In vivo monitoring the biodegradation of magnesium alloys with an electrochemical H₂ sensor

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• 作者：Daoli Zhao^a ; Tingting Wang^a ; Julia Kuhlmann^a ; Zhongyun Dong^b ; Shuna Chen^b ; Madhura Joshi^c ; Pravahan Salunke^c ; Vesselin N. Shanov^d ; Daeho Hong^e ; Prashant N. Kumta^e ; ^f ; ^g ; William R. Heineman^a ; ^{William.Heineman@uc.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Biodegradation ; Magnesium alloys ; Electrochemical sensor ; Hydrogen sensor ; Hydrogen ; Gas cavity
• 刊名：Acta Biomaterialia
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：36
• 期：Complete
• 页码：361-368
• 全文大小：1071 K

文摘

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 (30–400 μM) permeating through the skin with a response time of about 30 s. 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.

Statement of Significance

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 30 s.