Enhanced bone morphogenic protein adenoviral gene delivery to bone marrow stromal cells using magnetic nanoparticle

OBJECTIVES: This study investigated the question of whether adenoviral magnetofection can be a suitable method for increasing the efficacy of gene delivery into bone marrow stromal cell (BMSC) and for generation of a high level of bone morphogenic protein (BMP) secretion at a minimized viral titer. MATERIALS AND METHODS: Primary BMSCs were isolated from C57BL6 mice and transduced with adenoviral vectors encoding β galactosidase or BMP2 and BMP7. The level of BMP secretion, activity of osteoblast differentiation, and cell viability of magnetofection were measured and compared with those of the control group. RESULTS: The expression level of β galactosidase showed that the cell transduction efficiency of AdLacZ increased according to the increased amount of magnetic nanoparticles. No change in cell viability was observed after magnetofection with 2 µL of magnetic nanoparticle. Secretion of BMP2 or BMP7 was accelerated after transduction of AdBMP2 and 7 with magnetofection. AdBMP2 adenoviral magnetofection resulted in up to 7.2-fold higher secretion of BMP2, compared with conventional AdBMP2-transduced BMSCs. Magnetofection also induced a dramatic increase in secretion of BMP7 by up to 10-fold compared to the control. Use of only 1 multiplicity of infection (moi) of magnetofection with adenoviral transduction of AdBMP2 or AdBMP7 resulted in significantly higher transgene expression compared to 20 moi of conventional adenoviral transduction. CONCLUSION: Magnetic particle-mediated gene transudation is a highly efficient method of gene delivery to BMSCs. Magnetofection can lower the amount of viral particles while improving the efficacy of gene delivery.