Regenerative Medicine and the Foreign Body Response

The host response, and in particular the innate immune response, is critical to the successful application of tissue engineering to the reconstruction of injured or missing tissues. Cell-based, scaffold-based, and signal molecule-based strategies are utilized in regenerative medicine and each of these approaches elicits a distinct host immune response that has a significant impact upon the downstream outcome. Modulation, but not suppression of the immune component of wound healing appears to be essential for constructive remodeling of tissues and organs. Promotion of a pro-wound healing and anti-inflammatory response, and avoidance of the foreign body reaction is associated with a constructive functional remodeling outcome. While macrophages play a pivotal role in this response, other immune cells and the interactions between all cell types involved in tissue remodeling are also clearly important. The objective of this chapter is to provide an overview of the host response to biomaterials including both the pro-inflammatory and resultant foreign body reaction, and the pro-wound healing, anti-inflammatory response that is associated with constructive remodeling.