Smart cell culture substrates and smart resorbable orthopedic hardware: Shape memory polymers for basic and applied mechanobiology

In vitro studies have begun to elucidate the principles through which biophysical aspects of extracellular matrix (ECM) behavior support and regulate tissue development, disease, and healing. Engineered 2D and 3D substrates and scaffolds have provided increasingly powerful tools with which to investigate the relationships between cell mechanical behavior and ECM composition and organization. But substrates and scaffolds are often static structures, unchanged over time, providing poor mimics of dynamic in vivo environments. As engineered in vitro environments become more accurate biochemical and biophysical tools for investigating and modeling in vivo environments, the critical next step for many areas of cell biomechanics and mechanobiology will be incorporation of increased programmable physical functionality into the environments. To this end, we have been investigating the use of shape memory polymers for the study and application of mechanobiology. Here we will present ongoing work on programmable cell culture substrates and scaffolds. The results demonstrate control of cell behavior through shape-memory-activated biophysical changes and introduce the use of such substrates and scaffolds for investigation of mechanotransduction, cell biomechanical function, and cell soft-matter physics and for application in tissue engineering and regenerative medicine. Future challenges in controlling and studying smart autonomous materials (mammalian cells) on and in shape-changing substrates and scaffolds will also be discussed.