Abstract 215: Targeting MT1-MMP via Polymeric Transfection is More Efficient to Inhibit the Cellular Processes of Intimal Hyperplasia
OBJECTIVE Polymeric transfection could be a valuable therapeutic tool as it may be less toxic and more predictable than traditional methods, which are often poorly translated to in vivo models. Matrix metalloproteinases (MMP), in particular MT1-MMP, play a role in intimal hyperplasia (IH) and their targeted inhibition should be examined in vivo for the prevention of IH. Here we established conditions for polymeric transfection in vascular cells and ex vivo tissue and assayed its efficiency in targeting MMP-modulated cellular processes of IH.
METHODS Vascular smooth muscle cells (HASMC) and rodent carotid artery segments were transfected with poly(β-amino ester) polymers (Stem) or equivalent DharmaFECT2 (Dharm) conjugated to GAPDH, negative control (NC) or MT1-MMP siRNA.
RESULTS Bioconjugate translocation was observed at 0.65μl polymer: 100pmol siRNA/ml (Fig 1A). Gene silencing was polymer concentration dependent in vitro, and the most efficient bioconjugate (1.95μl polymer: 100pmol siRNA/ml) resulted in significant silencing ex vivo (Fig 1B). Using these empirically derived conditions, polymeric silencing of MT1 resulted in increased gene knockdown (Fig 2A) and inhibition of HASMC migration (Fig 2B) and proliferation (Fig 2C) compared to Dharm.
CONCLUSIONS HASMC and arterial tissue were successfully transfected, and silencing of MT1 via polymeric transfection was more effective in gene knockdown and in inhibiting the cellular processes of IH development in vitro when compared with traditional techniques. Future studies using targeted polymeric gene therapy to inhibit MT1 in animal models may modify vascular response to injury and prevent vascular disease.
- © 2013 by American Heart Association, Inc.