Published by the Students of Johns Hopkins since 1896
April 14, 2024

Undergraduate team named finalists of Collegiate Inventors Competition

By ALEXANDRA GORHAM | October 1, 2021



(From left to right) Bruce Enzmann, Anson Zhou, Michael Lan and Juan Diego Carrizo are members of the Innerva team.

A team of four Whiting School of Engineering students was named as a finalist in the 2021 Collegiate Inventors Competition for its device, the Innerva Conduit. The invention facilitates nerve regeneration and decreases pain in amputee patients.

The team is comprised of 2021 graduate Michael Lan, senior Materials Science major Bruce Enzmann, junior Biomedical Engineering major Anson Zhou and junior Materials Science major Juan Diego Carrizo. 

The team, which at conception included only Lan, Enzmann and Zhou, first met in the fall of 2019 through working in the Mao Research Group, headed by Hai-Quan Mao, associate director of the Institute for NanoBioTechnology and advisor to the Innvera team. Carrizo joined the research group and the team in the spring of 2021 in advance of Lan’s graduation.

Mao has a longstanding partnership with Dr. Sami Tuffaha, assistant professor of plastic and reconstructive surgery, who came to him in 2019 with a prevalent issue in peripheral nerve surgery and repair for amputee patients.

After nerves are severed, they regenerate, often in a chaotic fashion that creates neuromas, disorganized bundles of nerves that are incredibly painful. Zhou noted in an interview with The News-Letter that this issue is particularly problematic in Innerva Conduit’s target demographic

“It’s one of the biggest issues for amputee patients because they are experiencing some of the most traumatic types of peripheral nerve injuries,” Zhou said.

In the past, doctors have attempted to curb neuroma growth and decrease pain through a variety of different methods aimed at preventing regrowth of severed nerves, including burying the severed nerve in a muscle or capping the nerve ending. However, none of these procedures have been successful, and it has been found that the prevention of nerve regrowth could actually hinder an amputee patient’s ability to use modern prosthetics.

“For these higher-level robotic prosthetics, they actually need to detect signals from those truncated nerves, and that allows them to process those signals and allow for very intuitive natural movement, unlike some of the current prosthetics that are not very intuitive,” Zhou said.

Thus, the most effective current method is targeted muscle reinnervation (TMR), which aims to connect the severed nerve to a donor motor nerve to increase motor control and prevent the growth of neuromas. However, TMR is made much more difficult for surgeons and painful for amputee patients by the size mismatch between the two nerves.

After talking with Tuffaha about this issue, Mao introduced the problem to Lan, Enzmann and Zhou, who in time and with the addition of Carrizo developed the Innerva Conduit, a device that aims to facilitate nerve regeneration for application with TMR.

The device is a funnel conduit with a gel composite inside that allows for tapered growth of the nerves through its shape and inhibits nerve regeneration to prevent overgeneration through the gel composite. Zhou explained that this duality sets the team’s device apart from previous designs.

“The novelty of it is that it does almost opposite things to very tightly control the nerve regeneration,” Zhou said.


A schematic of the Innerva Conduit. The grey portion illustrates the wall of the conduit, with the blue coloring inside being the gel composite. The small and large pink cylinders represent the donor motor nerve and the severed nerve respectively. 

Carrizo also highlighted the Innerva Conduit’s uniquely flexible design that allows it to bend without losing its shape.

“There are conduits for this kind of nerve regeneration already in existence. However, these conduits both lack the general network inside and [are] mostly straight, so they don’t address that size mismatch,” Carrizo said.

The team tested its invention in an initial pilot study on a few dozen rats and is now conducting a larger ongoing trial, from which it hopes to publish results within the next year. The tests thus far have produced results that the team expected, indicating that the Innerva Conduit facilitates tapered growth of nerves and helps to facilitate the reintegration process.

Zhou reported that the Tuffaha lab also conducted a blinded study looking into the pain scales of the rats that used Innerva Conduit and found that those rats experienced little to no pain.

“It's actually comparable to rats that actually have no injury at all versus the current TMR procedure and then obviously the neuroma formation that have much higher pain scores,” Zhou said.

Looking toward the future, the group is exploring the regulatory pathway with hopes of the Innerva Conduit being approved by the Food and Drug Administration (FDA) in the future. The process includes meeting with consulting offices that help them map their path to FDA approval and conducting large-scale experiments required by the FDA. 

These experiments turned expensive, leading the team to apply for grant funding. The Collegiate Inventors Competition, whose representatives reached out to the team after hearing about its success in the Lemelson-Massachusetts Institute of Technology Program, offers an important opportunity for grant funding. In addition, the team is the 37th Hopkins-based group to become finalists in recent years of the competition.

“We’re part of a long line of Hopkins legacy in this competition, so we’re very excited to compete,” Zhou said.

The team has already submitted its final video presentation to the competition. Now, it looks forward to the final aspect of the competition on Oct. 13: the judges’ Q&A session.

“Moving forward we have to prepare for that. We need to try to think outside the box about what they could ask us and what we could clarify,” Carrizo said.

The College Inventors Competition will announce the final winning teams on Oct. 14, the day after the Q&A session. If Innerva is chosen as a winner, the team would win $15,000 to put toward future experiments.

In the interview, Zhou attributed much of the team’s success to the interdisciplinary nature of the group and the lab’s connection to the School of Medicine. Zhou explained how each of the team members brings different technical and soft skills to the group and specializes in a certain aspect of the project: Zhou focuses on the invention's commercialization, Carrizo concentrates on manufacturing and efficiency and both Lan and Enzmann are experienced with polymer chemistry.

Finally, Zhou and Carrizo highlighted the importance of their mentors, Mao and Tuffaha, to their work. The partnership between Mao and Tuffaha inspired much of the interdisciplinary work of Innerva and significantly strengthened the project.

“Mao is on the biomaterials, device-development side, and Sami Tuffaha is the clinical aspect, but their collaboration together is why translational research is done so well here at Hopkins,” Zhou said.

To learn more about the team and the Innerva Conduit, visit

Have a tip or story idea?
Let us know!

Comments powered by Disqus

Please note All comments are eligible for publication in The News-Letter.

Alumni Weekend 2024
Leisure Interactive Food Map
The News-Letter Print Locations
News-Letter Special Editions