Tissue engineering and regenerative medicine are interdisciplinary fields aimed at developing biological substitutes to restore, maintain, improve tissue function, or replace diseased and damaged tissues. Both hard tissues (e.g., bone, cartilage) and soft tissues (e.g., skin, cardiovascular valves) can be fabricated by tissue engineering. Cells, scaffolds, and growth-stimulating signals are three key components for engineering tissue substitutes. Whereas tissue engineering cultures tissue in vitro, regenerative medicine combines tissue engineering with other strategies, including cell-based therapy, gene therapy, and immunomodulation, to induce in vivo tissue regeneration. Biomimetic tissue constructs are also developed as in vitro models for drug screening and disease modeling.
Tissue engineering involves cultivating new tissue in the lab by combining scaffolds, native tissue cells, and bioactive molecules to emulate the biological processes of the body.
Tissue scaffolds are analogous to the functions of extracellular matrix (ECM) in native tissues. Tissue scaffolds provide a structural and physical environment for cells to grow, migrate, and respond to signals; mechanical properties to the resulting tissue; and bioactive cues to the residing cells for activity regulation.
Three major approaches have evolved to develop tissue scaffolds that mimic native ECM functions: