Tissue Engineering is a multidisciplinary scientific field working on the development of lab grown tissues, such as organs, muscle tissues, or specific cell types, by combining expertise from synthetic biology, molecular biology, biology, chemistry, material science, and mathematics.
The primary objective of tissue engineering is to understand the principles of tissue growth and to apply this to produce functional replacement tissue. Such tissue can be used to restore, maintain, or improve damaged tissues or whole organs. By 2005, engineered artificial skin and cartilage tissues had been approved by the FDA, however had limited use in human patients.
Tissue engineering is a subset of regenerative medicine, a field which deals with the process of replacing, engineering, or regenerating biological units to (re-)establish normal function using the body's self-healing capabilities. Tissue engineering focuses on cures, rather than treatments, for diseases related to biological tissues.
The field is multidisciplinary in nature, requiring collaborations between cell and molecular biology, clinicians, materials scientists, mathematicians, and more. For example, mathematical models are used to form a holistic understanding of complex biological processes in evolving tissues. The combination of biomimetic materials science and stem-cell biology with mathematical models is used to determine which tissue engineering strategies are most likely to be successful. Such an integration of mathematical models with experimentation in an iterative framework where each informs the other offers a way to better understand tissue regeneration.
How it works
Cells are the building blocks of tissues. Groups of cells make their own support structures, called extra-cellular matrices, or scaffolds. Scaffolds mechanically support cells and act as a relay station for various signaling molecules in the body. When a signal is received, it initiates a chain of responses that affect the cell. By better understanding how cells respond to signals, interact with their environments, and organize themselves into tissue and organisms, researchers are able to manipulate these processes to mend damaged tissues or create new ones.
In tissue engineering, a scaffold is built from a variety of sources, ranging from proteins to plastics. Cells are introduced to the scaffold with or without a mix of growth factors, depending on the application. In the right environment, an engineered tissue develops. In this process, the combination of cells, scaffolds, and growth factors produce a self-assembling tissue.
Another method is to use an existing scaffold from the collagen in cells of a donor organ. As of 2013, this method has been used to bioengineer heart, liver, lung, and kidney tissues. By using scaffolding from human tissue discarded during surgery, researchers are exploring ways to use a patient's own cells to make customized organs that will not be rejected by the patient's immune system.