The effects of osmolarity on mesenchymal stem cells chondrogenesis
9th Biotechnology Congress
August 31-September 02, 2015 Orlando,Florida, USA

Sorouralsadat Ahmadian Davoudi

Tehran University, Iran

Posters-Accepted Abstracts: J Biotechnol Biomater


Articular cartilage is a unique tissue able to provide a low-friction, wear-resistant, load-bearing surface in joints for decades. However, this surface is commonly disrupted in an age-associated manner or through acute injury. However, cartilage has a very limited blood supply resulting in inadequate repair post injury. The most common treatments for cartilage repair ACI Autologous Chondrocyte Implant and MACI Matrix Assisted Autologous Chondrocyte transplantation take the advantage of autologous chondrocytes. However, such strategies suffer from donor site morbidity and inadequate cell supply. Alternatively, Mesenchymal Stem Cells (MSC) can be used to overcome such limitations. MSCs, can be induced to differentiate down the chondrogenic pathway under specific conditions. Osmolarity is a major biophysical regulator of chondrocyte function. Due to the presence of fixed, highly negatively-charged polysulphated proteoglycans, in comparison to other tissues there is an increase in cation (Na+, K+ and H+) concentration in articular cartilage, leading to cartilage having raised osmolality. The aim of this study was to investigate the effects of osmolarity on adipose derived MSC chondrogenesis. To fulfill that, MSCs were cultured under different hyper-osmotic conditions, using either NaCl as an ionic osmolyte, or sorbitol as an non ionic osmolyte and also an osmoprotectant or Poly Ethylene Glycol (PEG) as an organic osmolyte to raise the medium osmolarity. The effect of hyper-osmolarity on MSC growth and proliferation was evaluated by MTT assay. Changes in gene expression levels for cartilage specific markers Collagen II, Aggrecan, Versican, Sox9 and also for Matrix Metallo-Proteinase (MMP) were appraised by real time PCR. Also, chondrogenesis was assessed by measuring secreted glycosamin glycan in the medium or that kept in cell ECM. The results will be determined by the appropriate osmolarity and ideal sort of osmolyte for chondrogenesis.

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