Armoring Vascular Implant by Glycocalyx-Mimetic Coating with Clustered Morphology and Hydrophilic Lubrication

The endothelial glycocalyx is a natural protective layer for blood vessels. Efficient construction of a reliable glycocalyx-mimetic coating on a vascular implant possesses great potential but remains a challenge. Herein, a novel glycocalyx-mimetic coating featuring the clustered morphology and hydrophilic lubrication is developed via the layer-by-layer self-assembly of polyethyleneimine (PEI) and phosphorylcholine-modified hyaluronic acid (HA-PC). The zwitterionic PC groups in HA-PC exhibited an anti-polyelectrolyte effect to induce the molecular folding and aggregation of HA in solution and enhance its binding capacity to PEI, resulting in an endothelial glycocalyx-mimetic clustered morphology. Besides, zwitterions, rather than hydrophobic groups, can achieve hydrophilic lubrication properties through spatial synergy with HA while inducing the molecular folding of HA, ultimately constructing a glycocalyx-mimetic coating. Such a coating can function well as armor to vascular stent, by virtue of excellent anti-coagulation, anti-inflammation, and endothelial promotion properties in vivo and in vitro. The findings not only provide new insights into the interactions between PC-modified polyelectrolytes but also render a promising glycocalyx-mimetic coating to armor vascular implants.