The scaffold is made from several different materials, depending on the type of cells doctors need to grow. The most popular material is a biodegradable polymer. These "plastics" gradually dissolve in the body as new tissue develops and no longer needs support. Biomedical engineers also build the scaffolds out of hydroxyapatite, which is a mineral present in bone, or collagen, which is a material that makes up skin.

Scientists impregnate the scaffold with cells. The choice of cells depends on the tissue to be regenerated - osteoblasts for bone, chondrocytes for cartilage and endothelial cells for blood vessels.

The cells rapidly multiply and begin to form new tissue, blood vessels or bone. The scaffold serves as a support structure for the cells and dissolves gradually as the cells produce tissue.