Neural repair by NT3-chitosan via enhancement of endogenous neurogenesis after adult focal aspiration brain injury

Biomaterials. 2017 Sep:140:88-102. doi: 10.1016/j.biomaterials.2017.04.014. Epub 2017 Apr 26.

Abstract

The latent regenerative potential of endogenous neural stem/progenitor cells (NSCs) in the adult mammalian brain has been postulated as a likely source for neural repair. However, the inflammatory and inhibitory microenvironment after traumatic brain injury (TBI) prohibits NSCs from generating new functional neurons to restore brain function. Here we report a biodegradable material, chitosan, which, when loaded with neurotrophin-3 (NT3) and injected into the lesion site after TBI, effectively engaged endogenous NSCs to proliferate and migrate to the injury area. NSCs differentiate and mature into functional neurons, forming nascent neural networks that further integrate into existing neural circuits to restore brain function. Three main actions of NT3-chitosan, i.e., pro-neurogenesis, anti-inflammation, and pro-revascularization, elicit significant regeneration after TBI. Our study suggests that through creating an optimal microenvironment, endogenous NSCs are capable of executing neural repair, thus widening the therapeutic strategies to treat TBI and perhaps stroke or other neurological conditions.

Keywords: Aspiration brain injury; Chitosan; Endogenous neurogenesis; Functional recovery; Microenvironment; NT3.

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / pathology
  • Brain / physiopathology
  • Brain Injuries / drug therapy*
  • Brain Injuries / pathology
  • Brain Injuries / physiopathology
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Chitosan / chemistry*
  • Drug Carriers / chemistry*
  • Female
  • Injections
  • Neural Stem Cells / cytology
  • Neural Stem Cells / drug effects
  • Neural Stem Cells / pathology
  • Neurogenesis / drug effects*
  • Neurotrophin 3 / administration & dosage
  • Neurotrophin 3 / therapeutic use*
  • Rats, Wistar
  • Recovery of Function / drug effects

Substances

  • Drug Carriers
  • Neurotrophin 3
  • Chitosan