Structural and Thermophysical Properties of Magnetic Beads Containing Metallic Nanocrystallites

Cobalt, iron, nickel and iron carbide nanocrystallites, stabilized within carbon beads, were prepared by the three-step procedure including formation of metal acrylamide complex, followed by frontal polymerization and pyrolysis of the polymer at various temperatures. The beads containing the nanocrystallites exhibit domination of the ferromagnetic ordering. The analysis of calorimetric results allowed estimation of the efficiency of the hyperthermal effect, under the influence of an alternating magnetic field. The XTT tests show that the extracts prepared on the basis of the $Fe_3C$ containing beads are nontoxic, whereas these made of the composites containing Co and Ni exhibit negligible cytotoxicity for the test article/vehicle ratios 6.25 and 3.125 mg/ml

Polyurethanes used in the endoprosthesis of joints

The aim of the studies presented in this paper was the selection of the polyurethanes synthesized from different substrates in order to obtain i) ceramic - biodegradable polymer composite and ii) polyurethane resistant to abrasive wear. The polyurethanes were obtained from the crystalline prepolymers extended by water, because it may have a beneficial effect on the toxicity of the material. The properties of PUs were investigated using infrared spectroscopy, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. In all the tested polyurethanes the peak from the reactive -NCO groups was not observed, which indicates that all the substrates are fully reacted. Such polyurethanes are characterized by interesting properties with the perspective use as components of ceramic-polymer joints endoprosthesis. The designed endoprosthesis should fulfill at least three functions: load bearing function (ceramic core), fastening and stabilizing endoprosthesis to the bone (composite ceramics – biodegradable polymer) and tribologic function allowing mating with parts of the prosthesis (polyurethane layer resistant to abrasive wear)