Foreword

During the last two decades there have been many studies demonstrating the responses of cells of mesenchymal origin (osteoblasts, chondrocytes, fibroblasts, etc.) to mechanical stimulation. However, due to the use of various experimental methods, it has become difficult to compare the research data. Many studies implement the variations of the method of cyclic mechanical stimulation via stretchable membranes onto adherent cells, but other methods exist as well. To compare the data from different experimental methods the mechanical stimulation should be characterized by its displacement, frequency and acceleration (or by the wave shape of the applied force), but in most of the studies neither all this information nor even the common stimulation parameters for cells activation are apparent.

The previous data demonstrate that cellular deformation affects the cytoskeleton, which results in the activation of a cascade of secondary messengers that stimulate metabolic or proliferative response, i.e. mechanotransduction pathways. Unfortunately standardized biomechanical protocols for the optimal in vitro mechanical stimulation of cells are lacking. This standardization should provide all the essential biomechanical information, such as an exact specification of a mechanical force applied, and, if it is cyclic, the mechanical profile specifications should be given. Additionally information on the cell deformation is required. If this information will be provided the optimal parameters of the mechanical stimulation will be determined and the presently existing controversy regarding these parameters will be at least partially settled. This will open the opportunity for the future more effective and comparable studies for determination of the intracellular mechanisms involved in cellular mechanotransduction. However presentation of the current data and knowledge, which are derived from different biomechanical experimental methods of the cellular mechanotransduction research, should also contribute to the communication in this expanding research field.