Mimicking the endothelial glycocalyx through supramolecular presentation of hyaluronan on patterned surfaces
The glycocalyx is the immediate pericellular matrix that surrounds many cell types, including endothelial cells (ECs), and is typically composed of glycans (glycosaminoglycans, proteoglycans, glycoproteins). The endothelial glycocalyx is rich in hyaluronic acid (HA), which plays an important role in the maintenance of the vascular integrity, but fundamental questions about the precise molecular regulation mechanisms remain unanswered. Here we investigate the contribution of HA on the regulation of the endothelial function using model surfaces. The peptidesequence GAHWQFNALTVR, previously identified by phage display with strong binding affinity for HA and named as Pep-1, was thiolated at the N-terminal to form self-assembled monolayers (SAMs) on gold (Au) substrates, and microcontact printing (CP) was used to develop patterned surfaces for the controlled spatial presentation of HA. Acetylated Pep-1 and a scrambled sequence of Pep-1 were used as controls. SAMs and HA-coated surfaces were characterized by X-ray photoelectron spectroscopy (XPS), contact angle measurements, atomic force microscopy (AFM) and quartz crystal microbalance with dissipation (QCM-D) monitoring, which confirmed the binding and presence of thiolated peptides onto the Au surfaces and the deposition of HA. Fluorescence microscopy showed the localization of fluorescently labelled HA only on areas printed with Pep-1 SAMs. Cell culture studies demonstrated that low molecular weight HA improved adhesion of human umbilical vein endothelial cells (HUVECs) to the substrate and also stimulated their migration. This research provides insights on the use of of SAMs for the controlled presentation of HA with defined size in cultures of HUVECs to study their functions.
- This article is part of the themed collection: Nanolithography of biointerfaces