Dr. Langer is often referred to as one of the pioneers of tissue engineering field. As defined by Dr. Langer and Dr. Vacanti, tissue engineering is "an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ." Dr. Langer and his colleagues have made advances such as creation of engineered blood vessels and various vascularized tissue scaffolds on biocompatible and biodegradable synthetic polymers. New skin, muscle, bone, and even entire organs can be grown to help victims of serious accidents or diseases who suffer from missing tissues or nonfunctional organs.