Bioprinting research is state of the art at the University of Iowa — and a new university study shows it will continue to pave the way for tissue engineering.

The UI Mechanical and Industrial Department established a bioprinting lab in 2011, and since then, it has discovered extensive findings that may change the manner in which organ transplants and drug testing is conducted.

“[The department] has made significant progress since its inception,” said Ibrahim Ozbolat, a UI assistant professor of mechanical and industrial engineering. “At that time only cells were printed, but now we can print tissues and also print the tissues on animals directly.”

3D bioprinting is the process of generating spatially controlled cell patterns using 3D-printing technologies. This process involves a layer-by-layer approach to generate tissue-like 3D structures for use in the medical field of tissue engineering.

The bioprinting makes it possible to print human tissue and even entire organs.

Some of the printed materials — called biomaterials — are stronger than average bodily materials, including soft tissue and bone. These substances can act as future substitutes, or even improvements, for original body materials.

Ozbolat said the focus of the lab has been printing blood vessels, pancreatic tissue, bone tissue, and cartilage tissue.

“We believe we can make functional tissues and organs for transplantation or drug testing using bioprinting,” Ozbolat said. “And that is why we heavily focus on it.”

He said the lab is working on bioprinting bone tissue for cranial defects on rat models.

“We print tissue directly on the rat, as the euthanized rat is placed under the bioprinter,” Ozbolat said.

A recent development in the research is a study involving a system for bioprinting perfusable vasculature tissues — those that can supply an organ, tissue, or body with fluid by circulating it through blood vessels.

The concept of tissue engineering — which combines cells with biomaterials to create living, functional tissues to provide a solution to the lack of suitable organs for transplantation — has been popular for several decades.

A large roadblock for this science has been the need for nutrients to be delivered to living cells in order for them to survive. This process requires a vascular network — the body’s network of blood vessels, but current 3D bioprinting methods to create this system aren’t effective.

The UI designed a system for bioprinting vascular conduits that allow fluid to be transported to living cells.

“We now integrate vascular network printing with the rest of the tissue to create perfusable vascularized tissues,” Ozbolat said.

Yin Yu, a UI biomedical engineering graduate student, focuses on printing cells for organ fabrication in his research.

“We are working on bioprinting of functional vascularized tissue and organ,” Yu said. “This is a major challenge facing tissue engineering and regenerative medicine.”

He said directly bioprinting of vasculature tissues is the first step toward the department’s final goal, and bioprinting of the conduits will provide a vascular network that can be integrated into the tissue and organ printing.

Kerim Moncal, a research assistant for UI mechanical and industrial engineering, said the purpose behind bioprinting materials is to successfully produce tissues.

He started working at the lab 10 months ago, he said, and since then, his research focus has been on improving the mechanical system of bioprinting so that it can occur more efficiently.

“I find optimal paramaters for the printing,” Moncal said. “These parameters usually surround ideal temperature and pressure, so my job is to find the most effective combination.”

Moncal said he works on the design and fabrication side of 3D bioprinting rather than the testing.

Yu said the UI study is the first of its kind to demonstrate the ability of directly bioprinting vascular conduits at microscale at any desired length, which is significantly simpler than other studies.

“This process will provide blood, nutrient supply, as well as waste removal to the system,” he said. “These are key factors to grant functional tissue and organ survival.”