Evaluation of 3D Printed Collagen Conduits Photocrosslinked with Ruthenium for Peripheral Nerve Injury Repair

INTRODUCTION DISCUSSION RESULTS • Neurotmesis is described clinically as the most severe form of peripheral neuropathy caused by physical trauma, with almost all cases of severe neurotmesis (gaps >15-20 mm) retaining only partial to no nerve function after surgical intervention. • Current treatments, primarily nerve autograft and synthetic nerve conduits, are limited in their ability to bridge neurotmesis gaps > 3 cm in length. • 3D bioprinting is a layer-by-layer technique to print a bioink, replete with cells and other biologics, into a 3D tissue-like arrangement. • The impact that photocrosslinkers have on the mechanical and cytocompatible properties of nerve conduits composed of extracellular biopolymers is important for maintaining structural integrity, and minimize adverse effects at the site of graft implantation • The toxicity profile of residual photocrosslinker molecules towards neural phenotypes and the biomechanical improvements it infuses into the conduit design must be investigated if this method of manufacturing is to be supported for clinical applications of neurotmesis repair. We investigated 3 Ruthenium cross-linking iterations combined with 240 LifeInk collagen ink on the biocompatibility and biomechanical properties of 3D printed collagen conduit applicable towards long gap nerve repair: Evaluation of 3D Printed Collagen Conduits photocrosslinked with Ruthenium for Peripheral Nerve Injury Repair Richard Steiner PhD1,2, Evan Phillips PhD1,2, Jack Buchen 1,2, Paul F. Pasquina, MD3, Luis M. Alvarez, PhD1,2, Shailly H. Jariwala, PhD1,2 1 Uniformed Services University of Health Sciences, Bethesda, MD 2 Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 3 Walter Reed National Military Medical Center, Bethesda, MD 20889, USA METHODS REFERENCES ACKNOWLEDGEMENTS & DISCLAIMER Fig 1. Schematic of collagen ink formulation and both crosslinking mechanisms. Ruthenium Ru(BPY)3/SPS mediated crosslinking occurs when a ruthenium bas
RITM0019392
Neurotmesis is described clinically as the most severe form of peripheral neuropathy caused by physical trauma, with almost all cases of severe neurotmesis (gaps >15-20 mm) retaining only partial to no nerve function after surgical intervention. Current treatments, primarily nerve autograft and synthetic nerve conduits, are limited in their ability to bridge neurotmesis gaps > 3 cm in length. 3D bioprinting is a layer-by-layer technique to print a bioink, replete with cells and other biologics, into a 3D tissue-like arrangement. The impact that photocrosslinkers have on the mechanical and cytocompatible properties of nerve conduits composed of extracellular biopolymers is important for maintaining structural integrity, and minimize adverse effects at the site of graft implantation The toxicity profile of residual photocrosslinker molecules towards neural phenotypes and the biomechanical improvements it infuses into the conduit design must be investigated if this method of manufacturing is to be supported for clinical applications of neurotmesis repair.