Advances in Porous Scaffold Design for Bone and Cartilage Tissue Engineering and Regeneration

Tissue engineering of bone and cartilage has progressed from simple to sophisticated materials with defined porosity, surface features, and the ability to deliver biological factors. To avoid eliciting a foreign body response due to inclusion of allogeneic cells, advances in functional scaffold design harness the endogenous ability of the body to regenerate. We review advancements in the surface and structural properties of typical polymeric, ceramic, and metallic scaffolds for orthopedic use. First, we provide an overview of methods and materials, with a focus on additive manufacturing and electrospinning. Multidimensional physical properties of scaffolds, including three-dimensional macrostructure, pore design, and two-dimensional hierarchical surface roughness, allow tissue regeneration at different spatial and temporal scales. Enhanced biological response can be achieved through surface functionalization and the use of exogenous factors. Finally, different in vitro and in vivo models are discussed for translation of these technologies for clinical use.