Ultrasound-targeted microbubble destruction enhances naked plasmid DNA transfection in rabbit Achilles tendons in vivo

Abstract

The study was to investigate the probability of increasing the transfection of the gene in tendons by ultrasound-targeted microbubble destruction (UTMD), and to search for the most suitable transfection conditions. A mixture of microbubbles and enhanced green fluorescent protein (EGFP) plasmids was injected into rabbit Achilles tendons by different administration routes and the tendons were ultrasound pulse by different ultrasonic conditions in order to determine the most appropriate conditions. Then, the rabbits were divided into four groups: (1) ultrasound + microbubbles + plasmid; (2) ultrasound+ plasmid; (3) microbubble + plasmid; (4) plasmid only. EGFP expression in the tendons and other tissues, and the damage to tendon and paratenon were all observed. The results showed that EGFP expression in the tendon was higher by ultrasound pulse with 2 W cm À2 of output intensity and a 20% duty cycle for 10 min. Local injection was determined to be the better administration route. Among the four groups, EGFP expression in Group 1 was higher than that in other groups. EGFP expression was highest on seventh day, then it gradually decrease over time, and lasted more than 56 days. EGFP expression was not found in other tissues. There was no obvious injury caused by UTMD. Under suitable conditions, it is feasible to use UTMD as a safe and effective gene transfection therapy for tendon injuries.

A transendocardial delivery and intracardiac ultrasound irradiation treatment catheter

“…The mechanical effect of ultrasound allows increases in biomembrane permeability and changes in membrane potential (Junqueira et al, 1979;Beeri et al, 2002;Li et al, 2003;Chappell et al, 2008;Yuan et al, 2011;Qiu et al, 2012). The non-thermal effect is related to cavitation, and such cavitation may lead to strong viscous stress.…”

“…(4) A total of 500 mg of plasmid DNA in 0.5 mL solution was injected to the five sites (each site received 100 mg of plasmid DNA) along the LV free wall, including four sites at the middle to lower part of the free left ventricular wall and one site at the tip of the heart. A US catheter was used to insonate each site in the EGFP-US group; insonation was conducted for 30 s, with a 10 s pause, at 4.3 MHz and 1 W/cm 2 , and the total insonation time was 60 s (Qiu et al, 2012). In the EGFP alone group, the gene was injected into the myocardium without insonation.…”

Use of ultrasound-targeted microbubble destruction to transfect IGF-1 cDNA to enhance the regeneration of rat wounded Achilles tendon in vivo

“…A number of nonsurgical treatments have been explored, including medication, physiotherapy and steroid hormone injection, to promote tendon healing, but none of these methods is really effective or has been widely applied clinically. 3 Tissue growth factors can regulate cell proliferation, migration of fibroblasts, differentiation and matrix synthesis and have the potential to directly influence cellular mitogenesis, thus having an important role in tendon repair. [3][4] Insulin-like growth factor-1 (IGF-1) induces tenocyte migration and division, matrix expression and collagen synthesis, thus having the potential to enhance wounded tendon regeneration.…”

“…3 Tissue growth factors can regulate cell proliferation, migration of fibroblasts, differentiation and matrix synthesis and have the potential to directly influence cellular mitogenesis, thus having an important role in tendon repair. [3][4] Insulin-like growth factor-1 (IGF-1) induces tenocyte migration and division, matrix expression and collagen synthesis, thus having the potential to enhance wounded tendon regeneration. 4 Many studies 5 have demonstrated that IGF-1 can promote tendon repair and enhance wounded tendon regeneration.…”

“…3 Generally, the vectors that are used for gene therapy can be divided into viral vectors and nonviral vectors, both with their own limitations. Viral vectors have high transfection efficiency, but the body may have immunologic rejections or the virus may be carcinogenic.…”