Sustained delivery of proangiogenic microRNA-132 by nanoparticle transfection improves endothelial cell transplantation

FASEB J. 2014 Feb;28(2):908-22. doi: 10.1096/fj.13-238527. Epub 2013 Nov 12.

Abstract

Transplantation of endothelial cells (ECs) for therapeutic vascularization or tissue engineering is a promising method for increasing tissue perfusion. Here, we report on a new approach for enhanced EC transplantation using targeted nanoparticle transfection to deliver proangiogenic microRNA-132 (miR-132) to cultured ECs before their transplantation, thereby sensitizing cells to the effects of endogenous growth factors. We synthesized biodegradable PLGA polymer nanoparticles (NPs) that were loaded with miR-132 and coated with cyclic RGD (cRGD) peptides that target integrin αvβ3 expressed on cultured human umbilical vein ECs (HUVECs), increasing NP uptake through clathrin-coated pits. Unlike previously reported NPs for miR delivery, these NPs slowly release RNA for several weeks. The endocytosed NPs remain in clathrin-coated vesicles from which they mediate intracellular delivery of siRNA or miRNA. Transfection of HUVECs with miR-132 enhances growth factor-induced proliferation and migration in 2D culture, producing a 1.8- and 5-fold increase, respectively. However, while the effects of conventional transfection were short-lived, NP transfection produced protein knockdown and biological effects that were significantly longer in duration (≥ 6 d). Transfection of HUVECs with miR-132 NP resulted in a 2-fold increase in the number of microvessels per square millimeter compared to lipid after transplantation into immunodeficient mice and led to a higher number of mural cell-invested vessels than control transfection. These data suggest that sustained delivery of miR-132 encapsulated in a targeted biodegradable polymer NP is a safe and efficient strategy to improve EC transplantation and vascularization.

Keywords: controlled release; nanotechnology; neovascularization; tissue engineering.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Female
  • Flow Cytometry
  • Human Umbilical Vein Endothelial Cells / transplantation
  • Humans
  • Mice
  • Mice, SCID
  • MicroRNAs / administration & dosage*
  • MicroRNAs / genetics*
  • Microscopy, Confocal
  • Nanoparticles / administration & dosage*
  • Nanotechnology / methods
  • Neovascularization, Physiologic
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tissue Engineering
  • Transfection / methods

Substances

  • MicroRNAs