Miami, FL –A new chemical-engineering method that preserves normal human tissue properties gives surgeons and scientists the opportunity to test medical devices and drugs in a life-like environment.
David Almeida M.D., Ph.D., executive chairman of Erie Retina Research, and a team of scientists applied a special chemical formulation to human cadaveric tissue and found it preserved the eye’s elasticity and layered structures. The engineered tissue was named Near-real Surgical Specimen (NRSS).
“NRSS is truly revolutionary in its ability to mimic the exact tissue properties of living humans,” said Vinit Mahajan M.D., Ph.D., Stanford professor, vitreoretinal surgeon, and vice chair for ophthalmology research. “For the first time, we can test innovative surgical tools, techniques, and devices in humans rather than animal models. This means safer and more successful surgeries for patients. Equally important, it is a hands-on tool for training surgeons.”
The NRSS platform offers a unique solution to the challenges faced in traditional drug device studies. Unlike human cadaveric eyes preserved with formalin, which are stiff and vary significantly in their tissue properties, NRSS uses a proprietary preservative to chemically engineer human eyes to provide consistent, reliable, and real-life results. This means researchers testing techniques for drug delivery can observe how drugs spread immediately after injection in human tissues, leading to better insights into the effectiveness of different delivery devices.
In the ever-evolving field of ophthalmology, the quest for effective drug delivery methods to treat retinal diseases is paramount. Traditional approaches, such as intravitreal injections, have paved the way, but researchers are now turning their attention to a promising alternative: suprachoroidal drug delivery (SCDD).
This innovative method involves injecting medication into the space between the sclera and choroid, allowing for targeted treatment of conditions affecting the back of the eye. However, optimizing the injection devices and understanding how these injections work has been a challenge, until now. Working in the CaseX Miami lab, the team tested a series of SCDD devices using NRSS.
Almeida said, “One of the standout features of the NRSS platform is its ability to visualize the injection process in real-time. Using optical coherence tomography integrated into the surgical microscope, we can see how the drug interacts with the eye's tissues, providing valuable information that can help improve future drug delivery systems.”
Their published study, Near-Real Surgical Specimens (NRSS): A Novel Platform for Standardized Assessment of Suprachoroidal Drug Delivery, showed that the NRSS platform produced significantly less variability in drug coverage compared to cadaveric studies. This means that results from NRSS are more reliable, which is essential for developing effective treatments.
The team took on the challenge of helping to test and optimize various SCDDs. For example, using the Everads Suprachoroidal Injector, they found that the injected medication consistently spread in a predictable pattern, with the right technique and maneuvers. Initially, the drug moved quickly toward the back of the eye before gradually spreading to the surrounding area. This is a significant finding, as previous studies using different devices reported a different spread pattern.
Vinit Mahajan said, “It is impossible to replicate injections in traditional cadavers because they are rigid, and animal eyes aren’t a close enough match to the human eye. Now we have a good model to simulate working with a real living human eye to test surgical procedures and devices.”
Almeida added, “We recognized immediately that the NRSS was a game changer for R&D of new surgical devices and training eye surgeons in both old and new procedures.”
As suprachoroidal delivery continues to gain traction as a promising route for treating eye diseases, platforms like NRSS will play a vital role in ensuring that these advancements translate safely and effectively into clinical practice.
Mahajan said, “Working with the NRSS is so natural and real that after 60 seconds at the microscope, you forget it’s not a live patient. Being able to track the movement of medications within the eye is invaluable for researchers. Using the NRSS, we have also performed vitrectomies, subretinal injections, and cataract surgeries.”
The study of human cadaveric tissues has been a key part of understanding human surgical anatomy. Evolving methods and technologies have transformed anatomical dissections from the time of Leonardo da Vinci where he had to work quickly without preservatives to chronicle the inner workings of the human body. The NRSS has the potential to advance our knowledge of the human body and disease in new and exciting ways.
Almeida said, “The NRSS platform holds great potential for future research and development. It can be customized to simulate various eye conditions, making it an invaluable tool for testing new therapies and training medical professionals.”