Polyethyleneimine incorporated chitosan/α-MnO2 nanorod honeycomb-like composite foams with remarkable elasticity and ultralight property for the effective removal of U(VI) from aqueous solution.

The development of new adsorbents is needed to address the environmental challenges of radioactive wastewater treatment. Herein we reported a novel polyethyleneimine incorporated chitosan/α-MnO2 nanorod honeycomb-like composite (PCM) foam with remarkable elasticity and ultralight property for U(VI) removal. Among different PCM sorbents, PCM-40 possessed the highest sorption capacity for U(VI) due to its highly developed macroporous structure and high content of amine/imine groups. The kinetics were well-simulated by the pseudo-second-order model, indicating chemisorption as the rate-controlling step. The isotherms could be described by the Langmuir model, suggesting mono-layer homogeneous sorption of U(VI). The maximum sorption U(VI) capacity for PCM-40 reaches up to 301.9 mg/g at pH 4.5 and 298 K. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption process. The main sorption mechanism is related to the complexation of uranyl ions with the amine/imine and hydroxyl groups. The high sorption capacity, fast kinetic rate and relatively good selectivity of PCM-40 highlights its promising application in radioactive pollution cleanup.

Selective biosorption of U(VI) from aqueous solution by ion-imprinted honeycomb-like chitosan/kaolin clay composite foams.

The radioactive pollution caused by the discharge of radioactive wastewater poses a serious threat to public health and ecosystem stability owing to its long-term detriments. Herein, the ion-imprinted honeycomb-like chitosan/kaolin clay (ICK) composite foams were successfully fabricated and applied to the selective biosorption of U(VI) from aqueous solution. It was found that the ICK-2 was the best among various ICK foams owing to its well-developed honeycomb-like structure and the presence of abundant functional groups. As compared to the non-imprinted sorbent (NICK-2), the ion-imprinted sorbent (ICK-2) presents higher sorption and better selectivity since it can smartly recognize the target ions. The sorption isotherms was well-fitted with Langmuir model, and the maximum sorption capacity of ICK-2 was evaluated as 286.85 mg/g for U(VI) at 298 K and pH 5.0. The kinetic data could be described by pseudo-second order model. The FTIR and XPS results suggest that both amine and hydroxyl groups are responsible for U(VI) coordination. The ICK-2 presents high sorption capacity, good selectivity and fast kinetic rate, and thus it has potential application for U(VI) separation from radioactive wastewater.

Hierarchically Nanostructured Fe3O4/C Composite as a Promising Magnetic Targeted Drug Nanocarrier.

Nanostructured Fe3O4/C composites are very attractive for high-performance magnetic targeted drug carriers. Herein, Fe3O4/C composite nanospheres with good dispersity are prepared by a simple one-step hydrothermal synthesis and subsequent heat treatment in Ar. The composite nanospheres consist of clustered primary nanoparticles, and exhibit a hierarchical architecture with a high specific surface area of 119.3 m² g-1. The Fe3O4/C composite nanospheres show a high saturation magnetization value of 101 emu g-1 and good biocompatibility. In particular, the composite nanospheres deliver a large loading content (85.8%) of epirubicin hydrochloride (EPI), resulting from their unique composition and microstructure. More importantly, the release of EPI from the EPI-loaded magnetic carrier (Fe3O4/C-EPI) may be enhanced by both a slightly acidic environment and a rotating magnetic field induced by a simple motor-driven magnet system. The above favorable properties make the hierarchical Fe3O4/C composite sample a promising candidate for magnetic targeting nanocarriers of EPI.

Simultaneous determination of six major stilbenes and flavonoids in Smilax china by high performance liquid chromatography.

A simple, sensitive and specific HPLC method was developed for simultaneous determination of the six major active constituents in Smilax china, namely taxifolin-3-O-glycoside (1), piceid (2), oxyresveratrol (3), engeletin (4), resveratrol (5) and scirpusin A (6), respectively. The samples were separated on an Aglient Zorbax XDB-C18 column with gradient elution of acetonitrile and 0.02% phosphoric acid (v/v) at a flow rate of 1.0 ml/min and detected at 300 nm. The six target compounds were completely separated within 35 min. All calibration curves showed good linearity (r2>0.999) within test ranges. The reproducibility was evaluated by intra- and inter-day assays and R.S.D. values were less than 3.7%. The recoveries were between 93.7 and 103.0%. The method was successfully applied to the analysis of six constituents in 15 commercial samples of S. china. The results indicated that the developed HPLC assay was readily utilized as a quality control method for S. china.

Chemical fingerprint and metabolic fingerprint analysis of Danshen injection by HPLC-UV and HPLC-MS methods.

HPLC-UV and HPLC-MS techniques were used in fingerprint analysis of Danshen injection and its raw materials (roots and rhizoma of Salvia miltiorrhiza). HPLC profiles of Danshen injections from a Chinese pharmaceutical factory and their raw materials were established as their characteristic fingerprint and employed to assess their consistency and difference. To develop the representative fingerprint of Danshen injection, 10 batches of samples were analyzed under the same HPLC conditions. The results showed that 10 batches of Danshen injections had very similar HPLC fingerprints. To characterize the major constituents of Danshen injection for quality control, 11 major chromatographic peaks were characterized by their MS spectra and comparison with the reference standards. Through comparison of the HPLC profiles of Danshen injection with its raw material, it was found that they are greatly different, which indicated the changes of major constituents in the course of preparation procedure. In addition, the rat's plasma was analyzed by HPLC-MS technique after intravenous administration of Danshen injection at different time intervals to explore the in vivo metabolism of the major active constituents. Except for protocatechuic aldehyde, the major phenolic acids in Danshen injection appeared in rat's plasma after intravenous administration, but quantity of each phenolic acids was very different from that in Danshen injection. With the administration time prolonged danshensu and salvianolic acid B disappeared quickly, salvianolic D, lithospermic acid and salvianolic A slowly decreased and maintained relatively high concentration after 30 min of intravenous administration. This indicated that polyphenolic acids were significant for biological activity of Danshen injection. It might be concluded that chemical fingerprint combined with metabolic fingerprint is a useful means to control the quality and to clarify the possible mechanism of action of herbal products.

HPLC determination and pharmacokinetic studies of salvianolic acid B in rat plasma after oral administration of Radix Salviae Miltiorrhizae extract.

A precise and reproducible HPLC method has been established and validated for determination of salvianolic acid B (SalB) in rat plasma after oral administration of Radix Salviae Miltiorrhizae extract. Liquid-liquid extraction was adopted for the sample preparation. Separation was accomplished on a C(18) column with a linear gradient elution consisting of acetonitrile and aqueous phosphoric acid. Ultraviolet detection was at 280 nm. The method was validated over the concentration range 10.8-259.4 microg/mL using 1 mL of plasma. The assay was linear over this concentration range with a coefficient of variation less than 7%. The extraction recovery of SalB was within the range 71-83% with RSD 11%. The mean recovery of the internal standard was 84% (n = 6) with RSD of 5.6%. This method is suitable to determine SalB in plasma and to investigate the pharmacokinetics of SalB.