Compositional and structural analysis of glycosaminoglycans in cell-derived extracellular matrices

The extracellular matrix (ECM) is a highly dynamic and complex meshwork of proteins and glycosaminoglycans (GAGs) with a crucial role in tissue homeostasis and organization not only by defining tissue architecture and mechanical properties, but also by providing chemical cues that regulate major biological processes. GAGs are associated with important physiological functions, acting as modulators of signaling pathways regulating several cellular processes such as cell growth and differentiation. Recently, in vitro fabricated cell-derived ECM have emerged as promising materials for regenerative medicine due to their ability of better recapitulate the native ECM-like composition and structure, without the limitations of availability and pathogen transfer risks of tissue-derived ECM scaffolds. However, little is known about the molecular and more specifically, GAG composition of these cell-derived ECM. In this study, three different cell-derived ECM were produced in vitro and characterized in terms of their GAG content, composition and sulfation patterns using a highly sensitive liquid chromatography-tandem mass spectrometry technique. Distinct GAG compositions and disaccharide sulfation patterns were verified for the different cell-derived ECM. Additionally, the effect of decellularization method on the GAG and disaccharide relative composition was also assessed. In summary, the method presented here offers a novel approach to determine the GAG composition of cell-derived ECM, which we believe is critical for a better understanding of ECM role in directing cellular responses and has the potential for generating important knowledge to use in the development of novel ECM-like biomaterials for tissue engineering applications.