title: Timing of mesenchymal stem cell delivery impacts the fate and therapeutic potential in intervertebral disc repair.
abstract: Cell-based therapies offer a promising approach to treat intervertebral disc (IVD) degeneration. The impact of the injury microenvironment on treatment efficacy has not been established. This study used a rat disc stab injury model with administration of mesenchymal stromal cells (MSCs) at 3, 14, or 30 days post injury (DPI) to evaluate the impact of interventional timing on IVD biochemistry and biomechanics. We also evaluated cellular localization within the disc with near infrared imaging to track the time and spatial profile of cellular migration after in vivo delivery. Results showed that upon injection into a healthy disc, MSCs began to gradually migrate outwards over the course of 14 days, as indicated by decreased signal intensity from the disc space and increased signal within the adjacent vertebrae. Cells administered 14 or 30 DPI also tended to migrate out 14 days after injection but cells injected 3 DPI were retained at a significantly higher amount versus the other groups (p < 0.05). Correspondingly the 3 DPI group, but not 14 or 30 DPI groups, had a higher GAG content in the MSC injected discs (p = 0.06). Enrichment of MSCs and increased GAG content in 3 DPI group did not lead to increased compressive biomechanical properties. Findings suggest that cell therapies administered at an early stage of injury/disease progression may have greater chances of mitigating matrix loss, possibly through promotion of MSC activity by the inflammatory microenvironment associated with injury. Future studies will evaluate the mode and driving factors that regulate cellular migration out of the disc. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:32-40, 2017.
authors.affiliation: Biomechanics and Bioengineering Research Lab, Feinstein Institute for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030.
authors.forename: Robert
authors.initials: R
authors.lastname: Maidhof
authors.affiliation: Biomechanics and Bioengineering Research Lab, Feinstein Institute for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030.
authors.forename: Asfi
authors.initials: A
authors.lastname: Rafiuddin
authors.affiliation: Biomechanics and Bioengineering Research Lab, Feinstein Institute for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030.
authors.forename: Farzana
authors.initials: F
authors.lastname: Chowdhury
authors.affiliation: Biomechanics and Bioengineering Research Lab, Feinstein Institute for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030.
authors.forename: Timothy
authors.initials: T
authors.lastname: Jacobsen
authors.affiliation: Biomechanics and Bioengineering Research Lab, Feinstein Institute for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030.|Departments of Molecular Medicine, Neurosurgery, and Orthopedic Surgery, Hofstra Northwell School of Medicine, Hempstead, New York.
authors.forename: Nadeen O
authors.initials: NO
authors.lastname: Chahine
mesh_terms: D000818:Animals; D055959:Intervertebral Disc Degeneration / Q000628:therapy*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D017207:Rats, Sprague-Dawley; D013997:Time Factors
keywords: animal model; inflammation; intervertebral disc; mesenchymal stem cells; spine