The Effects of UV Sterilization of a Poly(Caprolactone-Urethane) Biomaterial on Rodent Brain and Spinal Cord Neural Progenitor Cell Biocompatibility (P03.262)

OBJECTIVE: The purpose of this study was to determine the in vitro biocompatibility of UV sterilized poly(caprolactone-urethane) biomaterial with rodent neural progenitor cells obtained from the brain and spinal cord. BACKGROUND: Repair of the injured spinal cord will require a combination of therapeutic strategies, and growth factor filled biodegradable guidance channels that can encapsulate an area of spinal cord injury are one means of facilitating combination therapy. Translation to clinical use requires testing of the effect of sterilization methods on these biomaterials. DESIGN/METHODS: Adult female Sprague-Dawley rat subventricular zone brain tissue and the ependymal region spinal cord tissue were extracted. Neurospheres were seeded into 96-well plates and fed with plain media (controls) or media that was incubated with discs of UV sterilized poly(caprolactone-urethane) biomaterial. Spheres were differentiated at 7, 14 and 21 day time points and then fixed in PFA for confocal microscopy imaging. Bright field images were taken to measure sphere diameter. RESULTS: Control spheres demonstrated a traditional linear growth pattern with average brain sphere sizes of 148.50±28.33μm, 218.55±56.44μm, and 234.03±76.18μm, and average spine sphere sizes of 162.93±51.25μm, 257.32±87.97μm, and 331.44±83.59μm at 7, 14 and 21 days respectively. In the biomaterial condition however, the sphere growth was slowed with average brain sphere sizes of 148.34±25.24μm, 162.12±36.96μm (26% smaller, p CONCLUSIONS: Unlike previous experiments with gamma sterilized poly(caprolactone-urethane) biomaterial which demonstrated biocompatibility, UV sterilization resulted in limited neurosphere growth. The UV treatment may have damaged the chemical bonds of the biomaterial to produce a more rapid breakdown and creation of toxic by-products. Future testing of this biomaterial will hopefully assess sterilization methods that are biocompatible and facilitate spinal cord injury repair. Supported by: The American Academy of Neurology, National and International Research Alliance Program, The Ottawa Hospital and the Ottawa Hospital Research Institute. Disclosure: Dr. Pripotnev has nothing to disclose. Dr. Walker has nothing to disclose. Dr. Coyle has nothing to disclose. Dr. Filardo has nothing to disclose. Dr. Dargaville has nothing to disclose. Dr. Rasoul has nothing to disclose. Dr. Tsai has nothing to disclose.