Tissue engineering is an interdisciplinary field which applies the principles of engineering and the life sciences to the design, construction, modification, growth and maintenance of living tissues [1, 2]. One of two approaches can be taken: (1) in vitro construction of bioartificial tissues from cells seeded onto a resorbable scaffold or (2) in vivo modification of cell growth and function to stimulate tissue regeneration [2, 3]. This concept represents a shift in emphasis from replacement to regeneration of diseased or damaged tissues, in which the development of bioactive materials has played a significant role.This paper will begin with an overview of the use of biomaterials as implants and their limitations, leading to the reasons for the dramatic shift in focus regarding the approach to repairing damaged tissues. The majority of the paper will discuss the ways in which biomaterials can be developed to implement the concept of tissue engineering. Finally, the implications of these developments for future treatment of damaged or diseased tissues will be considered. (C) 2003 Kluwer Academic Publishers.