Cells are able to sense and respond to mechanical stimuli occurring in their microenvironment via mechanotransduction, the intracellular process through which mechanical forces are converted into biological response. A disruption in the ability to properly respond to mechanical stimulations results in a pathologic condition, including osteoporosis, developmental disorders, arthritis and cancer. Cyclic substrate deformation and fluid shear stress are the most widely studied mechanical stimuli involved in cells. Since the in vivo environment is the combination of these mechanical stimulations, the aim of this project is the development of a novel experimental device for simultaneous application of substrate deformation and fluid shear stress in vitro, allowing us to further investigate the cell mechanotransduction process in a better controlled cell culture environment for several pathological conditions. The system will be constituted by an uniaxial stretching device incorporated with a fluid silicone path in a stretch chamber, in which the cells to be tested will be seeded. The stretching system will be designed to induce a controlled cyclic stimulation in a large range of amplitude and frequency to the stretch chamber, incorporated into the fluid path, through the displacement of a linear actuator. The fluid silicone path will be developed by using a 3D printed mold and will be connected to a controlled syringe pump to regulate the flow rate. The entire system will be controlled by specific software for the synchronization of the two mechanical stimuli and it will be accurately characterized for a complete range of stimulation parameters. At last, the proposed system will be employed to study the effects of combined mechanical signals on human Osteosarcoma cell lines with different features. The morphological and biological changes of the treated tissue following the mechanical treatments will be analysed.
Recently, the development of new in vitro platforms designed ad-hoc for the study of the cellular mechanotransduction has become of great interest in different areas of application. One of the main advantages of these systems is the possibility to simulate the mechanical loads involved in the in vivo cell microenvironment in a more controlled cell culture system, allowing us to study the effects of loading on specific cell types during their growth and development and at specific stages of the differentiation process. Moreover, it has to be remarked the important role of the mechanotransduction process in different pathologies. For this reason, molecules that mediate mechanotransduction may represent future targets for therapeutic intervention in a variety of diseases. Insights into the mechanical basis of tissue regulation also may lead to development of improved medical devices, engineered tissues, and biomimetic materials for tissue repair and reconstruction. At last, combined mechanical signals systems can be used like a platform to study pathological conditions in which cells can show altered biological responses to mechanical forces with respect to the healthy cells ones.
In this context, we will develop an experimental system for simultaneous applications of combined mechanical signals in vitro, characterized by an accurate measurement and control of the stimulation parameters occurring on cells.
The proposed system will be designed to have different innovative aspects. First of all, it will be able to induce two combined mechanical stimulations on cells in vitro allowing us to simulate a cellular microenvironment closer to that found in vivo, in order to have a more comprehensive understanding of the cellular mechanotransduction process. Moreover, it will be a versatile platform to study the role of the mechanotransduction in different types of cells, such as bone, skeletal, cardiac and endothelial cells. To reach this aspect, the stimulation parameters will be accurately characterized in a wide range of amplitude and frequency. In view of the possible applications of combined stimulations for a long time, the system will be developed with a compact size and low mass to be easily moved inside the incubator.
Therefore, the proposed study will have an important impact in the field of the mechanotransduction, and will contribute to elucidate deep aspects of the cellular mechanobiology in different pathologies.