Quantification of Monoclonal Antibodies from Bioreactor Supernatants Using Protein-G Sepharose Chromatography

A protein-G sepharose affinity chromatography was validated to quantify antibodies from cell culture supernatants. The calibration curve linear range was 30–480 μg immunoglobulin (IgG). Between-run study demonstrated a coefficient of variation 5.73–9.02% in 20 purification cycles and sample dilution with protein-free medium (>3 mL) showed a marked IgG amount over estimation. Sensitivity was 30 μg, and bovine serum albumin addition to columns did not affect IgG recovery (?90%). CB.Ifn-2.4 antibody quantification in MiniPERM^® bioreactor supernatant reached 1.5 mg mL^?1, coinciding with concentration measured by ELISA and thus demonstrating the protein-G sepharose column accuracy used to quantify IgG under these experimental conditions.     

Heterocycles as key substrates in multicomponent reactions: the fast lane towards molecular complexity

Heterocycles display an intrinsic reactivity which enables rich, versatile and productive transformations. Taking into account their ubiquitous presence in natural products and drugs, the development of new, fast and efficient preparative protocols for these structures remains an urgent task in Organic Synthesis. Multicomponent reactions using heterocyclic chemistry offer new possibilities to exploit this exclusive reactivity. Recent results show relevant examples of such transformations. Several approaches which allow the construction of complex heterocyclic compounds from simple starting materials using this principle have been analyzed.     

Information-theoretical complexity for the hydrogenic identity S N 2 exchange reaction

We investigate the complexity of the hydrogenic identity S _N 2 exchange reaction by means of information-theoretic functionals such as disequilibrium (D), exponential entropy (L), Fisher information (I), power entropy (J) and joint information-theoretic measures, i.e., the I–D, D–L and I–J planes and the Fisher–Shannon (FS) and López-Mancini-Calbet (LMC) shape complexities. The several information-theoretic measures of the one-particle density were computed in position (r) and momentum (p) spaces. The analysis revealed that the chemically significant regions of this reaction can be identified through most of the information-theoretic functionals or planes, not only the ones which are commonly revealed by the energy, such as the reactant/product (R/P) and the transition state (TS), but also those that are not present in the energy profile such as the bond cleavage energy region (BCER), the bond breaking/forming regions (B–B/F) and the charge transfer process (CT). The analysis of the complexities shows that the energy profile of the identity S _N 2 exchange reaction bears no simple behavior with respect to the LMC and FS measures. Most of the chemical features of interest (BCER, B–B/F and CT) are only revealed when particular information-theoretic aspects of localizability (L or J), uniformity (D) and disorder (I) are considered.     

Preparation and Z-Scan nonlinear optical characterization of Au/SiO2- and Ag/SiO2-supported nanoparticles dispersed in silica sonogel films

Au/SiO₂ and Ag/SiO₂ supported metal-nanoparticles (MNPs) were implemented to fabricate SiO₂-based inorganic?Cinorganic hybrid sonogel films. Prepared Au/SiO₂- and Ag/SiO₂-MNPs exhibited low 2D-HCP crystallinity with particle diameters below 10?nm and homogeneous size distribution. The catalyst-free (CF) sonogel route was successfully implemented to produce these optically active nanocomposite films by doping the liquid sol-phase with these MNP systems and its subsequent deposition onto glass substrates via standard spin-coating procedures. The easy MNP-loading within the mesoporous dielectric sonogel network evidenced a huge chemical affinity between the silica sonogel hosting system and the guest SiO₂-supported MNPs. This fact allowed us to fabricate high quality hybrid films suitable for cubic nonlinear optical (NLO) characterizations via the Z-Scan technique. Indeed, the hosting sonogel network provided adequate thermal and mechanical stability protecting the active MNPs from environment conditions and diminished their tendency to aggregate; thus, preserving their pristine optical properties and morphology, giving rise to stable sol?Cgel hybrid films appropriate for photonic applications. Comprehensive morphological, structural, spectroscopic and nonlinear photophysical characterizations were optimally performed to the developed hybrid films. Our results have shown that the crystalline nature of the implemented MNPs, their small sizes and appropriate guest?Chost stabilizing interactions play a crucial role in the observation of improved cubic NLO-properties of these MNP structures embedded within the highly pure CF-sonogel confinement.     

Enhancement of Fatty Acid‐based Polyurethanes Cytocompatibility by Non‐covalent Anchoring of Chondroitin Sulfate

For tissue engineering purpose biopolymer chondroitin sulfate (CS), one of the major components of cartilage and bone extracellular matrix, was immobilized onto the surface of amino‐functionalized polyurethane (PU) films derived from naturally occurring oleic and 10‐undecenoic acids. The amino‐functionalized PUs were prepared by aminolysis with 1,6‐hexamethylenediamine of synthesized PUs containing methyl ester groups. FTIR‐ATR, XPS, SEM, and water contact angle measurements were used to confirm the surface changes at each step of treatment, both in morphologies and chemical composition. Cytotoxicity and cell morphology analysis using osteoblast cell line MG63 showed that PU‐CS films are suitable materials for cell growth, spreading, and differentiation.

     

Imaging histamine in live basophils and macrophages with a fluorescent mesoionic acid fluoride

Histamine is a biogenic amine with fundamental roles in circulatory and immune systems. We report a fluorescent small molecule (Histamine Blue) for imaging intracellular histamine in live basophils and macrophages. Histamine Blue is a fluorescent mesoionic acid fluoride that turns on upon reaction with histamine. The selective response of Histamine Blue enabled the visualization of intracellular histamine under different physiological conditions.     

Step-economic synthesis of (+)-crocacin C: a concise crotylboronation/[3,3]-sigmatropic rearrangement approach

The step-economic total synthesis of (+)-crocacin C has been achieved in 20% yield from commercially available starting materials. This approach requires the isolation of only 8 intermediates and can provide a reliable supply of (+)-crocacin C for the development of new antifungal and crop protection agents.     

Formal synthesis of (+)-crocacin C

The formal synthesis of (+)-crocacin C is reported. The approach described takes advantage of a highly regioselective epoxide cuprate addition and a diastereoselective Overman rearrangement. The synthesis is practical and amenable to scale up.     

Quantitative thin-film x-ray microanalysis by STEM/HAADF: statistical analysis for precision and accuracy determination.

Silicon-germanium thin films have been analyzed by EDS microanalysis in a field emission gun scanning transmission electron microscope (FEG-STEM) equipped with a high angular dark-field detector (STEM/HAADF). Several spectra have been acquired in the same homogeneous area of the cross-sectioned sample by drift-corrected linescan acquisitions. The Ge concentrations and the local film thickness have been obtained by using a previously described Monte Carlo based "two tilt angles" method. Although the concentrations are in excellent agreement with the known values, the resulting confidence intervals are not as good as expected from the precision in beam positioning and tilt angle position and readout offered by our state-of-the-art microscope. The Gaussian shape of the SiKalpha and GeKalpha X-ray intensities allows one to use the parametric bootstrap method of statistics, whereby it becomes possible to perform the same quantitative analysis in sample regions of different compositions and thicknesses, but by doing only one measurement at the two angles.     

Modulation invariant bilinear <Emphasis Type="Italic">T</Emphasis>(1) theorem

We prove a T(1) theorem for bilinear singular integral operators (trilinear forms) with a one-dimensional modulation symmetry.