Bioprinting (or biological printing) is older than many people think, but in 2D cell culturing, not 3D. The essence of new 3D printing is that it is an additive manufacturing process that builds layer upon layer until the final product is completed.
And yes, 3D bioprinting is similar, but instead of using a feedstock such as plastic or metal to make tools or iPhone covers, the bioprinter uses live human cells.
One of the future visions for 3D bioprinting is to make transplant organs and is being worked on today by companies like Organovo, Invetech, Envisiontec and Autodesk, and people like Professor Makoto Nakamura and a few others.
Ideally human cells would be collected from the person receiving the transplant and used in the bioprinter so that there will be no tissue rejection issues later.
The patient would undergo an MRI, CT scan or other type of medical scan that can be input into a computer in 3D. From there a computer aided design (CAD) program would be created of the organ that needs to be replaced. A doctor or technician would input data into the 3D file such as where to place each type of cell material and working around imperfections or damaged or diseased areas. When finished the doctor would hit the “Print” button.
Instead of the printer cartridges being filled with ink (or plastic or metal), they will be filled with human cells. The cells will be printed in micro thin layers using a binding agent such as collagen (hydrogel), sugar or biodegradable paper.
Cells Will Be Cells …
The cells then use their own innate ability to grow together as the rest of the organ is being printed. The cells don’t have to be placed in exactly the right spots as nature will take over and the cells will reorganize themselves for proper functioning. How this is done precisely is still a medical mystery (but it has been shown to work).
Human organs such as livers, kidneys, hearts, lungs and pancreas will one day in the future be created by 3D bioprinting. This means the end to long waiting lists for compatible organs and the end to people dying while on the waiting lists.
In the U. S. an average of 79 people per day receive organ transplants while 18 people a day die while on a waiting list. As of September 2013, 119,000 people are on the waiting list for organ transplants. So, you can see in the United States alone there is a high need for 3D bioprinters.
The Organovo NovoGen MMX bioprinter creates bioink spheroids each containing 10,000 – 30,000 cells. The spheroids are printed upon hydrogels, layer by layer. The spheroids will start to fuse together and then the cells will let Nature take its course and rearrange themselves.
For instance, each spheroid may start out with a mixture of smooth muscle, fibroblast and endothelial cells. Later, these cells will migrate into the correct configuration within the organ.
Besides printing transplant organs, experimental 3D bioprinters are already creating other tissues such as bones and teeth. Living bioprinted teeth and jawbone implants may one day reduce or eliminate the need for dentures.
Bioprinted hip bones, joints, skulls, vertebrae and other bones may one day become the norm. Jeremy Mao’s team of researchers at Columbia University have already created bioprinted hip scaffolds (for rabbits) with growth enhancers that have helped joints / bone to grow and the bunnies to walk and hop again.
In Situ (in position) 3D bioprinting is another area of much interest in medical science. And in fact the Military has a high interest in this particular type of bioprinting as well as others in order to help soldiers in the field who have been wounded.
An in situ bioprinter will be stabilized upon the patient and cells printed directly upon them. This will help people with burns or wounds to heal more quickly. The 3D in situ bioprinter will print skin cells along with collagen and coagulant directly upon the burn or wound.
The Ears Have It …
At Cornell University, Lawrence Bonassar, Ph.D., is using 3D bioprinting to create human cartilage, mostly for ears, but also presumably for noses, knees, elbows, joints, ribs and intervertebral discs as well. And this cartilage is not considered prosthetics since it is made of real human cells and tissue.
Researchers at Heriot-Watt University in Edinburgh, Scotland have used 3D bioprinting to create stem cells. The implications of this are far-reaching including replacing animal testing, organ transplants, viral testing and pharmaceutical testing.