Requires the removal of tissue from somewhere in the patient. Trauma is caused at the site where the autograft is taken. Skin autografting requires the creation of scar tissue elsewhere on the body to repair visible defects. Although implants cause inflammation, implanted materials cannot be destroyed by an immune response. Thus there is no rejection of implants.
Implants can replace most or all of the function of natural tissue in most cases.
Implants may have long-term side effects, such as the resorption of bone that can occur around rigid orthopedic implants. Because the approach seeks to regenerate entire tissues from a few cultured cells, the problem of donor shortage present for transplantation is alleviated. Depending on the source of cells for tissue regeneration, in vitro synthetic tissues may face the same rejection issues as transplanted tissues. The long-term stability of tissues generated in this manner is still unknown, as tissue engineering techniques have only progressed to clinical testing stages in the last ten years. In vitro approaches for complex tissue types like muscle, liver, or nerve are still experimental.