Investigation into the hot workability of the as-extruded WE43 magnesium alloy using processing map.

The research concerned the characterization of the hot-working behavior of the as-extruded WE43 magnesium alloy potentially for biomedical applications and the construction of processing maps to guide the choice of forming process parameters. Isothermal uniaxial compression tests were performed over a temperature range of 350-480°C and strain rate range of 0.001-10s(-1).

Multipass cold drawing of magnesium alloy minitubes for biodegradable vascular stents.

Magnesium alloys possess highly limited room-temperature formabilities. This presents a technological barrier to the fabrication of minitubes for biodegradable vascular stents. The research was aimed at developing precision forming technology to fabricate ZM21 magnesium alloy minitubes with a refined microstructure.

Porous TiO₂ surface formed on nickel-titanium alloy by plasma electrolytic oxidation: a prospective polymer-free reservoir for drug eluting stent applications.

In this study, a porous oxide layer was formed on the surface of nickel-titanium alloy (NiTi) by plasma electrolytic oxidation (PEO) with the aim to produce a polymer-free drug carrier for drug eluting stent (DES) applications. The oxidation was performed galvanostatically in concentrated phosphoric acid electrolyte at low temperature. It was found that the response of NiTi substrate during the PEO process was different from that of bulk Ti, since the presence of large amount of Ni delayed the initial formation of a compact oxide layer that is essential for the PEO to take place.

Characterization of Porous TiO2 Surfaces Formed on 316L Stainless Steel by Plasma Electrolytic Oxidation for Stent Applications.

In this study, a porous oxide layer was formed on the surface of 316L stainless steel (SS) by combining Ti magnetron sputtering and plasma electrolytic oxidation (PEO) with the aim to produce a polymer-free drug carrier for drug eluting stent (DES) applications. The oxidation was performed galvanostatically in Na3PO4 electrolyte. The surface porosity, average pore size and roughness varied with PEO treatment duration, and under optimum conditions, the surface showed a porosity of 7.

In vitro degradation behavior and bioactivity of magnesium-Bioglass(®) composites for orthopedic applications.

To improve the bioactivity and degradation behavior of biodegradable magnesium, biodegradable metal matrix composites with the ZK30 magnesium alloy as the matrix and bioactive glass (BG, 45S5) as the reinforcement were prepared. The microstructures of the ZK30-BG composites showed homogeneous dispersion of BG particles throughout the matrix. XRD and EDX analyses confirmed the retention of the morphological characteristics and composition of BG particles in the composites.

Magnesium-based composites with improved in vitro surface biocompatibility.

In this study, bioactive glass (BG, 45S5) particles were added to a biodegradable magnesium alloy (ZK30) through a semi-solid high-pressure casting process in order to improve the surface biocompatibility of the biomaterial and potentially its bioactivity. The observation of the as-cast microstructures of ZK30-BG composites indicated homogeneous dispersion of BG particles in the matrix. SEM, EDX and EPMA showed the retention of the morphological characteristics and composition of BG particles in the as-cast composite materials.

Drug release from PLGA microspheres attached to solids using supercritical CO₂.

Functionalization of a porous orthopedic implant with dexamethasone, a widely used anti-inflammatory drug, encapsulated within a biodegradable polymer for controlled release could help reduce or eliminate the inflammation response by the local tissue. In this research, we investigated the possibility of using supercritical carbon dioxide (CO₂) for attaching dexamethasone-loaded PLGA (polylactic-co-glycolic acid) microspheres to porous CoCrMo alloy for continuous delivery of dexamethasone. Supercritical CO₂ has been shown to be effective for attachment of PLGA microspheres to glass plates and porous CoCrMo alloy.

In vitro antibacterial activity of porous TiO2-Ag composite layers against methicillin-resistant Staphylococcus aureus.

The aim of this study was the synthesis of a porous TiO(2)-Ag composite coating and assessment of its in vitro bactericidal activity against methicillin-resistant Staphylococcus aureus. The coating was produced by plasma electrolytic oxidation of Ti-6Al-7Nb medical alloy in a calcium acetate/calcium glycerophosphate electrolyte bearing Ag nanoparticles. Following oxidation, the surface of the titanium substrate was converted into the corresponding oxide (TiO(2)) bearing Ca and P species from the electrolyte.