Tissue engineering

India's Department of Biotechnology has decided to give a big push for research in "tissue engineering" aimed at eventually creating human organs in a dish apparently for overcoming the problems of donor organ shortages.

The Department has invited "concept proposals" from Indian scientists for regeneration of heart, liver, pancreas, skin, tooth, eye and bone -- complete with muscle, tendon and marrow -- in the laboratory.

The Department announcement says the above were "candidate" organs for development but scientists may propose for funding any other organ for regeneration "provided there is a clear credible evidence for such a choice".

Tissue engineering is a multi-disciplinary field which evolved from the field of biomaterial development. It refers to the practice of combining scaffolds, cells and biologically active molecules into functional tissues.

Tissue engineering can perhaps be best defined as the use of a combination of cells, engineering materials, and suitable biochemical factors to improve or replace biological functions, according to Wikipedia.

Cells are the building blocks of tissue, and tissues are the basic unit of function in the body. Generally, groups of cells make and secrete their own support structures, called extra-cellular matrix.

This matrix, or scaffold, does more than just support the cells; it also acts as a relay station for various signaling molecules. Thus, cells receive messages from many sources that become available from the local environment.

Each signal can start a chain of responses that determine what happens to the cell. By understanding how individual cells respond to signals, interact with their environment, and organize into tissues and organisms, researchers have been able to manipulate these processes to mend damaged tissues or even create new ones.

The goal of tissue engineering is to assemble functional constructs that restore, maintain, or improve damaged tissues or whole organs. Artificial skin and cartilage are examples of engineered tissues that have been approved by the FDA; however, currently they have limited use in human patients.

Regenerative medicine is a broad field that includes tissue engineering but also incorporates research on self-healing – where the body uses its own systems, sometimes with help foreign biological material to recreate cells and rebuild tissues and organs.

The terms “tissue engineering” and “regenerative medicine” have become largely interchangeable, as the field hopes to focus on cures instead of treatments for complex, often chronic, diseases, writes www.nibib.nih.gov.