Thursday, March 12, 2015

3D Printing: Creating Models and Organs

Every year the amount of organ transplants needed increases, but the amount of organs donated has no means of keeping up with this ever increasing number. One solution that has been proposed is bioprinting. Bioprinting is defined as the 3-D printing of biological tissues through layering. For now the goal is to be able to print a few strips at a time to repair organs such as the liver and kidneys. In the future when proper printing methods are devised, the implications of it’s usage knows no bounds.

Because of the way 3D printers work, they are able to make more complicated designs than what humans could ever make, thus future structural problems are not an issue. They have the ability to potentially recreate the vascular structures required for making organs. Vascularization is a critical component of thick tissues and organs because it is responsible for a large part of nutrient regulation. The ability to create heterogeneous vasculature is seen as one of the major points of this 3D printing. One of the major issues, however is getting the cells to live when there are more than a few layers. As of now, the method of printing is such that human cells are grown in a petri dish and then used as 3D ink for these printers. The cells on the bottom, however, do not tend to live that long outside of their natural environment.

There have been multiple methods proposed for how to print these vascular structures. By using a liquid support- based printing approach, the goal is to entirely submerged the cells in a cross-linking support solution. In an experiment done by Christensen, Xu, Chai, Zhang, Vascular-like structures with horizontal and vertical bifurcations were printed “only as well as mouse fibroblast-based alginate bioinks.” The post printing viability remained above 90% 24 hours after printing and incubation. This technology could be utilized in the future to make more complicated structures and maybe even complicated tissues such as organs.

Violet Pietrok's skull model

Right now 3D printing is be used for medical procedures. In order to make certain object materials need to be molded, cut and placed together but by using a 3D printer the item can be assembled without such trials and tribulations. In 2013 there was a case in which a synthetic windpipe was printed for a toddler's surgery. Windpipes have also been printed using human cells so that there was no rejection from the body. This procedure happens instead of tracheotomy (having a tube inserted via the neck; the patient is now not able to speak and he wounds is susceptible to infection). 3D printing is also used to make models for both dental and surgical needs. By having an exact 3D model of the patient, the accuracy or a procedure is improved and the duration is shorter.Models of skulls and heart have been used in order to try to solve problems caused by disease and defects. In the case of Violet Pietrok, 3D models were used in trying to aid her in reshaping her skull in order to fix her facial deformities. In the case of Esther Perez, a child bone with a heart defect which require re-routing of the blood supply, doctors were able to make a 3D model of her heart in order to avoid cutting into her and making a decision during the operation.

Bioprinting specifially may also be used to create biosensors for the inside of cells. A biosensors is ““A chemical sensing device in which a biologically derived recognition is coupled to a transducer, to allow the quantitative development of some complex biochemical parameter.” Examples of a biosensor is a nucleic acid, proteins such as enzymes, antibodies, lectins, and organelles. They are used for measuring analytes such as organic compounds and ions. By mixing 3D printing and these biosensors, a future of implantable therapeutics can be observed.

Though 3D printing is already being used in medicine, we have not reached a level of ability so that we can print organs as needed. 3D models have been used for surgical procedures, but those were created using MRi images and they are not for implantation. So far 3 D printers have been able to small strips of cells and vascularization. But we still have a long way to go. Large organs need these vascularizations in order to survive outside of the body, but so far only simple ones can be synthesized. Beyond that, we can’t print tissues for more than 2-3 layers because after that the bottom most layers suffocate and die off. Even though we are lacking the technology to utilize 3D printing to the greatest medical extent, we are making progress in great strides.


Scientific Articles:

Christensen, K., Xu, C., Chai, W., Zhang, Z., Fu, J. and Huang, Y. (2015), Freeform inkjet printing of cellular structures with bifurcations. Biotechnol. Bioeng.. doi: 10.1002/bit.25501

Dias, Andrew D., David M. Kingsley, and David T. Corr. “Recent Advances in Bioprinting and Applications for Biosensing.” Biosensors 4.2 (2014): 111–136. PMC. Web. 13 Mar. 2015.


News Articles:

Griggs, Brandon. "The next Frontier in 3-D Printing: Human Organs -" CNN. Cable News Network, 5 Apr. 2015. Web. 12 Mar. 2015.

Weintraub, Karen. "Off the 3-D Printer, Practice Parts for the Surgeon." The New York Times. The New York Times, 26 Jan. 2015. Web. 12 Mar. 2015.

Aderholt, Monica. "World’s First Biologically 3D Printed WindPipe / Trachea." 3DPrintcom. N.p., n.d. Web. 12 Mar. 2015.

Childrens Hospital Los Angeles. "3D printing makes heart surgery safer for children." ScienceDaily. ScienceDaily, 29 January 2015. <>.



Cohen, Katherine C. Dr. John Meara Cutting into a Three-dimensional Model of Violet Pietrok’s Skull. Digital image. Off the 3-D Printer, Practice Parts for the Surgeon. The New York Times, 26 Jan. 2015. Web. 12 Mar. 2015.


  1. How does 3D printing work such that what is printed is not rejected by the human body. Do they use cells from the person they are printing for or do they incorporate self-recognition into the printing process somehow (i.e. antigens)?

  2. I find it very interesting that scientists are trying to find a way to give organs to those who need them instead of looking for people to donate. Although it is sometimes to find an organ for people because it needs to be a match so the body doesn't reject it, but I agree with Emma. How does it work and function? Is it just sort of neutral so the body automatically accepts it? I think it's great that this is something is being done since finding organ donors is difficult, but I think that 3D printing may still be a work in progress because it is just very hard to understand how it works.

  3. I agree with the previous comments. It sounds like an interesting concept, but at this early stage of development, there are still many complications such as whether these cells produced would be rejected by each individual's body and how effective these organs would be. It would be a complicated process to make organs specific to each individual. I was wondering if you saw any overlap of the 3D printing with stem cell research? I feel like these two topics would go hand in hand with each other.

  4. Something I was unaware of was the ability to use 3D printing in surgery already. I would assume this would be to replace bones and teeth/bones. Do you know what kind of material they are able to print out of? Making them this way would maybe allow for materials and shapes that are less likely to break down, so people who need knee or hip replacements wouldn't have to get their replacements replaced at some point.

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  6. This article shows how innovation is constantly at the forefront of medicine. I think it's interesting to see how an organ can be synthesized in such a way, and am amazed at the possibilities that this will provide in the medical field and in surgery. However, I wonder what the implications of this are ethically and what impact will this have on how we perceive biology from a social standpoint. As we move, more and more, toward a technological world, the lines between "natural" and "biological," and "artificial" and "synthetic" seem to be blurred.

  7. This innovation, if refined and improved, could bring monumental changes to many industries, not just the field of medicine. Think about the major medical limitations facing astronauts on the ISS right now. Robotic surgery has enabled us to perform complex procedures already, and if 3D printing could also be applied then there would be no need for astronauts to return to earth for medical reasons. That would be extremely exciting, and I can't wait for the day that this is implemented.

  8. I did not realize that we are able to use 3-D printers for things like this! As time goes on, I see this becoming more and more useful, especially if it is further developed and more widely available. The issue of finding organ donors when an organ is needed can be quite a challenge so being able to use a 3-D printer to overcome the stress of waiting on a donor list is a big step. I'm glad that this technology has already been proven to work in some cases, like creating the windpipe for the toddler and the skull for the woman with facial deformities. This can lead to big changes in medicine!

  9. Interesting post! Crazy how research is evolving and leading to new discoveries and possibilities with the help of technology. Whether or not they are able to achieve the purpose that they are trying to achieve I believe any advancements made will be helpful in some way to the field and they will find numerous ways to use this new technology.