A piezoelectric gelatin scaffold for schwann cell induced spinal cord repair

Author

• Scott Stratton, New Jersey Institute of TechnologyFollow

Document Type

Dissertation

Date of Award

5-31-2023

Degree Name

Doctor of Philosophy in Biomedical Engineering - (Ph.D.)

Department

Biomedical Engineering

First Advisor

Treena Livingston Arinzeh

Second Advisor

Vivek A. Kumar

Third Advisor

Martin Oudega

Fourth Advisor

Joshua R. Berlin

Fifth Advisor

Teresa Wood

Abstract

Spinal cord injury (SCI) results in axonal damage and consequently, functional loss for which there is no effective treatment at the present time. Axon growth across the injured site is needed to restore disruptive axonal circuitry, which is needed for recovery of lost function, but endogenous axon growth is poor. A Schwann cell (SC) transplant has shown promise in promoting axon growth in the injured spinal cord. Similarly, it has been shown that axons grow into biomaterial conduits especially when they are engineered to provide physical and biochemical growth-promoting cues. While both approaches are promising, their overall effect on axon growth across a spinal cord lesion remains limited. Here, the use of a combination of a functional biomaterial scaffold with SCs may significantly augment axon growth across spinal lesions and induce greater SC and axon migration into the scaffold. Electrical cues have been shown to improve the growth of axons across lesions as well as induce the migration of SCs. A major drawback is the electrical cues require the use of external electrodes when used in the in vivo environment. Piezoelectric scaffolds, which generate an electric charge in response to mechanical stimuli, may eliminate the need for such external electrodes by using the body's own natural forces to generate electrical activity. However, traditional piezoelectric biomaterials are either non-biodegradable or lacking adequate mechanical properties. The use of a piezoelectric, biodegradable fibrous gelatin scaffold, was examined for its potential use for SCI. Gelatin scaffolds are poled in order to enhance their piezoelectric properties. Studies are performed in vitro using axotomized dorsal root ganglion (DRGs) in combination with SCs. It is found that the piezoelectric fibrous gelatin scaffolds in static conditions increase SC number over time, axon growth and migration, and SC-induced myelination depending upon the direction of polarity of the scaffold. To examine the piezoelectric effect, a stretch device is used to provide cyclic deformation during culture. Findings demonstrate that axon growth is greater on piezoelectric scaffolds when subjected to cyclic deformation in comparison to cultures using the non-piezoelectric control. The results of these experiments demonstrate that piezoelectric scaffolds have the potential to enhance axon growth with or without SCs and may be a viable approach for spinal cord repair.

Recommended Citation

Stratton, Scott, "A piezoelectric gelatin scaffold for schwann cell induced spinal cord repair" (2023). Dissertations. 1930.
https://digitalcommons.njit.edu/dissertations/1930