California biotech company Frontier Bio has successfully bioprinted human lung tissue, setting a new milestone in tissue engineering. This progress could redefine how we treat respiratory diseases and approach organ transplants. This breakthrough could transform drug development for lung diseases like Chronic Obstructive Pulmonary Disease (COPD), a progressive condition that makes breathing difficult due to obstructed airflow, as well as pulmonary fibrosis and even COVID-19. By using human lung models, pharmaceutical companies might shorten development timelines, cut costs, and ultimately save lives.

By harnessing the power of stem cells and bioprinting technology, Frontier Bio is building a future where lab-grown tissues could eliminate the need for organ donors and human-like testing models replace outdated animal studies. With over 34 million people in the U.S. suffering from chronic lung diseases, the potential impact of this technology is enormous.

At the heart of this achievement is a lung tissue model that closely mimics the natural development of human lungs. This breakthrough combines a proprietary blend of biomaterials with cells found in the lung, including stem cells, which are printed into specific 3D structures.

What sets this innovation apart is the tissue’s ability to self-assemble into “complex microtissue architecture of the distal lung,” which includes the bronchioles and alveolar air sacs—the small, critical areas where oxygen and carbon dioxide exchange occurs. Additionally, the tissue forms functional beating cilia, tiny hair-like structures that sweep away mucus and debris, ensuring clean airways.

The bioprinted lung tissue even goes as far as producing mucus, which traps foreign particles, and surfactant, a substance vital for keeping the alveolar sacs open and preventing them from collapsing during breathing. These functional features, such as cilia and mucus production, make Frontier Bio’s lung models uniquely close to real lungs—so much so that the tissue even “breathes” like human lungs.

In an interview with Samand Pashneh-Tala, head of vascular tissue engineering at Frontier Bio, 3DPrint.com delved deeper into the potential impact of this innovation. “Our bioprinted lung tissue provides a more physiologically relevant platform for testing drugs and therapeutics for treating respiratory diseases, compared to traditional animal testing, which often doesn’t accurately mimic human physiology,” Pashneh-Tala explained. This, he noted, would address the high failure rates that occur when treatments are tested in animals but don’t translate effectively to human trials.

Sam Pashneh-Tala as new Head of Vascular Tissue Engineering at Frontier Bio. Image courtesy of Pashneh-Tala.

Moreover, this innovation doesn’t just stop at drug testing. The lung tissue model could one day provide an alternative to organ transplants, as Pashneh-Tala pointed out: “Bioprinted lung tissue could eventually be used to generate new tissue for implantation into individuals with diseased lungs, restoring healthy function. Currently, replacement lung tissue can only be delivered through transplants, but there is a huge shortage of donors and available tissue to meet needs.”

Pioneering geneticist George Church, an advisor to Frontier Bio, envisions even greater possibilities, stating that Frontier Bio isn’t just developing lab-grown human tissues—they’re paving the way for a future where organ donors are no longer needed, and animal testing is “a thing of the past.”

Frontier Bio’s process of bioprinting lung tissue is unique in its reliance on stem cells that differentiate into various lung cell types. Stem cells that normally reside in the lung produce the bioprinted lung tissue. These stem cells are then spatially positioned using bioprinting techniques and undergo a self-assembly process that mimics natural growth.

“We use chemical cues at specific times to direct the stem cells to differentiate into the required cell types to form the lung tissue,” Pashneh-Tala shared, explaining how their approach mirrors the natural development of lung tissue in the body. “Our approach uses 3D printing to position the cells spatially but then relies on natural self-assembly processes to generate smaller-scale features. The cells organize themselves into complex micro-tissue structures, such as alveolar air sacs in the lung. This is similar to how cells organize themselves during embryonic development and natural growth within the body.”

Frontier Bio engineer holding a bioreactor. Image courtesy of Frontier Bio.

One of the greatest challenges, according to Pashneh-Tala, was getting the various cell types found in the lung to self-assemble: “Our model includes multiple cell types that differentiate from stem cells. Developing methods to achieve this and having the cells arranged into the required structures took considerable effort.”

The bioprinted lung tissue models include bronchioles and alveolar air sacs, says the expert. These are the functional units of the lung and are the structures in which gaseous exchange with the blood takes place. Vascular cell types surround the alveolar air sacs, as seen in natural tissue. This breakthrough offers a more accurate testing model for respiratory diseases and the potential to eliminate the need for animal testing.

“Our bioprinted lung tissues could be adapted to produce new tissues or organs for implantation. This would replace the need for transplantation. The bioprinted lung tissue would need to be produced at a larger scale, but the functional unit, the alveolar air sacs, where gaseous exchange takes place, have been produced,” Pashneh-Tala told 3DPrint.com.

Frontier Bio’s approach stands out in the field, where some bioprinting techniques struggle to capture the fine details of human tissue, states the company. Their ability to harness natural self-assembly processes overcomes these limitations, leading to what it describes as functional tissue that behaves like actual lungs.

Looking ahead, Frontier Bio’s vision extends beyond lab-grown lung tissue. Their sights are set on partnering with pharmaceutical companies to accelerate drug development, particularly of new respiratory drugs, while advancing its bioprinting lung technology to a point where it can be used for human tissue implantation.

“We are continuously advancing the complexity of our models to one day generate tissue suitable for human implantation to restore lung function,” Pashneh-Tala concluded.

The company is actively seeking partnerships to bring this breakthrough into the drug development pipeline, with hopes that lab-grown lung tissue could soon become a reality in medical treatments.