Tissue engineering, aka regenerative medicine(noun): medicine described as the creation of tissues that provide, repair, replace or restore structures and functions absent or lost due to congenital defects, aging, disease, or damage. In recent years, the Wake Forest Institute for Regenerative Medicine in North Carolina and the Karolinska Institute in Stockholm, Sweden, have succeeded in engineering simple internal human structures like the bladder and the windpipe (Fountain, 2012). Their success has developed largely from the understanding that stem cells can differentiate into other types of somatic cells, which has aided tissue engineers in performing groundbreaking research.
Dr. Tracy Grikscheit, a surgeon who practices in Los Angeles, splits her time between performing intricate pediatric surgeries and running innovative tissue engineering experiments at the Saban Research Institute. Many tissue engineering procedures (such as the windpipe procedure developed at the Karolinska Institute) seek to place plastic scaffolds that are ìseededî with cells into the body to completely replace an internal structure.
Dr. Grikscheit uses a different approach: she seeks to use the patientsí bodies as incubators to help grow their own replacement organs, particularly intestinal tissues (Fountain, 2012).
To test this concept, Dr. Grikscheit cuts healthy intestinal tissue from laboratory rats, mice, and pigs, treats the tissue with enzymes in order to create clusters of cells that include stem cells, and then places the cluster of cells on a porous, plastic scaffold (Fountain, 2012). This procedure is known as ëseeding the scaffold with cellsí.
Although the scaffold is approximately the size of a pencilís eraser, it orients the cluster of cells and helps cells that will form the lining of the tissue grow inward, while cells that will form the outer connective tissue are urged to the outside of the scaffold. This cluster of cells, complete with plastic scaffold, is then implanted back into the animal into a membranous sac of the abdomen called the ëomentumí. Once the cells are implanted into the omentum and provided with nutrients by surrounding blood vessels, the plastic scaffold dissolves, ultimately leaving behind a hollow ball of the animalsí own cells (Fountain, 2012).
However, the remarkable aspect of this hollow ball of cells is that they have the nerves, muscles, blood vessels, and proper intestinal lining that is seen in healthy intestinal tissue. In other words, Dr. Grikscheit and her team have discovered how to take stem cells and differentiate them into healthy tissue.
Although Dr. Grikscheit has also been able to grow human intestinal tissue with the aid of human donor cells, she says that there is a long way to go before testing her procedure on humans is probable (Fountain, 2012). However, she has begun to work on creating a viable procedure for humans, and with the success sheís had so far with laboratory animal and human donor cells, the odds are in her favor.