Co-delivery of docetaxel and doxorubicin using biodegradable PEG-PLA micelles for treatment of breast cancer with synergistic anti-tumour effects

Poly(ethylene glycol)-poly(lactic acid) copolymer, prepared by ring opening polymerization, was used as a single platform to co-deliver both hydrophilic doxorubicin and hydrophobic docetaxel (DTX) in a simulated physiological environment. The average size of the negatively charged drug loaded polymeric micelles were found to be 293 nm. The drug loading (%) and encapsulation efficiency (%) were calculated to be 1.21 and 59.0, respectively. The in vitro cytotoxicity test using MCF7 breast cancer cells was conducted using 1 × 10⁴ cells in 10% FBS and 1% antibiotic, and the absorbance of formazan was evaluated at 570 nm. Cell growth inhibition by MTT assay showed viability of 33% of the MCF7 cells after treatment with drug-loaded micelles for 48 h. Controlled release of drugs from the polymeric micelles indicated a burst release effect initially; whereas, 98% of drug could be released at pH 7.4 within a time period of 96 h. Time period for drug release shorten to 48 h only in simulated mild acidic pH (5.4) condition. The in vitro drug release study from micelles indicated synergistic cytotoxicity effect in human metastatic breast cancer MCF7 cell.     

Synthesis and Stability of Lanthanum Superhydrides

Recent theoretical calculations predict that megabar pressure stabilizes very hydrogen‐rich simple compounds having new clathrate‐like structures and remarkable electronic properties including room‐temperature superconductivity. X‐ray diffraction and optical studies demonstrate that superhydrides of lanthanum can be synthesized with La atoms in an fcc lattice at 170 GPa upon heating to about 1000 K. The results match the predicted cubic metallic phase of LaH₁₀ having cages of thirty‐two hydrogen atoms surrounding each La atom. Upon decompression, the fcc‐based structure undergoes a rhombohedral distortion of the La sublattice. The superhydride phases consist of an atomic hydrogen sublattice with H?H distances of about 1.1 Å, which are close to predictions for solid atomic metallic hydrogen at these pressures. With stability below 200 GPa, the superhydride is thus the closest analogue to solid atomic metallic hydrogen yet to be synthesized and characterized.     

Recent advances in N-heterocycles synthesis through catalytic C−H functionalization of azobenzenes

Azobenzenes are well known as crucial structural motifs used in material sciences, nonlinear optical devices, and pharmaceuticals. They also represent an important class of organic intermediates for the transformation of azo and azoxy groups into various useful molecules. Azo groups have a dual character, both electronically increasing the reactivity of the aryl ring and controlling the site-selectivity of the reaction, which significantly increases their utility in organic synthesis. As a complement to previous protocols, the strategy of transition-metal-catalyzed C–H activation of azobenzenes using various coupling partners, such as alkenes, alkynes, aldehydes, diazo esters, organic azides, and sulfoxonium ylides, has recently emerged as a powerful tool to create the corresponding heterocycles. Thus, this review focuses on the recent progress on the direct synthesis of N-heterocycles via C(sp²)–H functionalization of azobenzenes using transition-metal catalysis. This review includes most of the reported methods until the beginning of 2018.     

Use of combinatorial library screening to identify inhibitors of a bacterial two-component signal transduction kinase

Bacterial resistance to antibiotics is emerging as amajor concern to the medical community. Theappearance of several antibiotic-resistant strains,including multidrug-resistant Staphylococcusaureus, raises the prospect that infections by thesebacteria could soon become untreatable with currentlyavailable antibiotics. In order to address thisproblem, increased emphasis is being placed on thediscovery of novel classes of antibacterial agentsthat inhibit novel molecular targets using sources ofcompounds not yet exploited for antibiotic drugdiscovery. Novel classes of compounds can now berapidly investigated using combinatorial chemistryapproaches. This report describes the identificationof novel antibacterial compounds from a combinatoriallibrary of N-acetylated, C-amidated D-amino acidhexapeptides. This library of compounds was screenedfor inhibitors of CheA, a member of the bacterialtwo-component signal transduction kinase family. Several peptides with apparent IC₅₀ values in thelow micromolar range were identified. In addition toinhibiting CheA, these peptides inhibited mammalianprotein kinase C (from rat brain) with comparablepotency. Finally, these peptides were also found tohave significant antibacterial properties, althoughthe true mechanism by which they exhibited inhibitionof bacterial growth remains uncertain.     

QCD at finite temperature—a variational approach

We develop here a nonperturbative framework to study quantum chromodynamics (QCD) at finite temperatures using the thermofield dynamics (TFD) method of Umezawa. The methodology considered here is selfconsistent and variational. There is a dynamical generation of a magnetic gluon mass. This eliminates the infrared problems associated with perturbative QCD calculations at finite temperatures. We obtain here the thermodynamical quantities like free energy density, pressure and entropy density. We also calculate the temperature dependence of SVZ parameter . The condensate vanishes at the critical temperature in accordance with recent hot sum rule calculations. The present method gives an insight to the vacuum structure in QCD at zero temperature as well as at finite temperatures in a coordinated manner.     

Spectrophotometric determination of zinc at trace level in environmental samples

Summary Zinc is selectively extracted with N-hydroxy-N,N-diphenylbenzamidine and spectrophotometrically determined with 4-(2-pyridylazo)resorcinol. The molar absorptivity is 9.4×10⁴l·mol^–1 cm^–1. Relative standard deviation is ±1.5%.