Nanoparticle formation of chitosan induced by 4-sulfonatocalixarenes: utilization for alkaloid encapsulation

Spontaneous formation of positively charged nanoparticles was observed upon mixing more than stoichiometric amount of chitosan with 4-sulfonatocalix[8]arene (SCX8) in acidic solution. The particle size did not change with SCX8 concentration, polymer chain length, and the degree of deacetylation at 0.002 ≤ SCX8/chitosan ≤0.043 molar ratios in 0.01 M HCl. However, larger aggregates were produced when chitosan concentration was increased. The most stable nanoparticles with 160 nm diameter and narrow size distribution were obtained at pH 4 using low molecular weight chitosan. These particles encapsulated coralyne with more than 90 % entrapment efficiency and 15 % loading capacity. A loading ratio of [coralyne]/[SCX8] = 1.7 was achieved without any stability loss. 4-Sulfonatocalix[4]arene induced the formation of slightly smaller nanoparticles than its homologs comprising 6 or 8 phenol units. © 2016, Springer-Verlag Berlin Heidelberg

4-Sulfonatocalixarene-induced nanoparticle formation of methylimidazolium-conjugated dextrans: Utilization for drug encapsulation

Methylimidazolium side groups were grafted via ether linkage to dextran and the self-assembly of these polymers with 4-sulfonato-calix[n]arenes (SCXn) was studied in aqueous solutions. Dynamic light scattering and zeta potential measurements revealed the mixing ratio ranges of the constituents where stable nanoparticles could be created. The macrocycle size of SCXn and the molecular mass of the polymer barely affected the nanoparticle diameter, but the lowering of the imidazolium degree of substitution substantially diminished the stability of the associates. The pH change from neutral to acidic also unfavourably influenced the self-organization owing mainly to the decrease of the SCXn charge. Cryogenic transmission electron microscopy images proved the spherical morphology of the nanoproducts in which the stoichiometry of the constituents was always close to the one corresponding to charge compensation. The flexible and positively charged dextran-chains are compacted by the polyanionic SCXn. Coralyne, a pharmacologically important alkaloid was efficiently embedded by self-assembly in the produced nanoparticles reaching 99% association efficiency. © 2019 Elsevier Lt

Crystal and molecular structure ofN-phenyl substituted 1,2-, 2,3- and 1,8-naphthalimides

The three structures were solved by direct methods and refined by full-matrix least-squares procedure. 2-phenyl-1 H-benz[f]isoindole-1,3(2 H)-dione, (compound 1): orthorhombic, space group Pcab, a = 7.618(1) Angstrom, b = 11.717(2) Angstrom, c = 28.540(4) Angstrom, V = 2547.4(7) Angstrom(3), Z = 8 and d = 1.425 Mg m(-3), R = 0.038 (Rw = 0.038) for 190 parameters and 820 observations with I > 2.5 sigma(I). 2-phenyl-1 H-benz[e]isoindole-1,3 (2 H)-dione (compound 2): orthorhombic, space group Pc2(1)b, a = 6.7042(9) Angstrom, b = 7.4589(9) Angstrom, c = 26.441(7) Angstrom, V = 1322.4(4) Angstrom(3), Z = 4 and d = 1.373 Mg m(-3), R = 0.037 (Rw = 0.032) for 190 parameters and 1186 observations with I > 3 sigma(I). 2-phenyl-1 H-benz[de]isoquinoline-1,3(2 H)-dione (compound 3): monoclinic, space group C2/c, a = 13.501(3) Angstrom, b = 13.212(4) Angstrom, c = 8.305(2) Angstrom, beta = 116.24(2 degrees, V = 1329(9) Angstrom(3), Z = 4, and d = 1.366 Mg m(-3), R = 0.038 (Rw = 0.033) for 71 parameters and 754 observations with I > 3 sigma(I). The plane of the N-phenyl substituent has an axis which lies in the plane of the naphthalimide part and passes by the carbon atom bound to the nitrogen atom and by the carbon in para position. It makes a dihedral angle with the plane of the naphthalimide moiety of 59.2 degrees, 46.5 degrees and 69.4 degrees for the compounds 1, 2 and 3 respectively. This difference in geometry between the three molecules brings new insights into their spectroscopic properties

Reversible Nanoparticle–Micelle Transformation of Ionic Liquid–Sulfonatocalix[6]arene Aggregates

The effect of temperature and NaCl concentration variations on the self-assembly of 1-methyl-3- tetradecylimidazolium (C14mim+) and 4-sulfonatocalix[6]- arene (SCX6) was studied by dynamic light scattering and isothermal calorimetric methods at pH 7. Inclusion complex formation promoted the self-assembly to spherical nanoparticles (NP), which transformed to supramolecular micelles (SM) in the presence of NaCl. Highly reversible, temperature-responsive behavior was observed, and the conditions of the NP−SM transition could be tuned by the alteration of C14mim+:SCX6 mixing ratio and NaCl concentration. The association to SM was always exothermic with enthalpy independent of the amount of NaCl. In contrast, NPs were produced in endothermic process at low temperature, and the enthalpy change became less favorable upon increase in NaCl concentration. The NP formation was accompanied by negative molar heat capacity change, which further diminished when NaCl concentration was raised

Removal of hormones and pharmaceuticals in the Advanced Water Recycling Demonstration Plant in Queensland, Australia

An advanced water recycling demonstration plant was employed to investigate the effectiveness of a number of treatment technologies in the removal of some residuals of commonly prescribed pharmaceuticals as well as natural and synthetic hormones found in sewage. Analysis of targeted compounds was carried out by solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). Initial tests were undertaken to determine the background concentrations of the analytes during various stages of treatment. Subsequent tests, undertaken by spiking with standard solutions of the target compounds provided further information on the removal efficiencies of some selected treatment modules. The results of the study indicate that while ozonation, microfiltration and nanofiltration were partially effective; treatment by reverse osmosis was the most universally successful in the removal of the target residuals. While significantly more data is required for a full evaluation, this initial investigation suggests that reverse osmosis may be an effective means of removing a wider range of pharmaceutically active residuals and hormones from treated sewage

Profiling of ERBB receptors and downstream pathways reveals selectivity and hidden properties of ERBB4 antagonists

ERBB receptor tyrosine kinases are involved in development and diseases like cancer, cardiovascular, neu rodevelopmental, and mental disorders. Although existing drugs target ERBB receptors, the next gener ation of drugs requires enhanced selectivity and understanding of physiological pathway responses to improve efficiency and reduce side effects. To address this, we developed a multilevel barcoded reporter profiling assay, termed ‘ERBBprofiler’, in living cells to monitor the activity of all ERBB targets and key physiological pathways simultaneously. This assay helps differentiate on-target therapeutic effects from off-target and off-pathway side effects of ERBB antagonists. To challenge the assay, eight estab lished ERBB antagonists were profiled. Known effects were confirmed, and previously uncharacterized properties were discovered, such as pyrotinib’s preference for ERBB4 over EGFR. Additionally, two lead compounds selectively targeting ERBB4 were profiled, showing promise for clinical trials. Taken together, this multiparametric profiling approach can guide early-stage drug development and lead to improved future therapeutic interventions