Medical devices having porous layers and methods for making the same
The present invention relates generally to medical devices with therapy eluting components and methods for making same. More specifically, the invention relates to implantable medical devices having at least one porous layer, and methods for making such devices, and loading such devices with therapeutic agents. A mixture or alloy is placed on the surface of a medical device, then one component of the mixture or alloy is generally removed without generally removing the other components of the mixture or alloy.
1 . A stent for insertion into a body structure, comprising:
a stent having:
a first end and a second end,
a lumen extending along a longitudinal axis between the first end and the second end,
an outer surface,
an inner luminal surface; and
at least one porous layer, the porous layer comprising an interstitial structure and an interstitial space;
wherein the interstitial space comprises a branching pore structure having substantially comprising non-linear structures; and
wherein the porous layer is adapted to receive and release at least one drug.
2 . The stent of claim 1 , wherein the interstitial space is generally configured by a dealloying process.
3 . The stent of claim 1 , wherein
at least a portion of the outer surface of the stent comprises a first porous layer; and
at least a portion of the inner luminal surface of the stent comprises a second porous layer.
4 . The stent of claim 3 , wherein at least a portion of the interstitial space of the first porous layer is filled with a drug selected from the group comprising: actinomycin-D, batimistat, c-myc antisense, dexamethasone, paclitaxel, taxanes, sirolimus, tacrolimus and everolimus.
5 . The stent of claim 1 , wherein the porous layer further comprises at least one elution rate altering material within or about at least a portion of the interstitial space of the porous layer.
6 . The stent of claim 1 , wherein the interstitial structure comprises at least one material selected from the group consisting of: gold, silver, nitinol, steel, chromium, iron, nickel, copper, aluminum, titanium, tantalum, cobalt, tungsten, palladium, vanadium, platinum, niobium, a salt, and an oxide particle.
7 . The stent of claim 1 , wherein the interstitial space is configured by removing at least one sacrificial material with a dealloying process.
8 . The stent of claim 1 , wherein the interstitial space is configured by removing at least one sacrificial material with high pressure evaporation.
9 . A drug-eluting stent, comprising:
a stent comprising at least one porous surface comprising an interstitial structure and an interstitial space, wherein the interstitial space is configured generally by the removal of at least a portion of one element from an alloy comprising at least one sacrificial element and one or more structural elements that comprise the interstitial structure of the porous layer.
10 . A method for manufacturing a stent with at least one non-polymeric porous layer, comprising the steps of:
providing a stent having at least one surface; and
depositing a layer of a material onto at least a portion of the surface; the layer of material comprising at least one sacrificial component and at least one structural component and at least one component is not a polymer or drug.
11 . A method of loading a stent with a drug, comprising:
providing a stent having a dealloyed porous zone, the dealloyed porous zone comprising an interstitial structure and an interstitial space; and
filling at least a portion of the interstitial space with at least one drug.
12 . The method of loading a stent with a drug as in claim 11 , further comprising removing a portion of the at least one drug by backsputter or oxygen plasma.
13 . A device for loading porous stents with a drug, comprising:
a vacuum chamber;
a vacuum pump attached to the vacuum chamber,
a drug reservoir;
a flow controller attached to the reservoir; and
14 . A stent for insertion into a body structure, comprising:
a support member comprising:
a first end and a second end,
a lumen extending along a longitudinal axis between the first end and the second end,
an ablumenal surface,
a lumenal surface; and
a porous layer, the porous layer comprising a lower section and an upper section;
wherein the lower section of the porous layer is loaded with an anti-restenosis agent and the upper layer is loaded with an anti-thrombosis agent.