Chondroitin Sulfate Glycosaminoglycan Hydrogels Create Endogenous Niches for Neural Stem Cells

Bioconjug Chem. 2015 Dec 16;26(12):2336-49. doi: 10.1021/acs.bioconjchem.5b00397. Epub 2015 Oct 20.

Abstract

Neural stem cells (NSCs) possess great potential for neural tissue repair after traumatic injuries to the central nervous system (CNS). However, poor survival and self-renewal of NSCs after injury severely limits its therapeutic potential. Sulfated chondroitin sulfate glycosaminoglycans (CS-GAGs) linked to CS proteoglycans (CSPGs) in the brain extracellular matrix (ECM) have the ability to bind and potentiate trophic factor efficacy, and promote NSC self-renewal in vivo. In this study, we investigated the potential of CS-GAG hydrogels composed of monosulfated CS-4 (CS-A), CS-6 (CS-C), and disulfated CS-4,6 (CS-E) CS-GAGs as NSC carriers, and their ability to create endogenous niches by enriching specific trophic factors to support NSC self-renewal. We demonstrate that CS-GAG hydrogel scaffolds showed minimal swelling and degradation over a period of 15 days in vitro, absorbing only 6.5 ± 0.019% of their initial weight, and showing no significant loss of mass during this period. Trophic factors FGF-2, BDNF, and IL10 bound with high affinity to CS-GAGs, and were significantly (p < 0.05) enriched in CS-GAG hydrogels when compared to unsulfated hyaluronic acid (HA) hydrogels. Dissociated rat subventricular zone (SVZ) NSCs when encapsulated in CS-GAG hydrogels demonstrated ∼88.5 ± 6.1% cell viability in vitro. Finally, rat neurospheres in CS-GAG hydrogels conditioned with the mitogen FGF-2 demonstrated significantly (p < 0.05) higher self-renewal when compared to neurospheres cultured in unconditioned hydrogels. Taken together, these findings demonstrate the ability of CS-GAG based hydrogels to regulate NSC self-renewal, and facilitate growth factor enrichment locally.

MeSH terms

  • Animals
  • Brain-Derived Neurotrophic Factor / administration & dosage
  • Cell Proliferation
  • Cells, Cultured
  • Chondroitin Sulfates / chemistry*
  • Fibroblast Growth Factor 2 / administration & dosage
  • Hydrogels / chemistry*
  • Neural Stem Cells / cytology*
  • Rats
  • Tissue Scaffolds / chemistry*

Substances

  • Brain-Derived Neurotrophic Factor
  • Hydrogels
  • chondroitin sulfate glycosaminoglycan
  • Fibroblast Growth Factor 2
  • Chondroitin Sulfates