Coronary stents having biodegradable layers

摘要

Disclosed is a coated stent comprising (i) a stent framework; (ii) a plurality of layers deposited on said stent framework in dry powder form to form said coated stent; wherein at least one of said layers comprises a bioabsorbable polymer and at least one of said layers comprises one or more active agents; wherein at least part of the active agent is in crystalline form; and wherein forming said layers comprises sintering under conditions that do not substantially modify the activity of said active agent. A method of preparing a coated stent is also disclosed, wherein the method comprises the steps of:(i) providing a stent framework;(ii) depositing a plurality of layers on said stent framework to form said coated stent; wherein at least one of said layers comprises a bioabsorbable polymer; wherein depositing said plurality of layers on said stent framework comprises:discharging at least one pharmaceutical agent and/or at least one active biological agent in dry powder form through a first orifice; depositing the pharmaceutical agent and/or active biological agent dry powder particles onto said framework, wherein an electrical potential is maintained between the framework and pharmaceutical agent and/or active biological agent dry powder particles; discharging the bioabsorbable polymer through said first orifice or through a second orifice; depositing the bioabsorbable polymer in dry powder form onto said framework, wherein an electrical potential is maintained between the framework and the bioabsorbable polymer dry powder particles; and sintering under conditions that do not substantially modify the morphology of said pharmaceutical agent and/or the activity of said bio logical agent.