Senior Design: 3-D Printed PEEK Spinal Fusion Cages

Mutually inspired by industry interests, Materials Science and Engineering students Sabrin Hilal and Ahmed Salah came together during Senior Design to find a solution to improving surface functionalization of 3D-printed PEEK spinal fusion cages.

Sabrin Hilal (left) and Ahmed Salah

“In their current state, when these cages are implemented, there’s issues where the sample has subsidence. It moves around and doesn’t really adhere to the bone. We wanted to modify the surface with UV light, and allow for calcium phosphate to grow on top,” explained Hilal.

Salah adds, “We wanted to improve its adhesion to bones so that there’s a lower chance of subsidence and failures -- so when it’s implanted, you know it’s fully fused to the spine, and there’s a lowered rate of having to remove and implant again.”

This project topic initially caught their eye due to their collective interest in biomaterials, as well as the ability to work with MSE Department Head and Professor Dr. Michele Marcolongo on a team. Hilal notes that motivation came from seeing that their research could apply beyond a Senior Design project.

Salah shared how prior academic and professional encounters helped him progress. “For instance, the hydrophobicity measurements that we did, I have actually done in my co-ops. I had the  idea to mirror some of that work onto our project. It was definitely a lot of Sabrin and I researching and figuring out what worked best for our project, and what would give us the results we needed.”

Naturally, COVID-19 had an impact on this project’s finalization. From the time you start Senior Design, you’re able to look forward to spring term knowing this is when things wrap up and final touches are made. When Hilal and Salah left the lab for spring break with experiments running, they were excited to come back, see their results and use STM to look at the surface and determine whether they achieved growth of the calcium phosphate on the surface. With campus closures due to the pandemic, they weren’t able to do this.

3D-printed PEEK spinal fusion cages

“COVID definitely threw a curveball at us, but I think the silver lining of the entire situation was being able to re-evaluate how to take that step further without conducting physical experiments, and how to do a more intensive literature review using the data we already obtained,” Salah explains. “Both Sabrin and I are working remote, so we’re just collaborating through whatever resources we have. I think it really teaches you how to make the best with the bare bones you’re given.”

While Hilal and Salah are upset they can’t give final results, they’re able to positively reflect on their biggest takeaways from Senior Design. “For me, it’s definitely getting the experience to work with Dr. Marcolongo, seeing what we can do with what we’ve learned, and how this can eventually make a difference in the world. But it’s also taking into account during COVID how to make the best of what we have as well,” Sabrin concludes.