Feasibility of magselectofection using CliniMACS. Percentage of the eGFP+ hUC-MSCs 48 hours after lentiviral magselectofection using LS columns or CliniMACS. hUC-MSCs were labeled with CD105 MicroBeads. LS columns were modified with the magnetic viral complexes formulated at nanoparticle/virus particle ratios of 20 fg Fe/VP (2.5 × 106 infectious particles per column) and 2.5 × 106 cells were applied to the column positioned in the MidiMACS magnet and incubated for 30 minutes at room temperature. For the CliniMACS separation, a prototype CliniMACS tubing set was used, allowing manual application of the same magnetic SOMag2/LV.eGFP complexes to the CliniMACS separation column by 3-way taps at each end of the column. A total of 107 cells were applied to a cell application bag, connected to this tubing set and separated using the standard CD34 selection process. After 2 cycles of selection, the procedure was paused and magnetic viral complexes composed of 107 infectious particles were added to the nonmagnetized column. After restarting the process and reloading the cells onto the modified column, the process was again interrupted for an incubation of 30 minutes at room temperature. The cells were then eluted from the LS columns manually and from the CliniMACS Tubing Sets by resuming the separation program.
