Bioprinting and Tissues

With the advent of the 3D printer, it was only a matter of time before researchers sought ways to 3D print biological parts like tissues and organs. If we could successfully 3D print organs, we could partially relieve the need for organ transplants and also the danger of organ transplants. The reason the waiting lists for transplants can get so long is that different people have different biomarkers within their bodies and it is imperative that the body doesn’t reject the organ. This can happen if the body thinks the organ is a foreign body, and it will use its immune response against the organ which can lead to all sorts of complications.

The first step in 3D printing an organ is having the right cells to do so. Sometimes the cells are grown outside of the body and then reproduce, creating a large quantity of lab-grown cells in a short time period. For special types of cells that may not grow outside of the body, scientists also use stem cells, which are kind of like a blueprint for any type of cell. Stem cells are found naturally in the body and are plentiful in the early stages of fetal development, becoming specific cells as the baby forms.

After the cells are grown, the next step is to create a type of mold for the tissue or organ called a scaffold. To create blood vessel and tendon scaffolds, the most common method is is called electrospinning. Electrospinning involves dissolving the biomaterials (the cells) into a solvent, loading it into a syringe, and then applying a high electrical charge to the solution as it slowly leaves the syringe. Once the scaffold has been created, the actual process of creating the tissue or organ can begin. When engineering replacement tissues, it is very important that the cells are arranged in a very specific order. This structure ensures that the tissue will have the proper function.

Confocal microscopy image of 3D-printed, 1-centimeter-thick vascularized tissue

Picture Source: wyss.harvard.edu