Interpenetrating polymer networks
IPN compositions and methods of making the same are provided. The IPN compositions can include a water swellable, water permeable IPN or semi-IPN member with a first polymer network including a hydrophobic thermoset or thermoplastic polymer, a second polymer network including a non-ionic polymer, and a third polymer network including an ionic polymer containing sulfonic acid functional groups that are otherwise difficult to form composites with hydrophobic polymers. The IPN compositions can be used in orthopedic implants or in mechanical applications as a bearing material.
1. An interpenetrating polymer network (IPN) or semi-IPN member comprising a first polymer network including a hydrophobic thermoset or thermoplastic polymer including multiple subsets of polymer segments, a second polymer network comprising a polymerized non-ionic monomer, and a third polymer network including an ionic polymer containing sulfonic acid groups, wherein the second network is non-ionic, the third network is ionic, the second and third polymer networks are each formed within the same subset of polymer segments of the hydrophobic thermoset or thermoplastic polymer, and the first, second, and third polymer networks are not bonded to each other covalently.
2. The IPN or semi-IPN member of claim 1 , wherein the IPN or semi-IPN member comprises a lubricious surface having a coefficient of friction of less than about 0.1.
3. The IPN or semi-IPN member of claim 1 , wherein the first polymer network comprises a polyurethane.
4. The IPN or semi-IPN member of claim 1 , wherein the second polymer network comprises one or more polymerized non-ionic monomers selected from dimethylacrylamide (DMAA), acrylamide, N-isopropyl acrylamide (NIPAAm), hydroxyethyl acrylate, hydroxyethyl methacrylate, vinyl alcohol, methyl acrylate, hydroxyethyl acrylamide, hydroxyethyl methacrylamide, and N-vinyl pyrrolidone.
5. The IPN or semi-IPN member of claim 1 , wherein the second polymer network comprises a plurality of different monomers.
6. The IPN or semi-IPN member of claim 1 , wherein the ionic polymer containing sulfonic acid groups comprises a polymerized monomer having sulfonic acid functional groups.
7. The IPN or semi-IPN member of claim 1 , wherein the ionic polymer containing sulfonic acid groups comprises a polymerized macromer having sulfonic acid functional groups.
8. The IPN or semi-IPN member of claim 1 , wherein the ionic polymer containing sulfonic acid groups comprises a polymerized sulfonate-containing monomer selected from acrylamide methyl propane sulfonic acid (AMPS), 2-Propene-1-sulfonic acid, 1,3-Propanesulfone, 1,4 butane sulfone, anetholesulfonic acid, styrenesulfonic acid, vinyl sulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, or 2-methyl-2-propene-1-sulfonic acid.
9. The IPN or semi-IPN member of claim 1 , wherein the second polymer network, the third polymer network, or both is polymerized in the presence of a cross-linker.
10. The IPN or semi-IPN member of claim 9 , wherein the cross-linker is selected from ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate (or diacrylate), triethylene glycol dimethacrylate (or diacrylate), tetraethylene glycol dimethacrylate (or diacrylate), polyethylene glycol dimethacrylate, or polyethylene glycol diacrylate, methylene bisacrylamide, N,N′-(1,2-dihydroxyethylene) bisacrylamide, derivatives, or combinations thereof.
11. An orthopedic implant comprising the IPN or semi-IPN of claim 1 .
12. The orthopedic implant of claim 11 , wherein the orthopedic implant is adapted to fit an acromioclavicular joint, an ankle joint, a condyle, an elbow joint, a hand joint including a metacarpal joint, a finger joint, a thumb joint, a base of thumb joint, a glenoid, a hip joint including an acetabular joint, an intervertebral disc, a vertebral joint, including an intervertebral facet joint, a labrum, a meniscus, a foot joint, including a metatarsal joint and a toe joint, a patella, a tibial plateau, a jaw joint including a temporomandibular joint, a knee joint including a knee medial compartment joint, a patellofemoral joint, and a total knee joint, a knee meniscus, a shoulder joint including a labral joint, or a wrist joint and any portion thereof.
13. The orthopedic implant of claim 11 , wherein the orthopedic implant is selected from cartilage replacement devices, joint replacement devices, meniscal replacements, interpositional spaces, tendon or ligament replacement or augmentation devices, cartilage scaffolds, cartilage replacement plugs, cartilage stimulation plugs, bone filler implants to stimulate cartilage regeneration, and facet or vertebral disc implants.
14. The orthopedic implant of claim 11 , wherein the IPN or semi-IPN member comprises a bearing surface and an attachment zone.
15. The orthopedic implant of claim 14 , wherein the bearing surface has a coefficient of friction of less than about 0.1.
16. The orthopedic implant of claim 15 , comprising a bone interface member attached to the attachment zone.
17. The orthopedic implant of claim 16 , wherein the bone interface member comprises a metal.