Polymerized degradable hyaluronan--a platform for stent coating with inherent inhibitory effects on neointimal formation in a porcine coronary model

Biodegradable hyaluronan (hyaluronic acid, HA) made insoluble by self-cross-linking in the presence of N-(3-dimethylaminopropyl)-N'-ethyl carbodiimide (EDC) has been used to cover stents. The maximum polymer-mass on a 16-mm stainless steel stent is approximately 2 mg. During manual crimping and simulated application, the loss of polymerized HA is negligible. The insoluble HA coating has an advantageous inherent antiproliferative effect regarding neointimal formation after local vessel wall injury (overstretch model) and leads to a reduced inflammatory response compared to uncoated stainless-steel stents, used as control, in undiseased pig coronary arteries, over a follow-up period of four weeks. Thus, cross-linked HA stent coating warrants further research as an interactive degradable biomaterial with an inherent inhibitory effect on neointimal formation as a possible biomatrix for local drug delivery to reduce restenosis rate.