Ultrasound-assisted magnetic nanoparticle-based gene delivery

Abstract

Targeted gene delivery is important in biomedical research and applications. In this paper, we synergistically combine non-viral chemical materials, magnetic nanoparticles (MNPs), and a physical technique, low-intensity pulsed ultrasound (LIPUS), to achieve efficient and targeted gene delivery. The MNPs are iron oxide super-paramagnetic nanoparticles, coated with polyethyleneimine (PEI), which makes a high positive surface charge and is favorable for the binding of genetic materials. Due to the paramagnetic properties of the MNPs, the application of an external magnetic field increases transfection efficiency while LIPUS stimulation enhances cell viability and permeability. We found that stimulation at the intensity of 30 mW/cm 2 for 10 minutes yields optimal results with a minimal adverse effect on the cells. By combining the effect of the external magnetic field and LIPUS, the genetic material (GFP or Cherry Red plasmid) can enter the cells. The flow cytometry results showed that by using just a magnetic field to direct the genetic material, the transfection efficiency on HEK 293 cells that were treated by our MNPs was 56.1%. Coupled with LIPUS stimulation, it increased to 61.5% or 19% higher than the positive control (Lipofectamine 2000). Besides, compared with the positive control, our method showed less toxicity. Cell viability after transfection was 63.61%, which is 19% higher than the standard transfection technique. In conclusion, we designed a new gene-delivery method that is affordable, targeted, shows lowtoxicity, yet high transfection efficiency, compared to other conventional approaches.

Effects of insonification on repairing the renal injury of diabetic nephropathy rats

“…The main parameters of ultrasonic research include I sata , which is the parameter used for alleviating acute kidney injury at a power density of 100 mW/cm 2 , 14 promoting skeletal muscle regeneration at a power density of 60 mW/cm 2 , 23 and targeted gene transfer at a power density of 30 mW/cm 2 . 24 In our previous studies, we have determined that the appropriate irradiation parameter for most cells is 30 mW/cm 2 . 25 26 Another crucial parameter in ultrasound research is PL, which has been extensively studied.…”

Clinical Applications of Low-Intensity Pulsed Ultrasound and Its Underlying Mechanisms in Dentistry

“…Low-intensity pulsed ultrasound (LIPUS) is a non-invasive acoustic radiation generally acknowledge to play a significant role in osteogenesis [1]. The intensity of LIPUS ranges from 30 mW/cm 2 to 100 mW/cm 2 . LIPUS shows mechanical vibrations at frequencies above the detection limit of human sound [2].…”

“…The intensity of LIPUS ranges from 30 mW/cm 2 to 100 mW/cm 2 . LIPUS shows mechanical vibrations at frequencies above the detection limit of human sound [2]. For avoiding tissue overheating, frequencies of 1~3 MHz and intensity of 30~90 mW/cm 2 for 5~30 min/day were often adopted in previous studies [3].…”