A multi-articular fracture fixation device having a adjustable modulus of rigidity. As an example of a particularly preferred specific application of these compounds, the present invention encompasses the use of the MIPs as sequestrants in the gastrointestinal tract, particularly in order to bind and therefore remove toxins from the gastrointestinal tract. An inflatable valve selectively obstructs the passageway based upon a controlled supply of high pressure air to the inflatable valve. In yet another aspect, the at least one conductive element comprises a metal sheet, film or coating of paramagnetic or diamagnetic material that is relatively highly conductive.