The regulation of expanded human nasal chondrocyte re-differentiation capacity by substrate composition and gas plasma surface modification

Biomaterials. 2006 Mar;27(7):1043-53. doi: 10.1016/j.biomaterials.2005.07.032. Epub 2005 Aug 24.

Abstract

Optimizing re-differentiation of clinically relevant cell sources on biomaterial substrates in serum containing (S+) and serum-free (SF) media is a key consideration in scaffold-based articular cartilage repair strategies. We investigated whether the adhesion and post-expansion re-differentiation of human chondrocytes could be regulated by controlled changes in substrate surface chemistry and composition in S+ and SF media following gas plasma (GP) treatment. Expanded human nasal chondrocytes were plated on gas plasma treated (GP+) or untreated (GP-) poly(ethylene glycol)-terephthalate-poly(butylene terephthalate) (PEGT/PBT) block co-polymer films with two compositions (low or high PEG content). Total cellularity, cell morphology and immunofluorescent staining of vitronectin (VN) and fibronectin (FN) integrin receptors were evaluated, while post-expansion chondrogenic phenotype was assessed by collagen types I and II mRNA expression. We observed a direct relationship between cellularity, cell morphology and re-differentiation potential. Substrates supporting high cell adhesion and a spread morphology (i.e. GP+ and low PEG content films), resulted in a significantly greater number of cells expressing alpha5beta1 FN to alpha(V)beta3 VN integrin receptors, concomitant with reduced collagen type II/ImRNA gene expression. Substrates supporting low cell adhesion and a spherical morphology (GP- and high PEG content films) promoted chondrocyte re-differentiation indicated by high collagen type II/I gene expression and a low percentage of alpha5beta1 FN integrin expressing cells. This study demonstrates that cell-substrate interactions via alpha5beta1 FN integrin mediated receptors negatively impacts expanded human nasal chondrocyte re-differentiation capacity. GP treatment promotes cell adhesion in S+ media but reverses the ability of low PEG content PEGT/PBT substrates to maintain chondrocyte phenotype. We suggest alternative cell immobilization techniques to GP are necessary for clinical application in articular cartilage repair.

MeSH terms

  • Adult
  • Biocompatible Materials / chemistry*
  • Cell Culture Techniques / methods
  • Cell Differentiation
  • Cell Proliferation
  • Cell Size
  • Cells, Cultured
  • Cells, Immobilized / physiology
  • Chondrocytes / cytology*
  • Chondrocytes / physiology*
  • Culture Media, Serum-Free
  • Gases / chemistry
  • Hot Temperature
  • Humans
  • Hyaline Cartilage / cytology*
  • Hyaline Cartilage / physiology*
  • Integrin alpha5beta1 / metabolism
  • Integrin alphaVbeta3 / metabolism
  • Nasal Septum / cytology
  • Nasal Septum / physiology
  • Polyesters / chemistry*
  • Polyethylene Glycols / chemistry*
  • Surface Properties
  • Tissue Engineering / methods*

Substances

  • Biocompatible Materials
  • Culture Media, Serum-Free
  • Gases
  • Integrin alpha5beta1
  • Integrin alphaVbeta3
  • PEGT-PBT copolymer
  • Polyesters
  • Polyethylene Glycols