Fast Escape of Hydrogen From Gas Cavities Around Corroding Magnesium Implants.pdf 由于存在许多优点，作为生物可降解材料金属镁被广泛关注。但由于金属镁降解过程中可释放氢气，在植入物周围可形成气泡，这种情况已经被广泛报道。但是关于这种气泡内的气体成分并不十分清楚，只有 60 年前少数研究采用并不十分精确的技术检测过这种气体的成分（那个年代不会已经有这种材料吧），现在已经有许多先进技术可以精确测定气体中的成分。为明确这种气体的成分，本研究采用氢气电极和质谱技术分别检测氢气浓度。 连续 10 天的检测结果发现，即使在气泡形成早期，这种气泡中氢气的浓度非常低。这意味着氢气在形成气泡后迅速和周围气体发生交换。为确认这种推测，采用氢气直接皮下注射，结果发现在注射后 1 小时大部分氢气都被交换置换（气体中氢气浓度下降），这一结果纠正了这一领域长期的一种认为在金属镁植入物周围是氢气气泡的错误看法。这一研究也有更广泛的意义，过去在潜水医学中，氦氧潜水减压病在形成气泡后，可能发生快速的气体成分交换。而在氢气气泡在氢气成分降低后气体总量没有相应下降，这给直接注射氢气治疗疾病带来一定麻烦，因为气泡的消失速度比较慢，可能对局部组织带来长期影响，当然也可以给使用氢气带来更多联想，例如可以将一种气体释放装置安装到体内，制造出一种长期按照程序给氢气的器材。 Fast Escape of Hydrogen From Gas Cavities Around Corroding Magnesium Implants Julia Kuhlmanna, a Department of Chemistry, University of Cincinnati, PO Box 210172, Cincinnati, OH 45221-0172, USA Magnesium materials are of increasing interest in the development of biodegradable implants as they exhibit properties that make them promising candidates. However, formation of gas cavities after implantation of magnesium alloys is widely reported in literature. The gas composition and the concentration of in these bubbles are not clearly known as only a few studies using techniques not specific for were done about 60 years ago. Currently, many researchers assume that these cavities contain primarily hydrogen because it is a product of magnesium dissolution in aqueous media. In order to clearly answer this question, we implanted rare earth containing magnesium alloy disks in mice and determined the concentration of hydrogen gas for up to ten days using an amperometric hydrogen sensor and mass spectrometric measurements. We were able to directly monitor the hydrogen concentration over a period of ten days and to show that the gas cavities only contained a low concentration of hydrogen gas, even shortly after the formation of the cavities. This means that hydrogen must be exchanged very quickly after implantation. To confirm these results, hydrogen gas was directly injected subcutaneously and most of the hydrogen gas was found to exchange within the first hour after injection. Overall, our results disprove the common misbelief that these cavities mainly contain hydrogen and show how quickly this gas is exchanged with the surrounding tissue.
标签: 植入物
