Sulphonic groups induce formation of filopodia in mesenchymal stem cells

Glycosaminoglycans (GAGs) are an integral part of the extracellular matrix and glycocalix, i.e. the closest cellular environment. They are abundant in –OH groups and their bioactivity is also associated with the presence of negatively charged –SO₃H functionalities. Therefore, we have investigated and discussed the influence of these functional units on mesenchymal stem cells (MSCs) behaviour using single component and mixed self-assembled monolayers of alkanethiols with –SO₃H and –OH end groups. In the absence of serum, MSCs attachment, spreading, cytoskeleton organisation and motility were significantly influenced by the surface chemistry. We found that the sulfonic groups induce star-like cell shape with very intense actin staining and a high density net of filopodia that enlarge from the base of lamellipodia structures. Moreover, this response is concentration dependent and is apparent only for very short culture time in the presence of serum.