Читать книгу Materials for Biomedical Engineering - Mohamed N. Rahaman - Страница 21

Since antiquity, the conventional approach to repairing diseased or damaged tissues or organs in the body has been to replace them with transplanted tissues or organs, or with durable synthetic implants composed of metals, ceramics or polymers. While this approach has worked well, it suffers from limitations related to factors such as supply of donor tissue or organs, or the inadequate lifetime of the implanted biomaterial. A radical shift in this conventional approach was proposed approximately three decades ago. Instead of focusing on repairing or replacing tissues and organs with transplanted tissues or organs, or with durable materials, this new approach, referred to as tissue engineering, is based on regenerating functional tissues and organs. A definition of the term is:

“Tissue engineering is an interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function” (Langer and Vacanti 1993).

The tissue engineering approach involves harvesting cells, incorporating them into a suitable biomaterial, and stimulating them ex vivo (outside the body). Then the resulting construct is implanted into the patient at the appropriate time. Alternatively, the cell‐seeded biomaterial can be implanted directly into the body (Chapter 25). More recently, the term regenerative medicine has been used to describe a broader approach to regenerating the patient’s own tissues or organs. Regenerative medicine includes tissue engineering as well as two other approaches based on cell therapy and gene therapy. Biomaterials form an important component of the tissue engineering approach, whereas cell therapy and gene therapy involve biomaterials only minimally.