Wharton’s Jelly-derived mesenchymal stromal cells retain their immunophenotype and immunomodulating characteristics after transfection with polyethylenimine

Abstract

Background: Wharton's Jelly-derived mesenchymal stromal cells (WJ-MSCs) present several advantages over other sources of multipotent stem cells, not only because they are obtained from 2 neonatal umbilical cord, which is considered a biological waste, but also display higher proliferation rate and low senescence at later passages compared to stromal cells obtained from other sources.In the field of tissue engineering, WJ-MSCs have a wide therapeutic potential, due to their multipotential capacity, which can be reinforced if cells are genetically modified to direct their differentiation towards a specific lineage; unfortunately, as primary cells, WJ-MSC are difficult to transfect. Therefore, the objective of the present work was to standardize a protocol for the transfection of WJ-MSCs using a cationic polymer. Such protocol is important for future developments that contemplate the genetic modification of WJ-MSCs for therapeutic purposes. Methods:In this work, WJ-MSCs were genetically modified using polyethylenimine (PEI) and a lentiviral plasmid that encodes for green fluorescent protein (pGFP). To achieve WJ-MSCs transfection, complexes between PEI and pGFP, varying its composition (N/P ratio), were evaluated and characterized by size, zeta potential and cytotoxicity. At the N/P ratio condition where the highest transfection efficiencies were obtained, immunophenotype, immunomodulation properties and multipotential capacity of WJ-MSCs were evaluated.Results: Here, we present the standardization of the transfection conditions of the WJ-MSCs in a monolayer culture with PEI. The concentrations of plasmid and PEI that have the best transfection efficiencies were established Conclusions: Transfection with PEI doesn't affect immunophenotype, immunomodulatory properties and differentiation capacity of WJ-MSCs.