Objective: To assess the biological effects of passage through clinically relevant needles on the viability and metabolic activity of culture-expanded, human adipose tissue-derived mesenchymal stromal/stem cells (AMSCs).
Design: Prospective observational pilot study.
Setting: Academic medical center.
Participants: Patient-derived clinical-grade culture expanded AMSCs.
Interventions: AMSCs were passed through syringes without a needle attached (control), with an 18-gauge (25.4-mm) needle attached and with a 30-gauge (19-mm) needle attached at a constant injection flow rate and constant cell concentrations. Each injection condition was completed in triplicate.
Main outcome measures: Cell number and viability, proliferative capacity, metabolic activity, and acute gene expression as measured by cell counts, mitochondrial activity, and quantitative real time reverse-transcription polymerase chain reaction on day 0 (immediately), day 1, and day 4 after injection.
Results: AMSC viability was not significantly affected by injection, and cells proliferated normally regardless of study group. Postinjection, AMSCs robustly expressed both proliferation markers and extracellular matrix proteins. Stress-response mRNAs were markedly but transiently increased independently of needle size within the first day in culture postinjection.
Conclusions: Human, culture-expanded AMSCs maintain their viability, proliferative capacity, and metabolic function following passage through needles as small as 30-gauge at constant flow rates of 4 mL/min, despite an early, nonspecific stress/cytoprotective response. These initial findings suggest that culture-expanded AMSCs should tolerate the injection process during most cell-based therapeutic interventions.
Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.