Biomaterials are defined as man-made materials which have been designed to induce a specific biological activity . These materials can be further classified as biotolerant, bioinert and bioactive .
With the rapid expansion of this field, non man-made materials are increasing used in the biological environment. We choose to broaden the definition of biomaterials to include natural materials as well as tissues.
These are man-made materials that are compatible with the human body. Examples include polyurethane, polyethylene, certain alloys, glass and ceramics.
These are non-man-made materials which are also biocompatible. Examples include silk worm silk and cellulose.
Tissues, whether they are derived from animal or human sources, can also be regarded as a form of biomaterial.
One of the major reasons of studying biomaterials is for the fabrication of medical devices which can be applied to the external (e.g. wound dressing) or internal (e.g. dental & orthopaedic implants, heart valve) of the human body. These devices can be made of synthetic biomaterials (e.g. polyurethane wound dressing, bioceramics bone & dental implants), natural materials (e.g. silk suture) or tissue-synthetic hybrids (e.g. bioprosthetic heart valve).
One important property of some biomaterials is their ability to release bioactive molecules in a controlled manner. This property, when used in combination with a medical device, results in highly valuable products in the healthcare system (e.g. anti-inflammatory coated stent).
field of tissue engineering exploits living cells in a variety of ways
to restore, maintain, or enhance tissues and organs . This is a very
attractive alternative to the use of synthetic materials or tissue
derived from animals or human sources. In most cases it requires the use
of a degradable scaffold for the tissue to form into a desired,
pre-determined shape. The end result is the creation of LIVING medical