Nanoparticle-Mediated Gene Delivery via Balloon Angioplasty to Suppress Intimal Hyperplasia.

Abstract

BackgroundIn the U.S. alone, over 200,000 cardiovascular surgical procedures utilizing venous grafts fail annually, primarily due to restenosis caused by the physiological healing response known as intimal hyperplasia (IH). IH can be attributed to endothelial cell proliferation, narrowing the walls of the blood vessels through the role of key genes Pdx1 and VEGF-A. Pdx1 is a homeobox whose promoter can induce overexpression of VEGF-A, a gene which allows for the growth of the intima. While many genetic therapies work in vitro, targeted delivery in vivo often proves infeasible, rendering such therapies unusable. It was hypothesized that genes that could interfere with IH could be contained within nanoparticles and coated onto a surgical balloon in order to specifically and efficiently target the region of interest.MethodsshRNA-regulated knockdown of Pdx1 delivered to a rat carotid artery via nanoparticles could lower the expression of VEGF-A, thereby preventing endothelial growth, the development of a neo-intima, and ultimately occlusion. Scanning electron microscopy, transmission electron microscopy, fluorescence and confocal light microscopy, and real-time polymerase chain reaction were used in the analysis of samples to assess the extent of IH and levels of VEGF-A.ResultsSignificant results (P < 1.0 E-14) support the proposed hypothesis.Conclusions BackgroundIn the U.S. alone, over 200,000 cardiovascular surgical procedures utilizing venous grafts fail annually, primarily due to restenosis caused by the physiological healing response known as intimal hyperplasia (IH). IH can be attributed to endothelial cell proliferation, narrowing the walls of the blood vessels through the role of key genes Pdx1 and VEGF-A. Pdx1 is a homeobox whose promoter can induce overexpression of VEGF-A, a gene which allows for the growth of the intima. While many genetic therapies work in vitro, targeted delivery in vivo often proves infeasible, rendering such therapies unusable. It was hypothesized that genes that could interfere with IH could be contained within nanoparticles and coated onto a surgical balloon in order to specifically and efficiently target the region of interest. In the U.S. alone, over 200,000 cardiovascular surgical procedures utilizing venous grafts fail annually, primarily due to restenosis caused by the physiological healing response known as intimal hyperplasia (IH). IH can be attributed to endothelial cell proliferation, narrowing the walls of the blood vessels through the role of key genes Pdx1 and VEGF-A. Pdx1 is a homeobox whose promoter can induce overexpression of VEGF-A, a gene which allows for the growth of the intima. While many genetic therapies work in vitro, targeted delivery in vivo often proves infeasible, rendering such therapies unusable. It was hypothesized that genes that could interfere with IH could be contained within nanoparticles and coated onto a surgical balloon in order to specifically and efficiently target the region of interest. MethodsshRNA-regulated knockdown of Pdx1 delivered to a rat carotid artery via nanoparticles could lower the expression of VEGF-A, thereby preventing endothelial growth, the development of a neo-intima, and ultimately occlusion. Scanning electron microscopy, transmission electron microscopy, fluorescence and confocal light microscopy, and real-time polymerase chain reaction were used in the analysis of samples to assess the extent of IH and levels of VEGF-A. shRNA-regulated knockdown of Pdx1 delivered to a rat carotid artery via nanoparticles could lower the expression of VEGF-A, thereby preventing endothelial growth, the development of a neo-intima, and ultimately occlusion. Scanning electron microscopy, transmission electron microscopy, fluorescence and confocal light microscopy, and real-time polymerase chain reaction were used in the analysis of samples to assess the extent of IH and levels of VEGF-A. ResultsSignificant results (P < 1.0 E-14) support the proposed hypothesis. Significant results (P < 1.0 E-14) support the proposed hypothesis. Conclusions