Tissue engineering involves the use of a combination of cells, biomaterials, and biochemical agents, and aims to generate tissue samples that can improve or replace biological functions. The two main components of tissue engineering are:
- Cells - cells are the building blocks of tissue, while tissues are the functional units in the body. Cells for tissue engineering are typically grown in vitro (i.e. in the laboratory), on a biodegradable and biocompatible carrier (either a matrix or a scaffold). The cells and the matrix constitute a functional construct capable of restoring, maintaining, or improving damaged tissues or whole organs.
- Matrix - The matrix, or scaffold, is designed not only to support cell growth, but also to respond to biological stimuli, release impregnated therapeutic growth factors and interact with the tissue environment to induce regeneration processes.
Tissue engineering often begins with construction of a scaffold from a wide set of possible sources. Then, cells are introduced to the scaffold, in the presence or absence of growth factors - substances known for their remarkable regeneration properties. When culture conditions are appropriate, a tissue forms.
In some cases, the cells, scaffold component and growth factors are all mixed together, allowing the tissue to “self-assemble”. Following transplantation, the proliferating cells and growth factors within the graft stimulate natural repair mechanisms in the defective tissue.
The goal of tissue engineering is therefore to cure rather than treat, complex, often chronic, conditions.
Tissue engineering holds great promise for applications involving patients' own (autologous) cells, and for the generation of customized, compatible tissues and organs capable of repairing incurable diseases and tissue deficiencies.