Tissue engineering is one of those old technologies that is still very useful. To carry it out, you build (or harvest) a protein matrix that cells can grow on, specifically, the cells you want, like heart, lung, liver, kidney, or whatever. Cells from a universal donor (or the original) are then cultured on the matrix to create an artificial organ. This artificial organ is then used to replace the damaged or diseased one.
More advanced than this is the use of tissue engineering to replace limbs. For the replacement, bone is not used, but a very durable, very light biologically inert ceramic composite. The scaffolding for the tissue is then put in place and the cells cultured there. This is more complex and requires advances in material sciences to help work.
Tech Levels: Biotech 4 for organ replacement; Biotech 5, Nanotech 4 for limb replacement and the creation of artificial organs with new properties.
Descriptors: Procedure for the technique, Internal for the results.