Optimization and validation of a mechanical stimulation system for pathological in vitro models of cardiac tissue

Cardiovascular diseases (CVD) refer to diseases affecting the heart and blood vessels, and they pose a significant health challenge with substantial morbidity and mortality on a global scale. It is important to note that CVDs are the leading cause of death worldwide. At the same time, the process of discovering and developing drugs is a challenging one, and current methods for evaluating drug safety and efficacy are both costly and inefficient: only 13.8% of drugs make it into phase I trials. One of the fundamental factors contributing to this challenge is the limited predictive accuracy of commonly employed preclinical research models: in vivo animal models. In addition, the choice of animal model should be carefully considered because it affects the experimental results and the ability of the study results to be translated into humans. Finally, it is important to consider the ethical implications of using animal models. In this context, the development of in vitro pathological cardiac models that best represent the conditions in humans is essential. To achieve this, a system has been developed to apply mechanical stimulation to engineered heart tissues (EHTs). The use of this device is advantageous for replicating pathological conditions such as those related to the cardiac preload phase and heart rate abnormalities. The device can fit inside an incubator and all parts can be custom made using 3D printing as manufacturing techniques. Furthermore, EHTs technology and usage of standard 24 well plates, allow to replicate the same conditions on 24 samples simultaneously. In this work, the device functioning was optimized to obtain greater stability and a more homogeneous deformation of each well in the well plate. After that, an analysis method was developed using MATLAB to evaluate the stretching percentage for each well, by analyzing video recorded during stimulation of the supports for the cardiac models. In the final phase of the project, cellular tests were performed. The EHTs were stretched for 7 days and the force produced by them was measured with a video-based optical analysis. After 7 days of stimulation, the culture media was analyzed to assess the presence of specific peptides produced by cells in case of heart stress, volume-related issues and myocardial damage.