Tissue engineering is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions. While it was once categorized as a sub-field of bio materials, having grown in scope and importance it can be considered as a field in its own right.

While most definitions of tissue engineering cover a broad range of applications, in practice the term is closely associated with applications that repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, muscle etc). Often, the tissues involved require certain mechanical and structural properties for proper functioning. The term has also been applied to efforts to perform specific biochemical functions using cells within an artificially-created support system (e.g. an artificial pancreas, or a bio artificial liver). The term regenerative medicine is often used synonymously with tissue engineering, although those involved in regenerative medicine place more emphasis on the use of stem cells to produce tissues.

Ali Khademhosseini (born October 30, 1975) is an Iranian-Canadian academic and an Associate Professor at Harvard Medical School, Harvard-MIT Division of Health Sciences and Technology and Wyss Institute for Biologically Inspired Engineering. He has carried out research in the area of biomedical microdevices and biomaterials. He has developed a number of methods for controlling the stem cell microenvironment using microscale devices and to engineer biomaterials for tissue engineering. He has published extensively in the area of biomedicine and stem cell bioengineering. He has over 130 peer-reviewed publications, more than 100 invited presentations and 14 issued or pending patents. He received his PhD in Bioengineering at MIT and his undergraduate and Masters degrees, both in chemical engineering at University of Toronto.