Just like plastics and metals, biologic material can be used in 3D printing. Researchers are creating 3D bioprinters and printing techniques to engineer new functioning tissues and organs. However, critical challenges remain ahead.

Researchers are attempting to grow functioning tissues and organ replacements in the laboratory. These strategies typically involve nurturing cells in a nutrient bath until they have matured into a functioning tissue or organ that can be implanted into the body.

The body can also be used as a "bioreactor" on its own. Researchers pursuing this strategy use cellular therapy and the body as a bioreactor to maturate new tissues or organs within the body itself.

Similar to 3D printing in some ways, these research strategies use an extracellular matrix as a scaffold upon which scientists can seed cells, thereby growing new tissues or organs based on a scaffold that guides the cell placement and growth. 

Some animals have similar biology to us so that they can be used to incubate and mature human cells, tissues, and organs. Their bodies can provide support to the new tissues at critical times before they are transplanted into a patient in need.