Subpixel Texture Correlation for Contractile Behaviors of Engineered Cardiac Tissue

Tissue engineering of cardiac patches has offered a great potential to provide replacement for damaged or diseased myocardium, especially with recent progress in cardiovascular differentiation of embryonic stem cells [1] and dynamic culture of cardiac constructs with electrical field and perfusion [2, 3]. Spontaneous beating is one of most important characteristics of cardiac tissue, and contractile responses under electrical field are often treated as ‘golden standard’ for evaluating engineered cardiac patches. Therefore, it is necessary to accurately measure their contractile behaviors. However, till now, in most of previous studies, the observation of cardiac contraction has been relied on naked eyes, and functional assessments of those constructs have therefore been difficult and very time-consuming.