CPC A61L 27/54 (2013.01) [A61F 2/06 (2013.01); A61F 2/90 (2013.01); A61L 27/18 (2013.01); A61L 27/26 (2013.01); A61L 27/58 (2013.01); A61F 2210/0004 (2013.01); A61F 2250/0068 (2013.01); A61L 2300/41 (2013.01); A61L 2300/412 (2013.01); A61L 2300/42 (2013.01)] | 10 Claims |
1. A degradable vascular stent capable of avoiding late restenosis, comprising:
a base region formed by a polylactic acid based polymer; at least one storage region in which an active agent is stored; and
an outer layer of a drug sustained release coating covered on the base region and/or the storage region;
wherein before the mass of the polylactic acid based polymer of the base region is decreased by 10-20%, the active agent in the storage region is retained in structural units of the polylactic acid based polymer;
wherein after the mass of the polylactic acid based polymer of the base region is decreased by 10-20%, the active agent in the storage region is released from the storage region;
wherein the storage region is formed of an alkaline degradable polymer or a mixture of a polylactic acid based polymer and an alkaline degradable polymer; and
wherein after the mass of the polymer of the base region is decreased by 10-20%, the alkaline degradable polymer is hydrolyzed to release alkaline monomers.
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