Real-time monitoring of force response measured in mechanically stimulated tissue-engineered cartilage

Orahn Preiss-Bloom, Joseph Mizrahi, Jennifer Elisseeff, Dror Seliktar

Research output: Contribution to journalArticle

Abstract

Mechanical stimulation improves tissue-engineered cartilage development both in terms of biochemical composition and structural properties. However, the link between the compositional changes attributed to mechanical stimulation and the changing structural properties of the engineered cartilage is poorly understood. We hypothesize that transient events associated with construct stiffening can be documented and used to understand milestones in construct development. To do this, we designed and built a mechanical stimulation bioreactor that can continuously record the force response of the engineered construct in real time. This study documents the transient changes of the stiffness of tissue-engineered cartilage constructs over the first 14 days of their development under cyclic loading. Compressive strain stimulation (15%, 1 Hz) was applied to poly(ethylene glycol) (PEG) hydrogels seeded with primary articular chondrocytes. The average compressive modulus of strain-stimulated constructs was 12.7 ± 1.45 kPa after 2 weeks, significantly greater (P < 0.01) than the average compressive moduli of both unstimulated constructs (10.7 ± 0.94 kPa) and nonviable stimulated constructs (11.2 ± 0.91 kPa). The system was able to document that nearly all of the stiffness increase occurred over the last 2 days of the experiment, where live-cell constructs demonstrated a rapid 20% increase in force response. The system's ability to track significant increases in stiffness over time was also confirmed by Instron testing. These results present a novel view of the early mechanical development of tissue-engineering cartilage constructs and suggest that the real-time monitoring of force response may be used to noninvasively track the development of engineered tissue.

Original languageEnglish (US)
Pages (from-to)318-327
Number of pages10
JournalArtificial Organs
Volume33
Issue number4
DOIs
StatePublished - Apr 1 2009

    Fingerprint

Keywords

  • Biomechanics
  • Chondrocytes
  • Mechanical stimulation
  • Poly(ethylene glycol)
  • Tissue engineering

ASJC Scopus subject areas

  • Bioengineering
  • Medicine (miscellaneous)
  • Biomaterials
  • Biomedical Engineering

Cite this