[Study of the Anti-corrosion and Anti-fretting Properties of Surfi cial Treated magnesium Alloy Bone Plate].

The weakening of mechanical properties caused by rapid degradation has been an impediment to the clinical application of magnesium aloy for a long time. In this paper, the effect of surface treatment on the anti-corrosion and anti-fretting properties of magnesium aloy ZK60 was studied. Firstly, an oxidizing layer whose outer layer was porous was first made on the surface of magnesium aloy through micro-arc oxidation treatment (MAO). Then ahydroxyapatitecoating was fabricated by electrodeposition on the oxidizing layer to seal the porous layer. The corrosion resistance and fretting performance of them were investigated in vitro under a simulated bone-plate service condition. Polarization testing results showed that both of them can signifi cantly enhanced the corrosion resistance of magnesium aloy and the corrosion resistance of the latter was better. The fretting testing results showed that obvious coatingfl aking occurred on the worn surface of the latter, and its anti-fretting properties are inferior to that of the former.

A fungal cellulose nanocrystals-based approach to improve the stability of triterpenes loaded Pickering emulsion.

Depolysaccharide residues of edible fungus Pleurotus eryngii (dePSR-Pe), a mushroom industry waste, have abundant cellulose. In this study, the cellulose nanocrystals of P. eryngii (PeCNs) were extracted by hydrochloric acid. Results showed that the length of PeCNs is 469 ± 76.41 nm with a high aspect ratio of 40-100 and needle morphology. The structural characterization revealed that PeCNs had good thermal stability (approach 300 °C) and high crystallinity (84.2 %). An O/W Pickering emulsion stabilized with PeCNs was prepared to inhibit lipid oxidation and improve the loading capacity of triterpenes of P. coco. Unimodal size distribution of emulsion droplets was obtained under an optimized aqueous-phase condition to form a metastable emulsion, regardless of varying oil-water volume ratio <50/50. In vitro digestion study suggested that triterpenes-loaded Pickering emulsion had 1-3 times higher drug stability than bulk oil. These metastable Pickering emulsions call for fewer nanoparticles and provide a new strategy for the industry application of cellulose nanocrystals at less cost.