Engineering an in vitro 3D tissue construct to study peripheral nerve regeneration

Peripheral nerve injury (PNI) remains highly pervasive in modern society with over twenty million recorded cases in the United States alone. These injuries often result from traumatic injury, such as those presenting from car crashes, falls, or electric shock. The gold standard for PNI is an autologous nerve transplantation, which is limited by the generation of an additional surgical site, donor-site morbidity, and neuroma formation at the site of harvest. Our long-term goal is to develop tissue systems that will allow for the study of axonal growth and regeneration to ultimately develop clinically relevant strategies to stimulate targeted repair of longer peripheral nerve injuries. The overall objective of this proposal is to construct 3D systems to study axonal growth and regeneration. We hypothesize that finely controlled spatial and biochemical cues can significantly enhance axonal growth and regrowth in a 3D model to screen potential drug candidates for peripheral nerve regeneration. To systematically test this hypothesis, the following specific aims are proposed: Under the first aim, embryonic dorsal root ganglia (DRG) explants will be seeded in 3D hollow channels coated with specific ECM constituents located in the native axonal niche with or without Schwann cells (SCs) to evaluate their ability to support enhanced axonal growth and SC migration in real-time. Under the second aim, DRG explants will be cultured in medium supplemented with various drug compounds to develop a pre-clinical drug discovery model, which we will evaluate with certain non-steroidal anti-inflammatory drugs (NSAIDs) that may improve axonal growth/regrowth and enhance calcium signaling. Under the third aim, we will determine the mechanism of action for targeted NSAIDs using appropriate gain-of-function and loss-of-function experiments, confirming that these effects are independent of NSAID- mediated regulation of COX-1/2. Each Aim will be developed with embryonic DRGs, and validated with adult DRGs to maximize translatability. The approach is innovative, in our opinion, because it represents a substantive departure from the status quo by correlating axonal outgrowth rate and direction with calcium imaging techniques to quantify neuronal activity. Further, we will develop a model system that can be used to screen drugs, as there are no drugs currently administered to specifically treat peripheral nerve repair. The approach is significant because there is a clear need for effective systems to predict drug performance prior to pre-clinical or clinical trials to streamline the drug development process. The proposed model system will be able to separate out the study of physical cues, such as ECM molecules and integrin signaling, with soluble cues. The outcomes of this proposal will be the development of an architecturally relevant 3D tissue model to study axonal growth and repair that can screen potential drugs prior to pre-clinical studies to increase success rates and reduce development time and cost. The findings resulting from the proposed studies will enable the development of future biomaterial- based treatments to provide a translational pathway for these treatments towards the clinic to improve patient quality of life. Project Number: 1R15NS142925-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Neurological Disorders and Stroke (NINDS) | Principal Investigator: Jonathan Grasman | Institution: NEW JERSEY INSTITUTE OF TECHNOLOGY, NEWARK, NJ | Award Amount: $553,292 | Activity Code: R15 | Study Section: Bioengineering and Tissue Engineering for Neuroscience Study Section[BTEN] View on NIH RePORTER: https://reporter.nih.gov/project-details/11291903