A bioprinted heart, created when bio-ink is ejected, or “printed,” into the form of a 3D scaffold in the shape of a human tissue or organ.

The Division of Engineering in Medicine brings together a talented group of biomedical engineers. Immersed in the hospital environment, these bioengineers come from diverse scientific backgrounds and work across multiple disciplines, including biofabrication, materials science, nanotechnology, immunology, and biological sciences. This story concludes our series about how these investigators translate understandings of biology into novel diagnostic materials, medical devices and therapies.

Most drugs fail in clinical trials because their functions in animals don’t always translate to humans. If early drugs were tested on artificial organs — structurally and functionally like their human counterparts — the accuracy and effectiveness of testing drugs would be greatly improved. Yu Shrike Zhang, PhD, an associate bioengineer and assistant professor in the Division of Engineering, and his team are developing a way to screen drug candidates using three-dimensional structures that look and act the same as human organs and tissues.

“We can now use 3D bioprinting to create almost any living tissue structure, with varying degrees of functionality. These 3D models look and function very much like the human structures they represent. We have biofabricated artificial blood vessels, liver tissues, heart tissues and even human tumors,” said Zhang.

Unlike a conventional printer that deposits colored ink onto paper, the nozzle of a 3D bioprinter uses bio-ink, a mixture of cells (e.g., heart cells) and hydrogel, a gelatin-like biomaterial that nourishes the cells. This bio-ink is ejected, or “printed,” into the form of a 3D scaffold in the shape of a human tissue or organ.

The technology behind 3D bioprinting to create human tissues is known as organs-on-chips. These tiny devices mimic the physiology of human organs. “Organs-on-chips could be used to better predict the effects of drugs on the human body, and further in the future, to do personalized screenings for drug responses,” said Zhang.

The Zhang lab helped engineer an organs-on-chips system that models the human liver and heart. Such models could drastically reduce the time and money to bring a new drug to patients, which now takes an average of ten years and a billion dollars per drug.

Zhang recently used 3D bioprinting to build artificial tubular structures that can mimic blood vessels. Since many disorders damage tubular tissues in the body (e.g., atherosclerosis damages blood vessels), these complex structures may offer potentially viable platforms for drug screening and replacements for damaged tissues. Zhang’s goal is to create tubular structures with enough mechanical stability to sustain themselves with biologically relevant functionality.

In addition to using 3D bioprinted tissue models for drug screening, the Zhang lab is aiming to build fully functioning organs, which could help relieve the shortage of organs needed by hundreds of thousands of people waiting for transplants.

“It’s very unique and exciting to have a bioengineering division within a hospital environment. We have been collaborating with vascular surgeons and biologists at the Brigham to evaluate our 3D-bioprinted tubular tissues. Interacting with clinicians allows us to quickly translate our research into useful technologies that will ultimately help patients,” said Zhang.

If you enjoyed reading this story, check out the first and second stories in our Brigham Bioengineer series.