Organ Printing Callie Thomas BME 281 Fall 2012

The Organ Waitlist According to Organdonor.gov, there are 115,476 people in the U.S. alone on the waiting list for organ transplants (as of 2011). This is only a fraction of a percent of the total U.S. population, but there are many more who need organ transplants and cannot join the waitlist due to medical expenses. On average, 18 people die daily on this waiting list before a transplant can be received. There is a high demand for inexpensive but efficient artificial organs in the medical field.

A 3D printer works like a standard inkjet printer, laying down layer after layer of material. Instead of ink it uses plastic polymers, and places the layers on top of each other to form a 3D shape. Holes or gaps in the design are created by printing layers of water- soluble material, which are washed away after the piece is fully printed. How 3D Printing Works

An organ printer works similarly, only instead of polymers it prints layers of cells. The cells naturally bond with each other, and even organize themselves spatially. A hydrogel, primarily made of sugar and water, is also printed along with the cells to help them hold their shape (similar to the water-soluble material used in industrial printing). After the cells “cure,” or mature (generally 24 hours to 3 days), the hydrogel can be peeled away. The organ is then fully mature, and is placed in a basic life support system and further conditioned. How 3D Printing Works

As of yet, scientists have not created a fully functional organ, but with a recent breakthrough they are much closer to this goal. Currently, they are working on developing kidneys, bladders, and hearts. In 2011, a miniature (about the size of a quarter) human heart was printed which began beating minutes after its completion, bringing this concept closer to reality. A printed kidney TED Talks expo, October 2009

One major benefit this has is that the cells used to print the organ are samples of the patient's own stem cells, virtually eliminating the possibility of rejection. The organ will not wear out or need occasional maintenance like a fully mechanical organ transplant. 3D printing eliminates the need for a scaffold (a basic structure) to grow the cells on, which most artificially grown organs require. Another benefit is that the organ can be printed from a 3D computer model of an actual organ, and be sized up or down on the computer before printing- the organ can be customized to better suit the patient. Benefits

It’s difficult to print vascularization in an organ, so effective blood flow in the organs has been a major roadblock. The lifespan of the organs themselves is very limited, ranging from a few minutes to days, thus longevity of the organ needs to be worked on before they can be transplanted into a patient. Some organs have advanced functions beyond movement, storage, and filtration (such as the liver’s ability to regenerate) which have not been replicated in this particular lab setting. Difficulties and Limitations

In 2011, a term of German engineers developed a technique which effectively prints blood vessels by layering cells around a cylinder of hydrogel. By carefully printing whole series of these tubes a basic vascular system is created, which the organ can be printed around. This increases both the lifespan and the functionality of the organ. A Breakthrough:Separate Vascularization

Developing more refined printers which can print smaller details, thus eliminating the need to make a separate vascular system for the organs. Using this technology to print bones which are strong enough for implantation (bone-like replicas have been in progress since the 1990’s out of artificial powders). Longer lifespans and better conditioning of the organs themselves, to be able to actually use these in the medical field. Reduction of costs to make this technology available to more people. Future Goals:

Estes, Adam C. "The Reality of 3-D Printed Body Parts." The Atlantic Wire. The Atlantic Monthly Group, 1 Dec Web. 16 Sept Mironov, V., T. Boland, T. Trusk, G. Forgacs, and RR Markwald. "Organ Printing: Computer-aided Jet-based 3D Tissue Engineering." Web of Science (n.d.): n. pag. Web of Knowledge. Thomson Reuters, Apr Web. 16 Sept Mironov, V., V. Kasyanov, C. Drake, and RR Markwald. "Organ Printing: Promises and Challenges." Web of Science (n.d.): n. pag. Web of Knowledge. Thomson Reuters, Jan Web. 16 Sept Simonds, David. "Printing Body Parts- Making a Bit of Me." The Economist. The Economist Newspaper Limited, 18 Feb Web. 16 Sept Visconti, RP, V. Kasyanov, C. Gentile, J. Zhang, RR Markwald, and V. Mironov. "Towards Organ Printing: Engineering an Intra-organ Branched Vascular Tree." Web of Science (n.d.): n. pag. Web of Knowledge. Thomson Reuters, Mar Web. 16 Sept Text References

(In order of appearance) Picture References Fox, Stuart. "First Commercial 3-D Bioprinter Fabricates Organs To Order." PopSci (n.d.): n. pag. Popular Science. Bonnier Corporation Co., 17 Dec Web. 16 Sept Moon, Mariella. "Blood Vessels Made by a 3D Printer Could Lead to Functional Artificial Organs." (n.d.): n. pag. Tecca. Web. 16 Sept "3D PRINTED KIDNEY – STILL FROM TED TALK WITH ANTHONY ATALA – MARCH 2012." (n.d.): n. pag. Alpha-ville. 7 June Web. 16 Sept Pearson, Catherine. "Printing A Kidney: A Glimpse At The Future." The Huffington Post- The Internet Newspaper (n.d.): n. pag. The Huffington Post. Huffington Post, 25 May Web. 16 Sept