Tissue Engineering was originally defined by Skalak and Fox, in 1988 as ‘the application of the principles and methods of engineering and life sciences towards the fundamental understanding of structure-function relationships in normal and pathological mammalian tissues and the development of biological substitutes to restore, maintain, or improve functions’.
Later, Langer and Vacanti, in 1993, defined three main pillars of Tissue Engineering principles, the (i) isolated cells and substitutes – cellular systems and cellular products; (ii) tissue-inducing substances – bioactive molecules; and (iii) scaffolds, biomaterials and/or matrices.
Significant progress has been made in stem cells-based Regenerative Medicine, which enables researchers and clinicians to treat those diseases which cannot be cured by conventional treatments. The unlimited self-renewal and multi-lineage differentiation potential to other types of cells and their capacity to produce bioactive molecules and regenerative products, causes stem cells to be frontier in Regenerative Medicine. Researches in Regenerative Medicine have been focused on human and animal cells including embryonic as well as adult stem cells or even somatic cells.
Stem cell therapy has been developed in the last decade. Nevertheless, obstacles including unwanted side effects due to the migration of transplanted cells as well as poor cell survival have remained unresolved. In order to overcome these problems, cell therapy and cell-based therapy has been introduced using biocompatible and biodegradable biomaterials to reduce cell loss and long-term in vitro retention of stem cells. Currently in clinical trials, these biomaterials are widely used in drug and cell-delivery systems, Regenerative Medicine and Tissue Engineering in which to allow the long-term survival and controlled release.