now that 3d printing has made it easier togenerate custom-made prosthetics, bioengineers are looking ahead at manufacturing actualcellular material. such technology could be the basis for personalizedbiomedical devices; tissue-engineered skin, cartilage, and bone; or even working bladders. in a trends in biotechnology special issueon biofabrication, publishing august 17, researchers
3d printing for tissue engineering, review and consider the progress made in 3dbioprinting and what might be possible in the decades--or years--ahead. "organs-on-a-chip"--3d microengineered systemsthat mimic the structure and function of human tissue--are a strong contender in the raceto deliver inexpensive and efficient personalized
medicine. lung, gut, and pancreatic tissue have alreadybeen grown from human stem cells on the chips, which allow researchers to study physiologicaldifferences in these cells between patients as well as screen for drugs. manufacturing challenges exist to quicklyexpand the use of the technology, but 3d printing could reduce the labor and costs necessaryto build, seed, and meet the demand for chips printed skin made from cells set down on acollagen gel showed the presence of intercellular connections and biologically normal cell markers10 days after cultivation. in another study, researchers have been ableto grow blood vessels in this sheet of cells.
skin bioprinting is closer to reality thanone would think, but researchers are only at the beginning of considering the designsnecessary to help patients, especially those with burns or chronic wounds. while bone, cartilage, skin, muscle, bloodvessels, and nerves have all been printed in the laboratory, constructing more complexdesigns that can be implated in patients is still in development. craniofascial reconstruction, which wouldbenefit people with cancer or who have experienced facial injuries, seems to be an obvious candidateto pursue because of the amount of work already done on these cell types.
in the short term, 3d printed scaffolds couldbe used to improve spot defects in the jaw or other areas of the face. 3d bioprinting is demonstrating that precisemodels can improve the way we evaluate new drugs, such as by generating "organoids" madeup of multiple cell types, as well as a tumor model with engineered blood vessels. while such approaches could make it possibleto quickly monitor drug interactions in real time in multiple organs, much more iteration(e.g., adding blood vessels, connecting organ models) will be needed to realize this vision. efforts to create 3d blood vessel networkswithin bioengineered tissues--which would
be necessary to ensure tissue survival afterimplantation and an accurate replication of
human anatomy--have focused on stacking 2dlayers of cells or bioprinting 3d networks, which allows for high levels of spatial control. one challenge is to create tissues with bloodvessel networks that could directly connect to a patient's arteries or veins.
