Effect of Co-presentation of Adhesive Ligands and Short Hyaluronan on Lymphendothelial Cells.

Controlled activation of lymphangiogenesis through functional biomaterials represents a promising approach to support wound healing after surgical procedures, yet remains a challenge. In a synthetic biological approach, we therefore set out to mimic the basal microenvironment of human primary dermal lymphatic endothelial cells (LECs) during lymphangiogenesis. As the extracellular matrix component hyaluronan (HA) regulates lymphangiogenesis, we designed a bifunctional surface in which adhesive peptide ligands and short HA oligosaccharides (sHA) tethered to nanoparticles are copresented to the basal side of LECs in a controlled, concentration-dependent manner. Exposure of LECs to sHA in solution to mimic luminal stimulation of the cells did not result in modified metabolic activity. However, LECs grown on the bifunctional adhesive surfaces showed a biphasic change in metabolic activity, with increased metabolic activity being observed in response to increasing nanoparticle densities up to a maximum of 540 particles/µm2. Thus, interfaces that concomitantly present adhesive ligands and sHA can stimulate LEC metabolism and might be able to trigger lymphangiogenesis.

Controlled Immobilization Strategies to Probe Short Hyaluronan-Protein Interactions.

Well-controlled grafting of small hyaluronan oligosaccharides (sHA) enables novel approaches to investigate biological processes such as angiogenesis, immune reactions and cancer metastasis. We develop two strategies for covalent attachment of sHA, a fast high-density adsorption and a two-layer system that allows tuning the density and mode of immobilization. We monitored the sHA adlayer formation and subsequent macromolecular interactions by label-free quartz crystal microbalance with dissipation (QCM-D). The modified surfaces are inert to unspecific protein adsorption, and yet retain the specific binding capacity of sHA. Thus they are an ideal tool to study the interactions of hyaluronan-binding proteins and short hyaluronan molecules as demonstrated by the specific recognition of LYVE-1 and aggrecan. Both hyaladherins recognize sHA and the binding is independent to the presence of the reducing end.