US Patent 9987130 Decalcifying heart valve

Vascular valve systems for treating calcified vascular vessel valves by delivery of one or more calcium chelating agents are described. The vascular valve system includes an expandable stent; a valve with a plurality of leaflets, and a hydrogel layer disposed on an outer surface of the stent. The hydrogel layer includes a hydrogel, and a calcium-chelating agent and an acidifying agent disposed within the hydrogel. The calcium-chelating agent and the acidifying agent are covalently bonded to the hydrogel. The hydrogel layer is configured to capture loosened calcium deposits to form a calcium-chelating agent complex covalently bonded to the hydrogel layer. Methods of making the vascular valve systems are also described.