Ps-91: The Effect of Hydrostatic Pressure on Growth Factor Induced Chondroinduction of Human Adipose-Derived Mesenchymal Stem Cells

Safshekan F *, Tafazzoli-Shadpour M , Shokrgozar MA , Haghighipour N , Mahdian R , Hemmati A ,


Objective: Tissue engineering using stem cells is a promising method for cartilage regeneration. In articular cartilage, chondrocytes sense mechanical signals such as hydrostatic pressure; and regulate the metabolism of proteoglycans and collagens to maintain homeostasis of extracellular matrix. Mimicking these conditions may improve chondroinduction of stem cells in vitro and can be used in cartilage tissue engineering applications. The aim of this work is to study the effect of intermittent hydrostatic pressure on growth factor induced-chondroinduction of human adipose-derived mesenchymal stem cells (hASCs). Materials and Methods: After isolation of hASCs from abdominal fat tissue, characterization by flow cytometry and assessing multilineage differentiation potential, pellets of passage 3 cells were used in experimental groups including: control group: pellets in routine culture medium, chemical group: pellets in chondrogenic differentiation medium containing TGF-β1, dexamethasone and ascorbate-2-phosphate for 10 days, and chemicalmechanical group: pellets in chondrogenic medium subjected to 3 MPa cyclic hydrostatic pressure (0.5 Hz) for 7 consecutive days form 4th day of pellet culture (4 hours/day) using a hydrostatic pressure device previously designed and fabricated in National Cell Bank of Iran. Real-time PCR method was used to examine the expression of aggrecan, as an important chondrogenic marker. Results: Cell surface protein expression examined by flow cytometry was highly characteristic of MSCs. Multilineage differentiation confirmed the multipotency of isolated hASCs. According to Real-time PCR results, application of cyclic hydrostatic pressure in chemicalmechanical group resulted in a significant increase in aggrecan expression (by 11 folds) compared to the chemical group. Conclusion: Higher expression of aggrecan, as an important chondrogenic gene, in the chemical-mechanical group, shows that mechanical signals are important factors in chondrogenesis and hydrostatic pressure can be used as an effective tool in hASCs chondrogenic differentiation and cartilage tissue engineering.