Multizone Implants
Medical devices having more than one degradation zone or degradation mechanism are used for orthopedic repair devices and soft tissue fixation devices.
1 . An implant comprising at least two degradation zones, each degradation zone having a degradation rate, the at least two degradation zones including a first degradation zone which degrades by surface erosion and a second degradation zone which degrades by bulk erosion.
2 . The implant according to claim 1 , wherein the at least two degradation zones comprise materials selected from the group consisting of polyesters, polyester polyalkylene oxide copolymers, polyorthoesters, polyhydroxybutyrates, polyhydroxyalkanoates, polyanhydrides, polyamines, polycarbonates, copolymers and combinations thereof.
3 . The implant according to claim 1 , wherein the first degradation zone and the second degradation zone comprise different compositions.
4 . The implant according to claim 1 , wherein the first degradation zone comprises a composition that is the same composition as a composition of the second degradation zone.
5 . The implant according to claim 1 , further comprising a bioactive agent.
6 . The implant according to claim 1 , wherein at least one degradation zone comprises a polymer drug.
7 . The implant according to claim 1 , wherein the degradation rate of at least one degradation zone corresponds to an elution of at least one bioactive agent.
8 . The implant according to claim 7 , wherein a first bioactive agent is released as the first degradation zone undergoes surface erosion.
9 . The implant according to claim 7 , wherein a second bioactive agent is released as the second degradation zone undergoes bulk erosion.
10 . The implant according to claim 1 , wherein the implant may be selected from the group consisting of orthopedic repair devices and soft tissue repair devices.
11 . The implant according to claim 1 , wherein the orthopedic repair device is selected from the group consisting of spinal fixation devices, nucleus repair devices, fracture plates, wires, pins, screws, anchors, intramedullary devices, artificial ligaments and artificial tendons.
12 . The implant according to claim 10 , wherein the soft tissue repair device is selected from the group consisting of mesh, sutures, pledgets, buttresses, and tacks.
13 . The implant according to claim 1 , further comprising an interphase between the first degradation zone and the second degradation zone.
14 . The implant according to claim 1 , further comprising an interface between the first degradation zone and the second degradation zone.
15 . The implant according to claim 1 , wherein the first degradation zone and the second degradation zone degrade at different rates.
16 . The implant according to claim 1 , wherein the first degradation zone and the second degradation zone have different degradation mechanisms.
17 . The implant according to claim 1 , further including an osteoconductive inorganic phase.
18 . The implant according to claim 1 , wherein at least one degradation zone comprises a porous structure.