Temporal exposure to chondrogenic factors modulates human mesenchymal stem cell chondrogenesis in hydrogels

Amanda N. Buxton, Chelsea S. Bahney, Jung Yoo, Brian Johnstone

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

Tissue engineering utilizes scaffolds containing chondrogenic cells to promote cartilage development at a clinically relevant scale, yet there remains a limited understanding of the optimal conditions for inducing differentiation and matrix production. We investigated how cell density and temporal exposure to chondrogenic factors impacted chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) diacrylate hydrogels. We found maximal proteoglycan and collagen production in constructs seeded between 10 and 25×106 cells/mL. Matrix deposition was significantly less per cell in constructs seeded at either higher or lower densities, indicating that paracrine communications may remain important despite loss of direct cell-cell contact. In vitro chondrogenesis of hMSCs was first accomplished using pellet cultures and a defined medium containing transforming growth factor (TGF)-β1 and dexamethasone. The differentiation of hMSCs in hydrogels also required initial exposure to TGF-β1, with no chondrogenic matrix produced in its absence. If TGF-β1 was initially included for at least 7 days, its removal impacted collagen production per cell but also lead to an increase in cell number, such that total collagen deposition was equivalent to controls when TGF-β1 was included for at least 3 weeks. Further, proteoglycan content per construct was higher at 6 weeks after removal of TGF-β1 at any time. In contrast to TGF-β1, dexamethasone was not required for chondrogenesis of hMSCs in hydrogels: there was no difference in matrix deposition between hydrogels cultured with or without dexamethasone. Further, without dexamethasone, SOX9 gene expression was higher during early chondrogenesis and there was a significant reduction in collagen I deposition, suggesting that a more hyaline cartilage phenotype is achieved without dexamethasone. Collagen content at 6 weeks was lower if dexamethasone was excluded after the first 7 days, but was equivalent to control if dexamethasone was included for 2 weeks or longer. Proteoglycan deposition was unaffected by dexamethasone exclusion. These results indicate that modulating exposure to TGF-β1 is beneficial for cell survival/proliferation and matrix production from hMSCs in hydrogels, and that not only is dexamethasone dispensable but also its exclusion may be advantageous for forming hyaline cartilage.

Original languageEnglish (US)
Pages (from-to)371-380
Number of pages10
JournalTissue Engineering - Part A
Volume17
Issue number3-4
DOIs
StatePublished - Feb 1 2011

Fingerprint

Chondrogenesis
Hydrogels
Human engineering
Stem cells
Mesenchymal Stromal Cells
Dexamethasone
Transforming Growth Factors
Collagen
Cartilage
Proteoglycans
Hyaline Cartilage
Cell Count
Paracrine Communication
Cell proliferation
Scaffolds (biology)
Intercellular Signaling Peptides and Proteins
Tissue engineering
Cell culture
Gene expression
Polyethylene glycols

ASJC Scopus subject areas

  • Bioengineering
  • Biochemistry
  • Biomedical Engineering
  • Biomaterials
  • Medicine(all)

Cite this

Temporal exposure to chondrogenic factors modulates human mesenchymal stem cell chondrogenesis in hydrogels. / Buxton, Amanda N.; Bahney, Chelsea S.; Yoo, Jung; Johnstone, Brian.

In: Tissue Engineering - Part A, Vol. 17, No. 3-4, 01.02.2011, p. 371-380.

Research output: Contribution to journalArticle

@article{903159f869fb416488ac5c9686279476,
title = "Temporal exposure to chondrogenic factors modulates human mesenchymal stem cell chondrogenesis in hydrogels",
abstract = "Tissue engineering utilizes scaffolds containing chondrogenic cells to promote cartilage development at a clinically relevant scale, yet there remains a limited understanding of the optimal conditions for inducing differentiation and matrix production. We investigated how cell density and temporal exposure to chondrogenic factors impacted chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) diacrylate hydrogels. We found maximal proteoglycan and collagen production in constructs seeded between 10 and 25×106 cells/mL. Matrix deposition was significantly less per cell in constructs seeded at either higher or lower densities, indicating that paracrine communications may remain important despite loss of direct cell-cell contact. In vitro chondrogenesis of hMSCs was first accomplished using pellet cultures and a defined medium containing transforming growth factor (TGF)-β1 and dexamethasone. The differentiation of hMSCs in hydrogels also required initial exposure to TGF-β1, with no chondrogenic matrix produced in its absence. If TGF-β1 was initially included for at least 7 days, its removal impacted collagen production per cell but also lead to an increase in cell number, such that total collagen deposition was equivalent to controls when TGF-β1 was included for at least 3 weeks. Further, proteoglycan content per construct was higher at 6 weeks after removal of TGF-β1 at any time. In contrast to TGF-β1, dexamethasone was not required for chondrogenesis of hMSCs in hydrogels: there was no difference in matrix deposition between hydrogels cultured with or without dexamethasone. Further, without dexamethasone, SOX9 gene expression was higher during early chondrogenesis and there was a significant reduction in collagen I deposition, suggesting that a more hyaline cartilage phenotype is achieved without dexamethasone. Collagen content at 6 weeks was lower if dexamethasone was excluded after the first 7 days, but was equivalent to control if dexamethasone was included for 2 weeks or longer. Proteoglycan deposition was unaffected by dexamethasone exclusion. These results indicate that modulating exposure to TGF-β1 is beneficial for cell survival/proliferation and matrix production from hMSCs in hydrogels, and that not only is dexamethasone dispensable but also its exclusion may be advantageous for forming hyaline cartilage.",
author = "Buxton, {Amanda N.} and Bahney, {Chelsea S.} and Jung Yoo and Brian Johnstone",
year = "2011",
month = "2",
day = "1",
doi = "10.1089/ten.tea.2009.0839",
language = "English (US)",
volume = "17",
pages = "371--380",
journal = "Tissue Engineering - Part A.",
issn = "1937-3341",
publisher = "Mary Ann Liebert Inc.",
number = "3-4",

}

TY - JOUR

T1 - Temporal exposure to chondrogenic factors modulates human mesenchymal stem cell chondrogenesis in hydrogels

AU - Buxton, Amanda N.

AU - Bahney, Chelsea S.

AU - Yoo, Jung

AU - Johnstone, Brian

PY - 2011/2/1

Y1 - 2011/2/1

N2 - Tissue engineering utilizes scaffolds containing chondrogenic cells to promote cartilage development at a clinically relevant scale, yet there remains a limited understanding of the optimal conditions for inducing differentiation and matrix production. We investigated how cell density and temporal exposure to chondrogenic factors impacted chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) diacrylate hydrogels. We found maximal proteoglycan and collagen production in constructs seeded between 10 and 25×106 cells/mL. Matrix deposition was significantly less per cell in constructs seeded at either higher or lower densities, indicating that paracrine communications may remain important despite loss of direct cell-cell contact. In vitro chondrogenesis of hMSCs was first accomplished using pellet cultures and a defined medium containing transforming growth factor (TGF)-β1 and dexamethasone. The differentiation of hMSCs in hydrogels also required initial exposure to TGF-β1, with no chondrogenic matrix produced in its absence. If TGF-β1 was initially included for at least 7 days, its removal impacted collagen production per cell but also lead to an increase in cell number, such that total collagen deposition was equivalent to controls when TGF-β1 was included for at least 3 weeks. Further, proteoglycan content per construct was higher at 6 weeks after removal of TGF-β1 at any time. In contrast to TGF-β1, dexamethasone was not required for chondrogenesis of hMSCs in hydrogels: there was no difference in matrix deposition between hydrogels cultured with or without dexamethasone. Further, without dexamethasone, SOX9 gene expression was higher during early chondrogenesis and there was a significant reduction in collagen I deposition, suggesting that a more hyaline cartilage phenotype is achieved without dexamethasone. Collagen content at 6 weeks was lower if dexamethasone was excluded after the first 7 days, but was equivalent to control if dexamethasone was included for 2 weeks or longer. Proteoglycan deposition was unaffected by dexamethasone exclusion. These results indicate that modulating exposure to TGF-β1 is beneficial for cell survival/proliferation and matrix production from hMSCs in hydrogels, and that not only is dexamethasone dispensable but also its exclusion may be advantageous for forming hyaline cartilage.

AB - Tissue engineering utilizes scaffolds containing chondrogenic cells to promote cartilage development at a clinically relevant scale, yet there remains a limited understanding of the optimal conditions for inducing differentiation and matrix production. We investigated how cell density and temporal exposure to chondrogenic factors impacted chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) diacrylate hydrogels. We found maximal proteoglycan and collagen production in constructs seeded between 10 and 25×106 cells/mL. Matrix deposition was significantly less per cell in constructs seeded at either higher or lower densities, indicating that paracrine communications may remain important despite loss of direct cell-cell contact. In vitro chondrogenesis of hMSCs was first accomplished using pellet cultures and a defined medium containing transforming growth factor (TGF)-β1 and dexamethasone. The differentiation of hMSCs in hydrogels also required initial exposure to TGF-β1, with no chondrogenic matrix produced in its absence. If TGF-β1 was initially included for at least 7 days, its removal impacted collagen production per cell but also lead to an increase in cell number, such that total collagen deposition was equivalent to controls when TGF-β1 was included for at least 3 weeks. Further, proteoglycan content per construct was higher at 6 weeks after removal of TGF-β1 at any time. In contrast to TGF-β1, dexamethasone was not required for chondrogenesis of hMSCs in hydrogels: there was no difference in matrix deposition between hydrogels cultured with or without dexamethasone. Further, without dexamethasone, SOX9 gene expression was higher during early chondrogenesis and there was a significant reduction in collagen I deposition, suggesting that a more hyaline cartilage phenotype is achieved without dexamethasone. Collagen content at 6 weeks was lower if dexamethasone was excluded after the first 7 days, but was equivalent to control if dexamethasone was included for 2 weeks or longer. Proteoglycan deposition was unaffected by dexamethasone exclusion. These results indicate that modulating exposure to TGF-β1 is beneficial for cell survival/proliferation and matrix production from hMSCs in hydrogels, and that not only is dexamethasone dispensable but also its exclusion may be advantageous for forming hyaline cartilage.

UR - http://www.scopus.com/inward/record.url?scp=79551513942&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79551513942&partnerID=8YFLogxK

U2 - 10.1089/ten.tea.2009.0839

DO - 10.1089/ten.tea.2009.0839

M3 - Article

VL - 17

SP - 371

EP - 380

JO - Tissue Engineering - Part A.

JF - Tissue Engineering - Part A.

SN - 1937-3341

IS - 3-4

ER -