Nanomechanical properties of individual chondrocytes and their developing growth factor-stimulated pericellular matrix

Laurel Ng, Han Hwa Hung, Alexander Sprunt, Susan Chubinskaya, Christine Ortiz, Alan Grodzinsky

Research output: Contribution to journalArticlepeer-review

81 Scopus citations


The nanomechanical properties of individual cartilage cells (chondrocytes) and their aggrecan and collagen-rich pericellular matrix (PCM) were measured via atomic force microscope nanoindentation using probe tips of two length scales (nanosized and micron-sized). The properties of cells freshly isolated from cartilage tissue (devoid of PCM) were compared to cells that were cultured for selected times (up to 28 days) in 3-D alginate gels which enabled PCM assembly and accumulation. Cells were immobilized and kept viable in pyramidal wells microfabricated into an array on silicon chips. Hertzian contact mechanics and finite element analyses were employed to estimate apparent moduli from the force versus depth curves. The effects of culture conditions on the resulting PCM properties were studied by comparing 10% fetal bovine serum to medium containing a combination of insulin growth factor-1 (IGF-1)+osteogenic protein-1 (OP-1). While both systems showed increases in stiffness with time in culture between days 7 and 28, the IGF-1+OP-1 combination resulted in a higher stiffness for the cell-PCM composite by day 28 and a higher apparent modulus of the PCM which is compared to the FBS cultured cells. These studies give insight into the temporal evolution of the nanomechanical properties of the pericellar matrix relevant to the biomechanics and mechanobiology of tissue-engineered constructs for cartilage repair.

Original languageEnglish (US)
Pages (from-to)1011-1023
Number of pages13
JournalJournal of Biomechanics
Issue number5
StatePublished - 2007
Externally publishedYes


  • Cartilage
  • Chondrocytes
  • Growth factors
  • Nanoindentation
  • Nanomechanics
  • Pericellular matrix

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering
  • Orthopedics and Sports Medicine
  • Rehabilitation


Dive into the research topics of 'Nanomechanical properties of individual chondrocytes and their developing growth factor-stimulated pericellular matrix'. Together they form a unique fingerprint.

Cite this