Manganese ferrite modified biochar from vinasse for enhanced adsorption of levofloxacin: Effects and mechanisms.

The primitive biochar (BC) and NiFe2O4/biochar composites (NFBC), biological adsorbents prepared from vinasse wastes, possess the environmental application in levofloxacin (LEV) removal. In this study, the efficient adsorption of LEV onto biochar synthesized by pyrolysis of vinasse wastes from aqueous environment was investigated. The influencing factors (i.e., pH, reaction time, and temperature) of adsorption process were also well studied. The results indicated that the maximum adsorption capacities of both BC and NFBC were occurred in mildly acidic condition (pH 6). In addition, the biochar adsorption capacities were obviously increased in higher temperature (25-45 °C). The chemistry adsorption and monolayer homogeneous dominated adsorption process of LEV onto BC and NFBC. The adsorption process was spontaneous and endothermic by thermodynamic analysis. The SEDA (site energy distribution analysis) explained that the adsorption effectivity increased by increasing site energy of biochar surface. The SEDA revealed the more energy heterogeneity in NFBC, fitting the characterization result of Fourier-transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The electron-donor-acceptor (EDA) interactions and hydrogen bonds is suggested as the major adsorption mechanism. And as for the adsorption of the various biowaste recycled synthetic, this study can be referred in discussion of performance analysis and optimal condition.

Cytochalasins from an endophytic fungus Phoma multirostrata XJ-2-1 with cell cycle arrest and TRAIL-resistance-overcoming activities.

Nine new (1-9) and four known (10-13) [13]cytochalasins, along with three known 24-oxa[14]cytochalasins (14-16), were isolated from the culture of Phoma multirostrata XJ-2-1, an endophytic fungus obtained from the fibrous root of Parasenecio albus. Their structures were elucidated by interpretation of the nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS). The absolute configurations were assigned by single-crystal X-ray crystallography, modified Mosher's method, and by analysis of their experimental electronic circular dichroism (ECD) spectra. Compound 6 could induce cell cycle arrest at G2-phase in CT26 and A549 cells, and displayed moderate cytotoxicity against CT26 and A549 cell lines with IC50 values of 6.03 and 5.04 µM, respectively. Co-treatment of 7-9, 13 and 16 with tumor necrosis factor related apoptosis inducing ligand (TRAIL) could significantly decrease the cell viability of A549, which revealed that cytochalasins could possibly be a new group of TRAIL sensitizers in lung cancer therapy.

Ergocytochalasin A, a polycyclic merocytochalasan from an endophytic fungus Phoma multirostrata XJ-2-1.

Ergocytochalasin A (1), an unprecedented merocytochalasan formed via Diels-Alder cycloaddition of a cytochalasin with an ergosterol, was isolated from an endophytic fungus Phoma multirostrata XJ-2-1. Compound 1 possessed a unique 5/6/14/6/5/6/6/6 fused octacyclic ring system and its structure was established by detailed NMR and HRESIMS spectroscopic analyses. The absolute configuration of 1 was determined by single-crystal X-ray diffraction. A plausible biogenetic pathway of 1 was postulated. Compound 1 was evaluated for its cytotoxicity against six cancer cell lines and showed inhibitory effects with IC50 values ranging from 6.92 to 26.63 µM. The in vitro immunosuppressive activity of 1 against ConA-induced T cell and LPS-induced B cell proliferation, as well as its antiviral activity against Human dengue virus type 3 (DV3), influenza A virus (H1N1) and respiratory syncytial virus (RSV), was also evaluated. Ergocytochalasin A is the first example of a merocytochalasan which consists of one cytochalasin moiety and one ergosterol moiety. Containing eighteen chiral centers, ergocytochalasin A owns a folded framework, which makes it extremely compact in space.

Research progress on the removal of hazardous perfluorochemicals: A review.

Perfluorinated substances are global and ubiquitous pollutants. The persistent organic pollution of perfluorochemicals (PFCs) have drawn attentions worldwide. In view of the current need for sustainable development, many researchers began to study the remediation techniques for PFCs. Due to its unique hydrophobic and oil-phobic characteristics, the requirements for the PFCs removal process are different, so that their remediation techniques are still under continuous exploration. Hence, this review summarized the removal behaviors of various PFCs on different materials which supply a good foundation for future investigations in this field. It is evident from previous literature that every remediation techniques for PFCs has its own advantages. Among various currently evaluated removal methods, adsorption seems to be one of the most commonly used and recognized techniques for PFCs pollution control. Other innovative and promising techniques, such as physical and/or chemical methods, have also been tested for their effectiveness in removing perfluorinated compounds.

A sustainable ferromanganese biochar adsorbent for effective levofloxacin removal from aqueous medium.

This present study reported the synthesis and characterization of a low-cost, environment friendly and high efficient biochar, ferromanganese modified biochar (Fe/Mn-BC) for the removal of levofloxacin (LEV) from aqueous medium. Fe/Mn-BC was synthesized through the facile co-precipitation of Fe, Mn with vinasse wastes and then pyrolysis under controlled conditions. The characterization of Fe/MnBC was analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction patterns (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman. Some influencing factors (e.g., pH, Fe/Mn-BC dosage, initial LEV concentration, ionic strength, contact time and temperature) were comprehensively investigated. The results manifested that the adsorption process of LEV onto Fe/Mn-BC was high pH dependence and the maximum adsorption capacity was achieved at pH 5. Moreover, the adsorption capacity of LEV was increased with increasing ionic strength. To gain a clearer perspective on the adsorption behavior of LEV onto Fe/Mn-BC, the adsorption kinetics and isotherms were also performed, revealing pseudo-second-order and Freundlich model had a better fitting effect. Reusability experiments indicated that Fe/Mn-BC could maintain a certain adsorption capacity for LEV after 5 recycles. Overall, this work showed that Fe/Mn-BC was an effective and promising adsorbent for eliminating LEV from aqueous medium.

Analyses of tetracycline adsorption on alkali-acid modified magnetic biochar: Site energy distribution consideration.

As a widely used antibiotic, tetracycline has a huge hidden danger to human health. Municipal sludge rich in organic substances has the potential to produce biochar. In this work, the municipal sludge biochar from solid waste was modified by the alkali-acid binding method, and tetracycline was efficiently removed from the aqueous solution, the adsorption removal efficiency reached to 86% at initial concentration of 200 mg/L. The activation energy was determined by analyzing the adsorption kinetics at different temperatures and tetracycline concentrations. The results showed that tetracycline adsorption on modified biochar was endothermic reaction. Presenting the Langmuir-Freundlich model, adsorption site energy distributions was reckoned. The average adsorption site energy and corresponding standard deviation of the adsorption site energy distribution were deduced emphatically to inquiry the strength of tetracycline adsorption on modified biochar and the adsorption site heterogeneity. The method proposed of research further proves that modified biochar from sewage sludge remove tetracycline from contaminated water has great potential, and exploration of tetracycline adsorption mechanisms by quantifying average site energy. The results and methods of this work can be transferred to study water treatment systems.

Selective self-induced stimulus amplification prodrug platform for inhibiting multidrug resistance and lung metastasis.

Tumor heterogeneity is considered as one of main obstacles to limit the clinical application of stimuli-responsive nanocarriers. Multidrug resistance (MDR) is also a major challenge in cancer chemotherapy. Here, we developed a tumor redox heterogeneity-responsive prodrug with self-induced reactive oxygen species (ROS) amplification property for facilitating rapid drug release and overcoming MDR and lung metastasis. The prodrug can self-assemble into polymer micelles (PMs) with high drug loading content (~30%), good physiological stability, prolonged systemic circulation and enhanced tumor distribution. Moreover, the prodrug PMs can stimulate tumor-specific ROS signal amplification, which provided a replenishment of consumed ROS necessary for rapid and complete drug release. The elevated ROS could not only evoke the mitochondria-dependent apoptosis by caspase-9/3 activation, but also inhibit inherent and acquired drug resistance by altering expression of Bcl-2 protein family and by reducing mitochondria membrane potential (ΔΨm) and ATP level in cancer cells. As a result, the prodrug PMs showed enhanced efficacy for inhibiting tumor growth in S180 sarcoma tumor model and in drug-resistant tumor model MCF-7/ADR and preventing lung metastasis in 4T1 in situ breast cancer model. This novel approach reported here may provide a promising strategy in the design of stimuli-responsive nanocarriers for efficient therapy of multidrug resistant and metastatic tumor.

Tumor Microenvironment Responsive Nanogel for the Combinatorial Antitumor Effect of Chemotherapy and Immunotherapy.

A biomimetic nanogel with tumor microenvironment responsive property is developed for the combinatorial antitumor effects of chemotherapy and immunotherapy. Nanogels are formulated with hydroxypropyl-ß-cyclodextrin acrylate and two opposite charged chitosan derivatives for entrapping anticancer drug paclitaxel and precisely controlling the pH responsive capability, respectively. The nanogel supported erythrocyte membrane can achieve "nanosponge" property for delivering immunotherapeutic agent interleukin-2 without reducing the bioactivity. By responsively releasing drugs in tumor microenvironment, the nanogels significantly enhanced antitumor activity with improved drug penetration, induction of calreticulin exposure, and increased antitumor immunity. The tumor microenvironment is remodeled by the combination of these drugs in low dosage, as evidenced by the promoted infiltration of immune effector cells and reduction of immunosuppressive factors.