Wireless Magnetoelasticity-Based Sensor for Monitoring the Degradation Behavior of Polylactic Acid Artificial Bone In Vitro

Abstract

A magnetoelasticity-based (MB) sensor was employed for monitoring the degradation behavior of polylactic acid (PLA) artificial bone (PAB) in vitro, which can be used as an implant to repair bone defects. Biodegradable PLA material was coated on both sides of the MB sensor strip with a 3D printer, forming PAB. The PAB samples were submerged in an alkaline medium (pH = 12) and a neutral phosphate-buffered saline (PBS) medium (pH = 7.4). The degradation behavior of the PAB was monitored wirelessly based on changes in the output power of the MB sensor. The results indicated that the output power varied by almost 0.2 and 0.11 dbm over 15 days in the two media. The degradation behavior monitored by the MB sensor agreed with the theoretical analysis. The MB sensor provides a wireless method for monitoring the degradation behavior of PAB in vitro and requires few samples at a lower cost. Importantly, the results showed that biological tissues had almost no effect on the monitoring function of the MB sensor. Therefore, the MB sensor technology is highly attractive for fully characterizing the degradation behavior of bone implants in a larger range of physiological conditions, and will be applied to monitor the degradation behavior in vivo.