Angiogenic microspheres promote neural regeneration and motor function recovery after spinal cord injury in rats

Sci Rep. 2016 Sep 19:6:33428. doi: 10.1038/srep33428.

Abstract

This study examined sustained co-delivery of vascular endothelial growth factor (VEGF), angiopoietin-1 and basic fibroblast growth factor (bFGF) encapsulated in angiogenic microspheres. These spheres were delivered to sites of spinal cord contusion injury in rats, and their ability to induce vessel formation, neural regeneration and improve hindlimb motor function was assessed. At 2-8 weeks after spinal cord injury, ELISA-determined levels of VEGF, angiopoietin-1, and bFGF were significantly higher in spinal cord tissues in rats that received angiogenic microspheres than in those that received empty microspheres. Sites of injury in animals that received angiogenic microspheres also contained greater numbers of isolectin B4-binding vessels and cells positive for nestin or β III-tubulin (P < 0.01), significantly more NF-positive and serotonergic fibers, and more MBP-positive mature oligodendrocytes. Animals receiving angiogenic microspheres also suffered significantly less loss of white matter volume. At 10 weeks after injury, open field tests showed that animals that received angiogenic microspheres scored significantly higher on the Basso-Beattie-Bresnahan scale than control animals (P < 0.01). Our results suggest that biodegradable, biocompatible PLGA microspheres can release angiogenic factors in a sustained fashion into sites of spinal cord injury and markedly stimulate angiogenesis and neurogenesis, accelerating recovery of neurologic function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anisotropy
  • Axons / metabolism
  • Axons / ultrastructure
  • Ephrin-A3 / metabolism
  • Female
  • Lactic Acid / chemistry
  • Magnetic Resonance Imaging
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Microspheres*
  • Motor Activity / physiology*
  • Neovascularization, Physiologic*
  • Nerve Regeneration / physiology*
  • Neural Stem Cells / metabolism
  • Organ Size
  • Polyglycolic Acid / chemistry
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Rats, Sprague-Dawley
  • Recovery of Function / physiology*
  • Spinal Cord / pathology
  • Spinal Cord / physiopathology
  • Spinal Cord Injuries / genetics
  • Spinal Cord Injuries / pathology
  • Spinal Cord Injuries / physiopathology*
  • Up-Regulation / genetics
  • White Matter / pathology
  • White Matter / physiopathology

Substances

  • Ephrin-A3
  • MIRN210 microRNA, rat
  • MicroRNAs
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid