8. Development of a Microloading Platform for In Vitro Mechanotransduction Studies

Mechanotransduction studies aim to understand the process of cells converting mechanical stimuli into a cellular response. As it can be difficult to study the impact of isolated factors using in vivo studies, in vitro studies are used as they offer more precisely controlled loads for experiments and allow cell culture on a variety of surfaces. Here, we developed a microloading platform for in vitro mechanotransduction studies, stretching the substrate by tenting it with a centrally contacting platen. This platform works through the use of a load cell and microactuator, which was characterized by comparing the reported and measured displacements. In addition, an alignment block was designed for the microloading platform to increase reproducibility between studies, and a cell culture handling system was designed to hold samples before experimentation and reduce preloads, allowing the study of only the controlled loading. A polydimethylsiloxane (PDMS) scaffold was also designed for cell loading, complete with a positional reference grid for observing the response of individual cells to strain. Initial work with this microloading platform includes studying osteocyte-like MLO-Y4 cells and changes in viability in response to mechanical load in vitro. These initial studies have demonstrated the ability to induce cell death in response to microdamage.