The Role of the Host Immune Response in Tissue Engineering and Regenerative Medicine

Tissue engineering and regenerative medicine-based approaches commonly employ a combination of scaffolds, cells, and bioactive molecules. Regardless of the approach used for each clinical application, the objective is the same; specifically, the restoration of structure and function. Similarly, regardless of which strategy is selected, the response of the host to the implanted construct will dictate the success or failure of the eventual outcome. It is unlikely that the host response can be avoided and, therefore, designs which incorporate an in-depth understanding of the host immune response together with other requisite criteria will likely meet with improved success and downstream functionality. The present chapter briefly reviews the default mechanisms of wound healing, the foreign body response to non-degradable permanent implants, and the host response to various strategies employed within tissue-engineered constructs. Particular emphasis is placed upon newly defined paradigms surrounding the host macrophage response.