Interpenetrating polymer networks

The implant of any of the preceding claims, wherein the third polymer network comprising an ionic polymer containing sulfonic acid groups includes polymerized monomers comprising one or more of:

• 2-acrylamido 2-methyl propane sulfonic acid (AMPS), 2-Propene-1-sulfonic acid, 2-Methyl-2-propene-1-sulfonic acid, 1,3-Propanesulfone, 1,4 butane sulfone, vinyl sulfonic acid, anetholesulfonic acid, and styrenesulfonic acid.

The implant of any of the preceding claims, wherein the third polymer network comprising the ionic polymer containing sulfonic acid groups includes polymerized 2-acrylamido 2-methyl propane sulfonic acid (AMPS) and acrylic acid.

The implant of any of the preceding claims, wherein the third polymer network comprising the ionic polymer containing sulfonic acid groups comprises about 1% to about 100% sulfonic acid groups relative to a total number of functional groups of the third polymer network.

The composition of any of the preceding claims, wherein the bearing surface has a coefficient of friction of less than about 0.1.

The composition of any of the preceding claims, wherein the bearing surface has a coefficient of friction of less than about 0.01.

The composition of any of the preceding claims, wherein the bearing surface has a coefficient of friction of less than about 0.005.

The implant of any of the preceding claims, wherein the compositional gradient forms a stiffness gradient.

The implant of any of the preceding claims, wherein one of the second and third polymer networks forms a composition and hydration gradient from a first portion of the implant to a second portion of the implant.

The implant of any of the preceding claims, wherein the bone interface member comprises a metal.

The implant of any of the preceding claims, wherein the bone interface member comprises a ceramic or a polymer.

The implant of any of the preceding claims, wherein at least a portion of the orthopedic implant is configured to change a shape during implant placement in a joint.

The implant of any of the preceding claims, wherein at least a portion of the implant is configured to transiently deform during implant placement in a joint.

The implant of any of the preceding claims, wherein an attachment of the attachment zone to the bone interface member is created by an adhesive.

The implant of any of the preceding claims, wherein the third polymer network comprising the ionic polymer third polymer network comprises a fixed charge.

The implant of any of the preceding claims, wherein the implant has a shape selected from the group consisting of:

• a cap, a cup, a plug, a mushroom, a cylinder, a patch, and a stem.

The implant of any of the preceding claims, wherein the implant is adapted to fit an acromioclavicular joint, an ankle joint, a condyle, an elbow joint, a finger joint, a glenoid, a hip joint, an intervertebral disc, an intervertebral facet joint, a labrum, a meniscus, a metacarpal joint, a metatarsal joint, a patella, a tibial plateau, a toe joint, a temporomandibular joint, or a wrist joint and any portion thereof.

The implant of any of the preceding claims, wherein the first polymer network comprises polyurethane.

The implant of any of the preceding claims, further comprising:

• an additive within the water swellable, water permeable IPN or semi-IPN member, the additive including one or more of:
• a steroid, anti-inflammatory agent, antioxidant, antibiotic, and anti-microbial agent.

The implant of any of the preceding claims, further comprising an adhesive gradient between the attachment zone and the bearing surface, the adhesive gradient having a highest concentration of adhesive at the attachment zone.

A composition comprising:

• a water swellable, water permeable interpenetrating polymer network (IPN) or semi-IPN member comprising a first polymer network comprising a hydrophobic thermoset or thermoplastic polymer, a second polymer network comprising a non-ionic polymer, and a third polymer network comprising an ionic polymer containing sulfonic acid functional groups, the water swellable, water permeable IPN or semi-IPN member including a compositional gradient between a first surface and a second surface.