25, 35, or 50 kGy of gamma-ray irradiation. The compressive elastic modulus showed irradiation dose-dependence, with a particularly pronounced decrease in the 50-kGy treatment group. An in vitro enzymatic digestion test showed that gamma-ray irradiation of porous HAp/Col resulted in accelerated degradation by collagenase. For in vivo studies, porous HAp/Col was transplanted into the back muscles or bone defects in the femoral condyle of rats. Specimens were obtained at 2, 4, and 8 weeks postoperatively. Absorption of the implants in the muscle was time- and irradiation dose-dependent, with notable absorption for the 35- and 50-kGy groups at 2 weeks. At the skeletal sites, porous HAp/Col demonstrated high osteoconductivity in all irradiation treatment groups. Interestingly, not only implant absorption but also bone formation was irradiation dose-dependent at early time points.
本研究探讨了γ射线辐照对多孔羟磷灰石/胶原（HAp/Col）力学性能、可吸收性和骨引导性的影响。将多孔 HAp/Col 暴露于 16、25、35 或 50 kGy 的γ射线辐照下。压缩弹性模量表现出辐照剂量依赖性，特别是在 50 kGy 处理组中明显降低。体外酶消化试验表明，γ射线辐照多孔 HAp/Col 导致胶原酶加速降解。在体内研究中，将多孔 HAp/Col 移植到大鼠背部肌肉或股骨髁骨缺损中。术后 2、4 和 8 周时获得标本。植入物在肌肉中的吸收与时间和辐照剂量有关，在 2 周时，35 和 50 kGy 组的吸收明显。在骨骼部位，所有辐照处理组的多孔 HAp/Col 均表现出高骨引导性。有趣的是，不仅是植入物吸收，而且早期的骨形成也与辐照剂量有关。
