3. Mechanical Stimulation in a PCL Additive Manufacturing Scaffold

Three-dimensional (3D) scaffolds are increasingly employed as support for studies on cellular activities. They are widely shown to enhance cell survival and are a promising approach to be employed to mimic the in vivo conditions due to their controlled architecture. Moreover, 3D stiff structures fabricated by additive manufacturing are able to bear mechanical stimuli finding a role in the investigation of the effect of mechanical forces on cell proliferation and commitment. With this purpose, we propose a combination of a 3D polycaprolactone (PCL) scaffold and collagen soft gel as support for studying the response of mesenchymal stem cells following mechanical compression. This chapter focuses on the characterization of 3D Insert^® PCL scaffolds behaviour under mechanical compression. After defining mechanical properties and variability due to boundary effects, the focus moves on the development of a new composite scaffold made of a stiff PCL structure acting as support for cell activities and able to bear mechanical compression while embedding a soft collagen gel matrix responsible to provide an environment enhancing cellular activities as well as to transmit the stress resulting from the mechanical stimulation from the stiff matrix to the seeded cells. Finally, the last section focuses on the effect of low mechanical strain applied on seeded scaffolds and how the cellular response varies to bursts of compression applied at different time points.