Cell responses to physical forces, and how they inform the design of tissue-engineered constructs for bone repair: a review

The fields of biomaterials and bone tissue engineering continue to grow, due in part to new advances in materials science but also to the increasingly broad understanding of how the human body responds to implanted materials. For a long time the goal of the biomaterials scientist was to develop materials that supported healing and were biocompatible, but over time a better understanding of how the body responds to implanted materials has been achieved. The concept of mechanotransduction, which involves mechanical forces applied to the cell, the conversion of those forces into a biochemical signal, the transmission of signals to cells, and the resulting cell response, has blossomed over the past 20 years or so. Here we review how cells, specifically those of the skeletal system, respond to different types of physical forces, how these responses manifest themselves as changes and adaptations within the skeletal system, and how investigators go about evaluating these responses in the laboratory. We also review how these approaches and lessons learned inform the development of novel strategies for bone tissue engineering, toward healing bone defects with biomaterials.