Bone marrow stromal cells (BMSCs) have proven useful for the treatment of various human diseases and injuries.
However, their reparative capacity is limited by their poor migration and homing ability, which are primarily dependent
on the SDF-1/CXCR4 axis. Most subcultured BMSCs lack CXCR4 receptor expression on the cell surface and exhibit
impaired migratory capacity. To increase responsiveness to SDF-1 and promote cell migration and survival of cultured
BMSCs, we used a combination of ultrasound-targeted microbubble destruction (UTMD) and liposomes to increase
CXCR4 expression in vitro. We isolated and cultured rat BMSCs to their third passage and transduced them with recombinant
plasmid pDsRed-CXCR4 using microbubble-mediated ultrasound irradiation and liposomes. Compared to some viral
vectors, the method we employed here resulted in significantly better transfection efficiency, CXCR4 expression, and
technical reproducibility. The benefits of this approach are likely due to the combination of “sonoporation” caused by
shockwaves and microjet flow resulting from UTMD-generated cavitation. Following transfection, we performed a transwell
migration assay and found that the migration ability of CXCR4-modified BMSCs was 9-fold higher than controls.
The methods we describe here provide an effective, safe, non-viral means to achieve high levels of CXCR4 expression.
This is associated with enhanced migration of subcultured BMSCs and may be useful for clinical application as well.