Cells are the smallest independently functioning living entities, relying on nutrients and creating waste. Each cell performs a specific function, and the cells of the body work together as building blocks of larger systems.
Although each type of cell is different, there are many similarities among them. With a few exceptions, most cells within the human body have a multitude of organelles that perform required functions, including the cell membrane, nucleus, ribosomes, lysosomes, mitochondria, endoplasmic reticulum, and Golgi apparatus. Understanding how cells function is important for bioengineering, especially the growing area of tissue engineering.
Most cells within the body are continuously being replaced and this process enables the body to heal itself. However, age, injury, disease, and congenital defects can interfere with or halt that process. Regenerative medicine researchers are pioneering ways to engineer artificial tissues from living human cells to overcome these limitations. Tissue-engineered products already in use include human skin and a material developed from pigs called small intestinal submucosa, which aids in wound healing and ligament repair. One promising approach consists of creating a decellularized extracellular matrix in the shape of the desired tissue. This scaffolding would be implanted with human stem cells originally extracted from the person for whom the artificial tissue is being created, and then placed in a bioreactor, a temperature-controlled device that bathes the cells in nutrients and provides mechanical forces to encourage the stem cells to differentiate into functioning tissue cells. When the tissue is adequately developed, it would be surgically implanted into the body of the patient with the hope that it will continue to develop and integrate with the body into a fully functional body part.
Other important work at the intersection of cellular biology and engineering is the genetic modification of cells to enhance desirable traits. Genetically-engineered algae is being developed for enhanced biofuel production.
Bacteria has already been genetically modified through recombinant DNA to produce human insulin. This safe and inexpensive genetically engineered hormone has been available since it was first licensed in 1982.
