ADDITIVE MANUFACTURING
the skin bioprinter and printed in layers on the wound area, an institute representative explained.
“Our studies show that the new skin blends in with the
patient’s existing skin and looks similar to the surrounding skin,” Jackson said.
“You can create thin tissues, but if you try to do it too thick, you can’t do it without getting the nutrients in and the waste out,” he said. “Then everything gets a lot more complicated.”
Ibrahim Tarik Ozbolat, who moved from the University of Iowa to Penn State University within the last year, is work- ing on the vascularization hurdle too, in addition to work on tissue models for the pancreas, brain, bone, cartilage, bone and skin together (for craniofacial defects), and brain tumors. He’s said previously that the biggest challenge is making capillaries, whose internal diameter is of hair-like thinness. “We can make capillaries within hydrogel,” Ozbolat said. “The major problem is still making capillaries and integrating
“In the scaffold-free approach, we confi ne the cells and let the cells deposit some proteins. Making capillaries in a scaffold-free approach is a tough problem right now.” In his lab’s work with 3D-printed pancreatic islets—the clusters of up to hundreds of cells in the pancreas that se- crete insulin and other hormones—the islets sprouted capil- laries into the supporting scaffold, Ozbolat explained. “When you put the islets together the capillaries anasto- mose,” or connect, he said.
Cell Development Examined In addition to vascularization, another hurdle to scale is
related to cell development and tissue formation, said Scott Collins, chief technology offi cer of TeVido BioDevices (Austin, TX), a bioprinting company focused on building custom grafts for breast cancer reconstruction. The fi rm’s fi rst project is to improve nipple reconstruction, in part because plastic surgery results on this part of the reconstructed breast tend to fade and fl atten after a couple of years. “Fundamentally, we don’t fully understand how cells work in the 3D space,” Collins said. “The bioprinters are going to help us assess that and understand how cells work together and how we can lead them down the pathway to the tissue we’re trying to form.”
This sample in a petri dish shows a bioprinted scaffold with bone cells growing into it.
them with larger blood vessels. Also, maintaining their shape and structure.”
Ozbolat explained that his team includes two approaches to getting capillaries to grow: with a scaffold and without. “With the scaffold, we seed the cells and the cells grow within the material,” he said, “while the scaffold degrades.
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AdvancedManufacturing.org | June 2016
Translation a Formidable Obstacle On a more basic, yet global, level, Collins said there’s work yet to be done on developing an un- derstanding between those work- ing from a biological perspective and those who design, engineer and make the bioprinters the researchers are using. “Make sure you understand the capabilities and abilities of the tool you’re using and applying it from a tissue biology perspective,” Collins said.
Conversely, he said, people working on the mechanics of the printer must understand how much it affects and inter- acts with biology. David Wallace, vice president of MicroFab Technolo- gies Inc. (Plano, TX), is one of those “people working on the mechanics of the printer.” His company worked with Wake
Photo courtesy Penn State University
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