The morbidity of atherosclerosis in China's urban population significantly increased due to the changes of lifestyle and dietary structure and other factors, thus seriously threatening people's health. Vascular bypass surgery and percutaneous angioplasty are the main therapeutical means, but the postoperative intimal hyperplasia in vessels and anastomotic often result in a long-term unsatisfactory patency rates, so that patients can ultimately benefit from these treatments.
Gene therapy is regarded as one of the fundamental ways to solve the vascular disorders in the future while efficient and safe vector system is one of the key conditions for gene therapy. Nanocarriers have become the first choice for gene therapy because of their higher transfection rate, safety and low toxicity and non-immunogenicity. Polylactic glycolic acid (PLGA), as one of the biodegradable nano-materials, has been approved by U.S. Food and Drug Administration (FDA) and ...view middle of the document...
Ang II type 1 receptor-related protein (Angiotensin II Type I Receptor-Associated Protein, ATRAP), which was first isolated and cloned by Dzau, VJ in laboratory at Harvard University in recent years, has already been an important promising target gene of this kind.
The experiment was planned to be conducted in model rats of vascular injury and rat VSMC in vitro, while the efficiency and feasibility of gene transfection via nano-vector-mediated gene plasmid and ATRAP carrying nanoparticles were evaluated. This study will also demonstrate the function and the cellular and molecular mechanisms of nanoparticle-mediated ATRAP in the VSMC apoptosis and the inhibition of intimal hyperplasia.
Materials and Methods
In this study, a copolymer of polylactic acid and polyglycolic acid (PLGA) and a polyvinyl alcohol (PVA) were used to entrap and carry the ATRAP gene plasmid and to prepare the nano-particle mixture, and then the gene plasmid is transfected into the rat VSMC in vitro and the model rats of neck vascular injury via the nanoparticle-mediated gene transfection.
Methods: 1, construction of the nanoparticles-ATRAP gene transfection system: PLGA and PVA was used to entrap ATRAP gene plasmid, and the granularity and the transfection efficiency in vivo and in vitro detected and further improved. 2, in vitro study: The cytotoxic, the inhibition of VSMC proliferation and the promotion to apoptosis were observed by using VSMC transfected with nanoparticle-mediated ATRAP. 3, in vivo study: The inhibition of VSMC proliferation and the promotion to apoptosis of ATRAP were demonstrated in vivo by locally transfected nanoparticle-mediated ATRAP into rat carotid injured by a balloon catheter.
1. PLGA-mediated ATRAP showed good stability and no significant cytotoxicity, with a release time of about 10-14 days.
2. The mRNA and the expressed protein products of nanoparticle -mediated ATRAP were observed in endangium and tunica media vasorum of model rats.
1. The experiment proved that ATRAP significantly inhibited AT1R-mediated VSMC proliferation and vascular inflammation.
2. ATRAP mediated by pcDNA3 vector can inhibit the proliferation of VSMC and the intimal hyperplasia.