Centrifugal precipitation chromatography

The 10th international conference on countercurrent chromatography held at Technische Universität Braunschweig, Braunschweig, Germany, August 1-3, 2018

The 10th International Countercurrent Chromatography Conference (CCC 2018) was held at Technische Universität Braunschweig, Germany, from August 1st-3rd, 2018. The presentations in the scientific program demonstrated the progress in the field of countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC) in recent years and numerous applications have impressively proven the potential of this all-liquid separation technique not only for academic research but also for industry. Special highlights of the conference were the celebration of the 90th birthday of Dr. Yoichiro Ito, the pioneer of countercurrent chromatography, as well as the foundation of an international "Society of Partition and Countercurrent Chromatography (SPCC)".

Development of a novel cross-axis countercurrent chromatographic instrument with six separation columns: Design, dynamics, optimization, prototyping, and experiment

This paper presents the development of a novel cross-axis countercurrent chromatographic instrument (CCCI) with six separation columns, including design, dynamics, optimization, prototype construction, and experimental validation. The conceptual design and the structural design of the cross-axis CCCI are performed while considering the requirements for the separation operation and design. The dynamic analysis is carried out in order to guarantee the local balance and the global balance for the CCCI. The relationship between the mechanical structure parameters and partition efficiency is investigated by analyzing the effect of mechanical structure parameters on the centrifugal force field. By virtue of the modal analysis of the mechanical structure, the critical speed and the weak link of the CCCI are achieved. Aiming at the problem of the weak link, the structural optimization is done. The presented CCCI has six separation columns distributed around the central revolution axis, and it has more separation columns than that of the existing chromatographic instrument. The CCCI has an axial symmetry structure in the three-dimensional space. Thus it can have better dynamics stability than the CCCI having less separation columns with a symmetry structure in the plane. A physical prototype is built, and then the partition efficiency and its effect factors are tested by the single experimental variable method. The results show that the CCCI runs smoothly and has a good retention rate of stationary phase. It is also proved that the developed CCCI has a good partition efficiency on bovine serum albumin and lysozyme.

Continuous Manufacturing of Recombinant Therapeutic Proteins: Upstream and Downstream Technologies

Continuous biomanufacturing of recombinant therapeutic proteins offers several potential advantages over conventional batch processing, including reduced cost of goods, more flexible and responsive manufacturing facilities, and improved and consistent product quality. Although continuous approaches to various upstream and downstream unit operations have been considered and studied for decades, in recent years interest and application have accelerated. Researchers have achieved increasingly higher levels of process intensification, and have also begun to integrate different continuous unit operations into larger, holistically continuous processes. This review first discusses approaches for continuous cell culture, with a focus on perfusion-enabling cell separation technologies including gravitational, centrifugal, and acoustic settling, as well as filtration-based techniques. We follow with a review of various continuous downstream unit operations, covering categories such as clarification, chromatography, formulation, and viral inactivation and filtration. The review ends by summarizing case studies of integrated and continuous processing as reported in the literature.

Novel design for centrifugal counter-current chromatography: VI. Ellipsoid column

A novel ellipsoid column was designed for centrifugal counter-current chromatography. Performance of the ellipsoid column with a capacity of 3.4 mL was examined with three different solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW), hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMH), and 12.5% (w/w) PEG1000 and 12.5% (w/w) dibasic potassium phosphate in water (PEG-DPP) each with suitable test samples. In dipeptide separation with BAW system, both stationary phase retention (Sf) and peak resolution (Rs) of the ellipsoid column were much higher at 0° column angle (column axis parallel to the centrifugal force) than at 90° column angle (column axis perpendicular to the centrifugal force), where elution with the lower phase at a low flow rate produced the best separation yielding Rs at 2.02 with 27.8% Sf at a flow rate of 0.07 ml/min. In the DNP-amino acid separation with HEMW system, the best results were obtained at a flow rate of 0.05 ml/min with 31.6% Sf yielding high Rs values at 2.16 between DNP-DL-glu and DNP-β-ala peaks and 1.81 between DNP-β-ala and DNP-L-ala peaks. In protein separation with PEG-DPP system, lysozyme and myolobin were resolved at Rs of 1.08 at a flow rate of 0.03 ml/min with 38.9% Sf. Most of those Rs values exceed those obtained from the figure-8 column under similar experimental conditions previously reported.

Evaluation of the performance of protein separation in figure-8 centrifugal counter-current chromatography

The performance of protein separation using the figure-8 column configuration in centrifugal counter-current chromatography was investigated under various flow rates and revolution speeds. The separation was performed with a two-phase solvent system composed of polyethylene glycol 1000/potassium phosphate each at 12.5% (w/w) in water and with lysozyme and myoglobin as test samples. In order to improve tracing of the elution curve, a hollow fiber membrane dialyzer was inserted at the inlet of the UV detector. The results showed that the retention of stationary phase (Sf) and resolution (Rs) increased with decreased flow rate and increased revolution speed. The highest Rs of approximately 1 was obtained at a flow rate of 0.01 mL/min under a revolution speed of 1200 rpm with a 3.4 mL capacity column.

Application of centrifugal precipitation chromatography and high-speed counter-current chromatography equipped with a spiral tubing support rotor for the isolation and partial characterization of carotenoid cleavage-like enzymes in Enteromorpha compressa (L.) Nees

Centrifugal precipitation chromatography and a high-speed counter-current chromatography system equipped with a spiral tubing support rotor (spHSCCC) were successfully applied for the identification and isolation of carotenoid cleavage-like enzymes from Enteromorpha compressa (L.) Nees. This is the first study separating active enzymes from a complex natural matrix by spHSCCC. The target enzymes were identified after fractionation of the proteins in an acetone Tris-buffer gradient by centrifugal precipitation chromatography. Also, an aqueous two-phase solvent system consisting of PEG 1000 and mono- and dibasic potassium phosphate was used for the isolation of the enzymes by spHSCCC. The purified fractions contained two proteins of 65 and 72 kDa, respectively. The enzymes could cleave β-carotene and β-apo-8'-carotenal to produce β-ionone.

Studies on the effect of column angle in figure-8 centrifugal counter-current chromatography

The performance of the figure-8 column configuration in centrifugal counter-current chromatography was investigated by changing the angle between the column axis (a line through the central post and the peripheral post on which the figure-8 coil is wound) and the centrifugal force. The first series of experiments was performed using a polar two-phase solvent system composed of 1-butanol-acetic acid-water (4:1:5, v/v) to separate two dipeptide samples, Trp-Tyr and Val-Tyr, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was changed from 0° (column axis parallel to the centrifugal force) to 45° and 45° to 90° (column axis perpendicular to the centrifugal force), peak resolution (Rs) changed from 1.93 (Sf=37.8%) to 1.54 (Sf=30.6%), then to 1.31 (Sf=40.5%) with the lower mobile phase and from 1.21 (Sf=38.8%) to 1.10 (Sf=34.4%), then to 0.99 (Sf=42.2%) with the upper mobile phase, respectively, where the stationary phase retention, Sf, is given in parentheses. The second series of experiments was similarly performed with a more hydrophobic two-phase solvent system composed of hexane-ethyl acetate-methanol-0.1M hydrochloric acid (1:1:1:1, v/v) to separate three DNP-amino acids, DNP-glu, DNP-β-ala and DNP-ala, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was altered from 0° to 45° and 45° to 90°, Rs changed from 1.77 (1st peak/2nd peak) and 1.52 (2nd peak/3rd peak) (Sf=27.3%) to 1.24 and 1.02 (Sf=35.4%), then to 1.69 and 1.49 (Sf=42.1%) with the lower mobile phase, and from 1.73 and 0.84 (SF=41.2%) to 1.44 and 0.73 (Sf=45.6%), then to 1.21 and 0.63 (Sf=55.6%) with the upper mobile phase, respectively. The performance of figure-8 column at 0° and 90° was also compared at different flow rates. The results show that Rs was increased with decreased flow rate yielding the highest value at the 0° column angle with lower mobile phase. The overall results of our studies indicated that a 0° column angle for the figure-8 column enhances the mixing of two phases in the column to improve peak resolution while decreasing the stationary phase retention by interrupting the laminar flow of the mobile phase.

Novel Design for Centrifugal Counter-Current Chromatography: III. Saw Tooth Column

The toroidal coil using an equilateral triangular core and zigzag pattern column have improved both retention of the stationary phase and peak resolution of the conventional toroidal coil in centrifugal counter-current chromatography. To further improve the retention of stationary phase and peak resolution, a novel saw tooth column was designed and the performance of the system was evaluated at various flow rates. The results indicated that both retention of the stationary phase and peak resolution were improved as the flow rate was decreased and at a flow rate of 0.005 ml/min the resolution is remarkably increased. Modification of the tubing called flat-twisted tubing further improved the peak resolution without increasing the column pressure. With a decreased column length at a capacity of about 0.2 ml, resolution of the saw tooth column was 1.02.