Zhao Daoli, Wang Tingting, Kuhlmann Julia, Dong Zhongyun, Chen Shuna, Joshi Madhura, Salunke Pravahan, Shanov Vesselin N, Hong Daeho, Kumta Prashant N, Heineman William R
Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA.
Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.
Acta Biomater. 2016 May;36:361-8. doi: 10.1016/j.actbio.2016.03.039. Epub 2016 Mar 30.
Monitoring the biodegradation process of magnesium and its alloys in vivo is challenging. Currently, this process is monitored by micro-CT and X-ray imaging in vivo, which require large and costly instrumentation. Here we report a simple and effective methodology to monitor the biodegradation process in vivo by sensing H2 transdermally above a magnesium sample implanted subcutaneously in a mouse. An electrochemical H2 microsensor was used to measure the biodegradation product H2 at the surface of the skin for two magnesium alloys (ZK40 and AZ31) and one high purity magnesium single crystal (Mg8H). The sensor was able to easily detect low levels of H2 (30-400μM) permeating through the skin with a response time of about 30s. H2 levels were correlated with the biodegradation rate as determined from weight loss measurements of the implants. This new method is noninvasive, fast and requires no major equipment.
Biomedical devices such as plates and screws used for broken bone repair are being developed out of biodegradable magnesium alloys that gradually dissolve when no longer needed. This avoids subsequent removal by surgery, which may be necessary if complications arise. A rapid, non-invasive means for monitoring the biodegradation process in vivo is needed for animal testing and point of care (POC) evaluation of patients. Here we report a novel, simple, fast, and noninvasive method to monitor the biodegradation of magnesium in vivo by measuring the biodegradation product H2 with an electrochemical H2 sensor. Since H2 rapidly permeates through biological tissue, measurements are made by simply pressing the sensor tip against the skin above the implant; the response is within 30s.
监测镁及其合金在体内的生物降解过程具有挑战性。目前，该过程通过体内微型计算机断层扫描（micro-CT）和X射线成像进行监测，这需要大型且昂贵的仪器设备。在此，我们报告一种简单有效的方法，通过在皮下植入小鼠体内的镁样品上方经皮传感氢气（H₂）来监测体内生物降解过程。使用电化学H₂微传感器测量两种镁合金（ZK40和AZ31）以及一种高纯度镁单晶（Mg8H）在皮肤表面的生物降解产物H₂。该传感器能够轻松检测到低水平（30 - 400μM）透过皮肤的H₂，响应时间约为30秒。H₂水平与通过植入物失重测量确定的生物降解速率相关。这种新方法是非侵入性的、快速的，且不需要大型设备。
用于骨折修复的诸如钢板和螺钉等生物医学装置正由可生物降解的镁合金开发而成，当不再需要时这些合金会逐渐溶解。这避免了后续可能因出现并发症而进行的手术取出。动物测试和患者床边护理（POC）评估需要一种快速、非侵入性的方法来监测体内生物降解过程。在此，我们报告一种新颖、简单、快速且非侵入性的方法，通过使用电化学H₂传感器测量生物降解产物H₂来监测体内镁的生物降解。由于H₂能迅速透过生物组织，只需将传感器尖端按压在植入物上方的皮肤上即可进行测量；响应时间在30秒内。
