A Digital Image Correlation based technique to control the development of a skeletal muscle engineered tissue by measuring its surface strain field

X-MET (Ex-vivo Muscle Engineered Tissue) is a promising 3-dimensional model of skeletal muscle for in vitro tests and in vivo transplant. X-MET is an in vitro cultured tissue and has several properties in common with adult skeletal muscle, from biological and morphological to functional ones. To monitor the X-MET´s growing improvements, we developed an experimental system based on Digital Image Correlation (DIC) to precisely measure the tissue´s contractile capability, thus trying to prevent the formation of any anisotropic or inhomogeneous parts. We employed a high speed camera mounted on a stereomicroscope, and synchronized the image acquisition with the electrical stimulation and the force response measurement. The capability of measuring the 2-dimensional surface strain field in any desired Region Of Interest (ROI) allowed to obtain a comprehensive monitoring of the tissue´s formation, both at a global and a local level. Preliminary results confirmed the adequacy of the system to measure tissue´s strain field in complete accordance with the force measurement. Moreover, an in-depth analysis allowed to precisely pinpoint the sub-zones where discontinuities arise during tissue formation, returning essential information to improve X-MET generation process.