Researchers at McMaster University have developed a new way to manufacture artificial lungs that could help premature babies in serious respiratory distress.
Building on established work in the field of microfluidic blood oxygenators, Anand Sojan, a PhD student in Ravi Selvaganapathy’s lab, developed and tested a new hybrid manufacturing technique that combines 3D printing with temporary sugar templates that dissolve after production to fabricate microfluidic devices that can help premature babies breathe.
“Babies who are born before gestational age often have underdeveloped lungs,” says Sojan. “Until their lungs fully develop, they need support through devices, like blood oxygenators, that help them breathe.”
But how do these devices work? It turns out it’s not so different from our lungs.
When you breathe, you inhale oxygen into your lungs. Tiny air sacs, called alveoli, transfer the newly inhaled oxygen into your bloodstream while carbon dioxide moves from your blood into the lungs and is released via exhalation.
If you are in respiratory distress, this gas exchange isn’t possible.
That’s where blood oxygenators come in. These devices do the same thing as your lungs, explains Sojan, but the process occurs outside the body. Acting as an artificial lung, oxygenators perfuse blood through tiny channels, exchange the oxygen and carbon dioxide outside the body, and return the blood to the patient.
While these devices are remarkably effective, current blood oxygenators are largely designed with adult patients in mind, which can prove deadly for premature babies.
“If you’re talking about a one-kilogram baby who is born prematurely and cannot breathe on its own,” says Sojan, “the total volume of blood used by these devices is more than the baby has in its entire body.”
This is why microfluidic oxygenators — the kind being designed in Selvaganapathy’s lab — are so important. They are a smaller device designed to provide the same gas exchange as our lungs while using a fraction of the blood that common oxygenators use.
The challenge, explains Sojan, has been developing manufacturing methods that allow these devices to be scalable and practical for real-world applications.
Traditional fabrication techniques rely on replica moulding, producing individual flat layers that must be assembled into larger systems using connectors and tubing. While effective for research in the lab, these production methods have high rejection rates and are difficult to scale into compact devices that can help premature babies.
Sojan’s technique is trying to fix that.
The new manufacturing method replaces conventional sacrificial plastic templates with 3D-printed sugar structures, colloquially called “candy lines.” After the candy lines are coated with gas-permeable silicone membranes, it dissolves in hot water, leaving behind an interconnected network of hollow microchannels.
Unlike polymer-based sacrificial templates, explains Sojan, using sugar eliminates the need for harsh chemical solvents like acetone that can complicate fabrication and potentially leach into the bloodstream.
“The simplicity of using sugar as a sacrificial material makes the process both accessible and compatible with biomedical manufacturing,” says Sojan. “It also produces fully open microchannels that can be perfused reliably.”
To demonstrate the technique, Sojan fabricated a prototype capable of meeting the nominal oxygenation requirements of a one-kilogram premature infant with respiratory distress syndrome, proving its ability to support their oxygen uptake at the relevant blood flow rate.
While the device remains a proof of concept, the prototype demonstrates that this manufacturing approach can produce functional oxygenators with significantly smaller blood volumes than conventional systems.
The long-term goal, says Sojan, is to create compact oxygenators that could provide respiratory support for premature babies while reducing many of the challenges associated with existing life-support technologies.
Moving forward, the team is going to explore scaling up the device, explains Sojan. “This one worked for a one-kilogram baby, but can we scale it up so that it works for a two-kilogram baby? How about a three-kilogram baby?”
They are also working with Christoph Fusch and Neils Rochow at Klinikum Nürnberg on animal trials, as well as fellow McMaster researcher Kyla Sask, an associate professor of Materials Science and Engineering, to develop a coating that prevents blood clots from forming.
While this work is ultimately still a prototype, the team has demonstrated that this manufacturing process brings them one step closer to making this device a reality.
“If we can simplify the fabrication process and make these devices easier to scale,” says Sojan, “it brings the field closer to technologies that can eventually be commercialized and made available for clinical care.”