(176h) Secretome Indicators of End Tissue Quality during Human Mesenchymal Stem Cell Chondrogenesis

Human mesenchymal stem cells (hMSCs) have the potential to differentiate into cartilage, bone and tendon tissues, and they have been used for tissue engineering (TE) applications. Diseases like osteoarthritis can be treated if the therapeutic potential of hMSCs is exploited to regenerate patient-specific cartilage tissue. It has been established that the metabolism of the MSC directly affects the efficiency of chondrogenesis. However, studies have shown that the efficiency of differentiation has been low and variable depending on the donor. Our strategic goal is to develop non-invasive modalities to predict end tissue quality for TE. In this presentation, we discuss the use of amino acid uptake and tissue secretome to predict end-tissue quality. We carried out experiments using an hMSC aggregate model of chondrogenesis. Aggregates were cultured in differentiating medium at different culture conditions; initial glucose levels were varied from 1 to 4.5 g/l and media frequency was varied from 0.5 to 1 day^-1. We processed conditioned medium for biomolecular analysis. Proteomic data analysis shows that synthesis rates of chondrogenesis markers fibronectin, type 2 collagen, and MMP-2 strongly correlated with glucose metabolism (glycolysis). More importantly, these rate markers predicted the end tissue quality (collagen and glycosaminoglycan content) under differing culture conditions, suggesting that biomarkers in the medium can be used to predict chondrogenesis outcomes.