Comparison of freshly cultured versus freshly thawed (cryopreserved) mesenchymal stem cells in preclinical in vivo models of inflammation: a protocol for a preclinical systematic review and meta-analysis

Background Mesenchymal stem cells (MSCs) are multipotent cells that demonstrate therapeutic potential for the treatment of acute and chronic inflammatory-mediated conditions. Especially for acute conditions, it is critical to have a readily available freshly thawed (cryopreserved) MSC product for rapid administration. Although controversial, some studies suggest that MSCs may lose their functionality with cryopreservation which in turn could render them non-efficacious. Objective In controlled preclinical in vivo models of inflammation, to determine if there are differences in surrogate measures of preclinical efficacy between freshly cultured and freshly thawed MSCs Methods/design A systematic search for pre-clinical in vivo inflammatory model studies will compare freshly cultured to freshly thawed MSCs from any source. The primary outcomes will include measures of in vivo preclinical efficacy; secondary outcomes will include measures of in vitro MSC potency. Electronic searches for MEDLINE and EMBASE will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. If applicable, study outcomes will be meta-analyzed using a random effects model. Risk of bias will be assessed by the SYRCLE “Risk of Bias” assessment tool for preclinical in vivo studies. Discussion The results of this systematic review will provide translational scientists, clinical trialists, health regulators, and the clinical and public community with the current pre-clinical evidence base related to the efficacy and potency of freshly cultured versus freshly thawed MSCs, help identify evidence gaps, and guide future related research. Systematic review registration Protocol is submitted to PROSPERO for registration (pending confirmation) and will be submitted to Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) for public posting.