Real-time monitoring of mechanical cues in the regenerative niche reveal dynamic strain magnitudes that enhance bone repair

Abstract

Mechanical loads exerted on the skeleton during activities such as walking are important regulators of bone repair, but dynamic biomechanical signals are difficult to measure inside the body. The inability to measure the mechanical environment in injured tissues is a significant barrier to developing integrative regenerative and rehabilitative strategies that can accelerate recovery from fracture, segmental bone loss, and spinal fusion. Here we engineered an implantable strain sensor platform and measured strain across a bone defect in real-time throughout rehabilitation. We used the sensor to longitudinally quantify mechanical cues imparted by a load-sharing fixation plate that significantly enhanced bone regeneration in rats. We found that sensor readings correlated with the status of healing, suggesting a potential role for strain sensing as an X-ray-free healing assessment platform. This study demonstrates a promising approach to quantitatively develop and exploit mechanical rehabilitation strategies that enhance bone repair.