Effect of Ultrasonic Treatment on Structure, Antibacterial Activity of Sugarcane Leaf Polysaccharides.

This study investigated the impact of ultrasonic extraction (UE) on the structure and in vitro antibacterial activity of polysaccharides from sugarcane leaves (SLW). Native sugarcane leaf polysaccharides were treated with ultrasound (480 W) for 3 h to yield sugarcane leaf polysaccharides (SLU). Compared to SLW (33.59 kDa), the molecular weight of SLU (13.08 kDa) was significantly decreased, while the monosaccharide composition of SLU was unchanged. The results of SEM and XRD indicated that UE significantly changed the surface morphology of SLW and destroyed its inner crystalline structure. In vitro experiments showed that SLU had stronger antibacterial activity. These findings revealed that UE treatment could alter the tertiary structure of SLW but had no impact on its primary structure. Furthermore, the antibacterial activity of SLW could be greatly enhanced after UE treatment. As a bioactive additive, SLU has great application potential in functional foods, cosmetics, and pharmaceuticals.

Improved cathodic oxygen reduction and bioelectricity generation of electrochemical reactor based on reduced graphene oxide decorated with titanium-based composites.

A kind of reduced graphene oxide decorated with titanium-based (RGO/TiO2) composites are successfully synthesized and employed in this current study as a novel nonprecious metal catalyst for enhancing bioelectricity generation and cathodic oxygen reduction reaction (ORR) in single chamber microbial fuel cells (MFCs). Compared with commercial Pt/C, RGO/TiO2 shows obviously enhanced oxygen reduction reaction activity due to the appropriately-permeated, large electrochemical active area, enough exposure of electrocatalytic active sites of RGO/TiO2. The air-cathode MFC with RGO/TiO2-1 cathode achieves 1786.7 mW m-3 of power density, 86.7% ±â€¯1.2% of COD removal and 31.6% ±â€¯1.1% of CE, which are higher than commercial Pt/C. Moreover, RGO/TiO2-1 cathode exhibits high-effective electrocatalytic activity, and the power density of RGO/TiO2-1 can keep a stable level and only has a minor decline (5.35%) during 30-cycles operation. These results indicate that RGO/TiO2-1 is a potential cathode catalyst, markedly enhancing cathode ORR, wastewater treatment efficiency, and bioelectricity generation of MFC.

Fabrication and characterization of hydroxyapatite/sodium alginate/chitosan composite microspheres for drug delivery and bone tissue engineering.

Hydroxyapatite/sodium alginate/chitosan (HA/SA/CS) composite microspheres, which possess good biocompatibility for specific biomedical application, were prepared using an emulsion crosslink technique; calcium ions were used as a cross-linking agent. The effect of the concentration of sodium alginate (SA), the volume ratio of water to oil, the content of hydroxyapatite (HA) nanoparticles, as well as rotation speed, on the morphology and dispersion of composite microspheres were investigated. Also investigated were the drug loading, release behaviors, in vitro hemolysis activity, cytotoxicity, cell adhesion and proliferation capacity of the materials. The results demonstrate that the HA/SA/CS composite microspheres were successfully prepared; their drug loading and encapsulation efficiency are much higher than that of HA nanoparticles. Dox-loaded HA/SA/CS composite microspheres show good pH-sensitive drug-release capability. The hemolysis and cytotoxicity tests suggest that the microspheres have good blood and cell compatibility. Furthermore, the prepared composite microspheres display better cell adhesion and proliferation capacity than HA nanoparticles and HA/SA composite microspheres. Therefore, the HA/SA/CS composite microspheres might have potential as drug carriers in a pH-responsive controlled-release drug delivery system and as candidates for application in bone tissue engineering.