Enhanced corrosion resistance, antibacterial properties, and biocompatibility by hierarchical hydroxyapatite/ciprofloxacin-calcium phosphate coating on nitrided NiTi alloy.

Multi-functional hierarchical coatings are deposited on the nitrided NiTi alloy. The nitrided layer is first deposited by nitrogen plasma immersion ion implantation and a middle layer containing porous hydroxyapatite and ciprofloxacin (Cip) is produced before the top calcium phosphate coating is deposited by the sol-gel method. The thicknesses of the coating and nitrided intermediate layer are about 1.54 µm and 160 nm, respectively and Cip penetrates to a depth of about 530 nm. Calcium phosphate reduces surface defects resulting in a surface roughness of 17 ± 2 nm compared to 34 ± 5 nm of the porous hydroxyapatite coating. The corrosion resistance is improved due to reduced defects and localized corrosion as manifested by the decrease in the Ni2+ release rate by 11.6% from 0.0198 to 0.0175 mg L-1 cm-2. The bacterial resistance against E. coli is also improved by about 88 times on account of Cip release and good biocompatibility is confirmed by proliferation of MC3T3 cells. This multi-functional hierarchical coating has large potential in orthopedic and dental applications.

Microencapsulation of Saffron Petal Phenolic Extract: Their Characterization, In Vitro Gastrointestinal Digestion, and Storage Stability.

Saffron petal, as a byproduct of saffron processing, contains a considerable amount of antioxidant compounds. In the present study, the effect of drying methods (spray and freeze) and different wall structures (maltodextrin and pectin) was investigated on the physicochemical characteristics of microcapsules of saffron petal extracts. Results showed that the increase of the pectin ratio in wall composition leads to the increase of polyphenols content and antioxidant activity of microcapsules. Microencapsulation efficiency and loading capacity in pectin-contained samples were higher than pure maltodextrin samples. Moreover, microcapsules obtained from spray drying method had higher microencapsulation efficiency and loading capacity in comparison with microcapsules obtained from freeze drying method. Also, scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry have been shown to be useful tools for establishing the difference between produced microcapsules. High-performance liquid chromatography was used to evaluate the polyphenolic compounds of the microsphere. The chromatograms obtained from both encapsulation methods indicated high levels of routine in microcapsules of saffron petal extract. In addition, the release of polyphenols from microcapsules of saffron petal extract was evaluated under simulated gastrointestinal conditions. The results indicated that the release behavior of the microcapsules varied according to the type of drying method and wall composition. To assess the shelf life, the microcapsules were kept at different temperatures and relative humidities for 16 weeks. The microcapsules produced by freeze drying and containing high levels of pectin in wall composition had the highest antioxidant activity when kept in relative humidity of 11% and temperature of 4 °C. PRACTICAL APPLICATION: Saffron petal is the huge amount of saffron by-product and contains a number of various antioxidant compounds. Microencapsulation of its valuable compounds results in preventing the destruction of these compounds by environmental factors and their increased bioavailability. Indeed, this paper focuses on the release of microencapsulated powder in the simulated system of the digestive system that helps us to improve the shelf life of the final product during the process and controlled release of compounds in the food and pharmaceutical industries.

Interactions between polyols and wheat biopolymers in a bread model system fortified with inulin: A Fourier transform infrared study.

One of the ways to improve food safety and reduce community health risks is fortification of these products with inulin. Inulin, in spite of the effects and nutritional benefits, will also have undesirable effects on the quality and shelf life of bread. In this study, the interactions between polyols as improvers (i.e. glycerol, sorbitol and propylene glycol) and major biopolymers of wheat flour (i.e. starch and gluten) were examined in model systems fortified with Serish inulin by Fourier transform infrared (FTIR) spectroscopy. The changes in starch structure were estimated focusing on the ratios of the heights of the bands at 1047 and 1022 cm-1 which expresses the quantity of ordered starch to amorphous starch. At first and 5th days of storage, this ratio of control sample was higher than polyol treated samples. It was proved from Gaussian-Lorenzian curve fitting that the relative contribution of characteristic peaks of ß-turns and intramolecular ß-sheets was consecutively increased when polyol proportion of models increased. Whereas, content of intermolecular ß-sheets and α-helix was slightly decreased with increasing of polyols in the models. Briefly, polyols especially 5% propylene glycol, could be used to reduce the undesirable effects of inulin on the quality parameters of dough and bread.