Ultrasound-Targeting Transfection of Nano-Tissue-Type Plasminogen Activator Gene to Prevent In-Stent Thrombosis and Neointimal Hyperplasia After Stenting Intervention in Injured Rabbit Iliac Artery

摘要

Systemically administered recombinant t-PA thrombolytic therapy has become a standard clinical treatment for acute myocardial infarction. However, its significant complications remain. We in this study established an in-stent thrombosis model with intimal hyperplasia by de-endothelialization of rabbit iliac artery, followed by bare-mental stenting (BMS) implantation. We then constructed a highly expressive t-PA gene plasmid packed with albumin nanoparticles which were crosslinked to albumin ultrasound micro bubbles. The gene vector was then transferred into the implanted arteries under therapeutic ultrasound aid (1 MHz, 1.5 w/cm(2), 6 mins, intravenously) after stenting intervention. The expression of t-PA in the implanted arteries and tissues around them was detected by multiclonal antibodies to t-PA, using the indirect immunohistochemical method. Venous blood t-PA and D-dimer contents were tested before weeks 1, 2, 4 and 8 after the operation. The effects of the constructed t-PA gene plasmid on the in-stent thrombosis and vascular intimal hyperplasia were observed by routine pathological examination, morphometry for intimal thickness and area, and immuno-histochemical stains using the monoclonal antibody to PCNA for estimating the intimal SMC proliferation. The effective expression of the t-PA in the implanted arteries and their surrounding tissues in the ultrasonic field was obtained, followed by persistent rising of the blood t-PA and D-dimer in weeks 1, 2, 4 and 8 after the targeting transfection. The In-stent thrombosis and intimal hyperplasia were successfully restrained. The transfection of the albumin nano-t-PA gene into the implanted arteries under the ultrasound microbubbles was also successfully performed. The transfected nano t-PA gene could prevent the in-stent thrombosis and reduce intimal hyperplasia under the implanted stents.