Hollow porous implants filled with mesoporous silica particles as a two-stage antibiotic-eluting device.

A new type of implantable drug eluting device is presented, consisting of a bed of mesoporous microparticles packed inside a reservoir with a porous wall. This provides two sets of variables for drug release control that can be tailored independently. The first is related to the microparticles (packing density, size and pore structure) and the second to the reservoir (pore diameter and thickness of the wall, permeation area).

Effect of Nitinol surface treatments on its physico-chemical properties.

The main purpose of this work is the study of different physicochemical treatments on Nitinol slabs and wires, with the aim of inducing the formation of a TiO(2) surface film capable of increasing the corrosion resistance of the material and of reducing the release of Ni when the Nitinol samples were immersed in simulated body fluid (SBF). To this end, a battery of measurements (surface roughness, contact angle, electrochemical corrosion, chemical analysis as a function of depth, and Ni release to SBF) has been used to characterize Nitinol commercial samples, as received, and also after the different treatments performed. The results clearly indicate the effectiveness of the passivation TiO(2) layer as a barrier against Ni leaching, and the detrimental effects of any processes (such as polishing or cutting) that result in exposure of areas not coated by the TiO(2) film.