3D printing replacement tissues and organs is still in the early stages of development, but it is clear that custom printed implants will have to integrate multiple types of cells in different locations in order to perform like native tissues. Researchers at Rice University have just unveiled a new method of 3D printing solid plastic implants that incorporate different types of living cells. The printing and cell insertion is performed at almost the same time, which involves melting the thermoplastic and then incorporating cells and other biomaterials when the temperature moderates, resulting in 3D shapes containing cells. The Rice team managed to get their 3D printer to create grooves within the thermoplastic, which allows for the creation of multiple layers that simulate different tissue types. Chemicals that help the cells to proliferate can also be deposited right next to the cells during the printing process. A microCT image shows a 3D-printed scaffold with clear grooves meant for the deposition of live cells. The grooved lines hold ink deposited during the printing process. Scaffolds can be made in any shape, based on medical images, to fill the site of a wound. A microCT image shows a grooved thread that holds the low-viscosity bioink. They are part of a 3D-printed scaffold developed at Rice University to facilitate the growth of new tissues, such as bone and cartilage. The scaffolds degrade over time to leave layers of natural tissues in place. Most technology of this sort relies on hydrogel scaffolds, which are pretty squishy, but since the Rice team is using harder material their approach is more relevant to orthopedic surgery. Their thermoplastic is biodegradable and will leave the body after a certain amount of time. Source
