Effect of changing the frequency of biaxial loading on chondrocytes seeded in agarose gel / Yasir Mohammed Abdulqader Al-Saffar

• Main Author: Yasir Mohammed, Abdulqader Al-Saffar
• Format: Thesis
• Published: 2012
• Subjects: T Technology (General)
• Online Access: http://studentsrepo.um.edu.my/7606/4/yasir.pdf; http://studentsrepo.um.edu.my/7606/

In vivo, articular cartilage is under complex mechanical loadings. It is an accepted idea that mechanical stimulation of engineered articular cartilage may lead to better mechanical properties. In vitro biaxial stimulation has been found to be superior to uniaxial loading. Uniaxial loading has shown that change of frequency of stimulation give different effects on chondrocytes. However, the effect of change in frequency of biaxial stimulation is not documented yet. This study aims to test the effect of changes in the frequency of the biaxial loading of chondrocytes seeded in agarose gel. Direct compression amplitude of 10% and shear loading amplitude of 1% will be applied on agarose gel constructs seeded with chondrocytes. Three frequencies of 0.5Hz, 1Hz, and 1.5Hz are tested. Mechanical stimulation is applied for a period of 48hrs with 12hrs ON and 12hrs OFF. Before the start of mechanical stimulation a 24hr pre-culture rest will be allowed. DNA and GAG assays will be used to assess the response of chondrocytes and their production of extracellular matrix. Results obtained are in conformity with previous studies showing the advantage of mechanical stimulation over static culture with the frequency of 0.5 Hz having the highest GAG/DNA production in constructs, which shows that cells are still producing cartilage type extracellular matrix. DNA production in stimulated constructs was less than in static constructs. However the GAG production in all stimulated constructs was higher than in static constructs, which indicates that although cell number is lower in the stimulated constructs, yet their metabolic activity to produce cartilage extracellular matrix is much higher which further confirms the importance of mechanical stimulation in the regulation of cartilage extracellular matrix synthesis by chondrocytes. It is suggested that with a longer duration experiment there is a better chance for the frequencies to show any possible statistically significant differential effects they have on chondrocytes seeded in agarose gel under biaxial stimulation.